MICROWAVE FOOD PRODUCT AND METHOD

Abstract: Method and means for controlling heating of multi-component foods in a microwave oven. The means and methods include the use of a layer of edible substance with preselected properties and positioned adjacent to one or more food items to control the amount of transmitted microwave power to the adjacent food. One or more layers of edible susbtance has properties selected in relation to the other food substance such that effective shielding or control is achieved which will reliably control the heating of the components of the food product in the time required for heating one or more portions of the multi-component food product. With preselected values for thickness and dielectric properties of one or more layers and the thermal masses of the layers and the other components, the amount of energy transmitted to one or more of the food components and its final temperature can be effectively and reliably controlled.

Description: MICROWAVE FOOD PRODUCT AND METHOD Background of the Invention This Application is a Continuation-In-Part of Application Serial Number 903,007 filed September 2, 1986, the disclosure of which e*r 5 including that found in the claims is incorporated herein by reference. The present invention relates to a means and methods of controlling the heating of foods in a microwave oven, primarily to 10 achieve differential heating between two or more edible substances positioned adjacent one another in a πrulti-component food product. It has been found that the desired degree of control by one food and hence the amo nt of heating of the other food is determined by certain physical properties of the food products. IS In the heating of foods in a microwave oven, temperature differentials and differential heating have been achieved through the use of package shielding material. For example, it has long been practiced in microwave cooking to use microwave reflective 20 packaging with various sized apertures to control the amount of microwave radiation simultaneously impinging on various foods. Such reflective packaging was metal or contained metal. The foods desired to be heated were separated in the package with each food having one or more preselected apertures in the shield adjacent the 25 food. The heating of each food was tuned by selecting the SUBSTITUTE SHEET appropriate size and/or shape of the aperture to achieve a desired temperature within the heating time of the package. Such packaging was relatively effective for certain food concepts which allowed "H«5" separation of the components, but was expensive and required empirical design to be effective. A major drawback to such an approach was that it required that each individual food component be in a separate compartment to separate each of the food substances to achieve the proper heating of each component. Another major drawback was that the shielding material was metal. In years past oven manufacturers objected to and recommended against the use of metal in a microwave oven for fear of possible damage to the oven circuitry and because metal packaging can cause arcing which is a consumer detriment. Further, metal shielding is difficult to use with some packaging materials and is also expensive. Numerous patents have addressed some of these problems, see for example, U. S. Patents 4,081,646, 4,233,325, and 4,122,324. To date, shielding of foods has been a packaging function and no one has been commercially successful in achieving controlled simultaneous heating of two or more foods absent this type of shielding. Even in the use of two of more food components together, no one has taught how to select properties of the control food to SUBSTITUTE SHEET function as a microwave energy, transmission inhibitor adjacent to and between the source of microwave energy and another food or how to select properties of one food component to accomplish controlled heating of other food components. Further, even with the above described metal shielding being available it has found little use and most microwave heating is still done until the foods being simultaneously heated reach some temperature with little or no control of the balance of the heating. Likewise, U.S. Patents 2,600,566 to Moffet and 2,714,070 to Welch, when read in context, discuss the need for metallic shielding "packaging" to control heating of multi-component food systems. Further, these particular packaging concepts do not appear to be disposable, but appear to be permanent receptacles. Both patents discuss the concept of differential temperatures, for example, between a sauce and an ice cream through the use of metal shielding. Neither Welch nor Moffet discusses controlled heating of one food with a shielding or control food via control of the thickness, and dielectric properties of the shielding layer. For example, Welch states in columns 3 and 4, "Due to the action of shield 45, energy from the cooker 10 can penetrate the food body only from the top, thereof, through paper member 50. Since the sauce 49 is a relatively high loss substance, it will absorb substantially all the microwave energy passing therethrough with the result that little or no microwave energy passes into the ice cream SUBSTITUTE SHEET body 47. The ice cream body 47 thus remains frozen and, due to the ice crystals therein, substantially entirely reflects any energy which does pass thru sauce 49 back into sauce 49. Since the cake member 48 is a relatively good heat insulator, the ice cream body 47 is not melted to any substantial extent by conductive heat from the sauce 49.... The resulting product is an ice cream having a hot fudge sauce which may be eaten directly from the paper container 46 inside the shield member 45." Surprisingly, it has been found that by control of the thickness, and microwave load (a combination of dielectric proper-ties of a control layer and the thermal loads) or by the control of thickness and dielectric constant of a control layer and the thermal loads of each component highly effective cooking control can be achieved. Thermal load can be defined as specific heat in calories/gram multiplied by the mass in grams. Another dimension of thermal performance is thermal diffusivity which is defined as the thermal conductivity (heat input rate in calories/seconds multiplied by distance in centimeters multiplied by temperature difference in degrees centigrade) divided by density and specific heat of the product. It has been found that certain foods can achieve a reflectance of about 65% and a transmission of as low as 20% or even lower, e.g., 10%, for high water layers, of the incident power and can function as aa effective shield within given time constraints. Further, it was surprisingly found through calculation that SUBSTITUTE SHEET conductive heat transfer from the shielding component to the shielded food component, when made in accordance with the invention, had little practical effect on heating of the shielded component within the short time that is required to heat many foods in a microwave oven, making it possible to allow the shielding layer to heat without detriment to the shielded layer. These factors make it possible to use edible foods or edible substances as shields to control heating of other foods in a microwave environment reducing the need for metal or other nonedible shields and insulating layers. The result is the ability to make new types of microwave foods and food systems that cannot be properly heated together in any other manner. Given the physical characteristics of the components of the food system and a desired amount of differential heating it is possible to design multiple component food systems with controlled differential heating or temperatures at the end of microwave heating which overcome the above problems. Figure 1 is a side sectional view of a multi-component food product. Figure 2 is a graph showing the functional relationship between temperature differential and heating time for various multi-component food systems having different intermediate control SUBSTITUTE SHEET layers: metal foil, control sauce with 24% water, a silicone foam insert, a high moisture sauce with 37% water, and no intermediate layer. Figure 3 is a graph showing a functional relationship between the temperature and heating time of a shielded component of a multi-component food system as shown in Figure 1 with different intermediate layer thicknesses. Figure 4 is a graph showing a functional relationship between ice cream temperature and heating time of products in a multi-component food system as shown in Figure 1 with and without, an intermediate sauce layer. Figure 5 is a graph showing a functional relationship between the temperature of a brownie in a multi-component food system as shown in Figure 1 and heating time for systems with and without an intermediate layer of shielding sauce. Figure 6 is a graph showing a functional relationship between temperature differential, i.e., the temperature of the brownie minus the temperature of the ice cream as a function of heating time for a multi-component food system as shown in Figure 1 with and without an intermediate layer of sauce. SUBSTITUTE SHEET Figure 7 is a graph showing a functional relationship between temperature di ferential, i.e., the temperature of the brownie minu the temperature of the ice cream, as a function of heating time for a multi-component food system as shown in Figure 1 with different shielding layer thicknesses using the control sauce with 24% free water. Figure 8 is a three dimensional representation of a mathematical model showing a functional relationship between temperature differential, microwave heating time, and sauce thickness for the control sauce having a free water content of 24% for a multi-component food system as- shown in Figure 1 having ice cream and brownie on opposite sides of the shielding layer. Figures 9A, B, and C are graphs showing functional relationships between four variables; reflected power, absorbed power, shielded power, and relative heating rate (absorbance thickness) each as a function of shielding layer thickness for a shield layer having relative dielectric constant (E* ) (hereinafter dielectric constant) values of 13, 26, and 39 and relative dielectric loss factor (E") (hereinafter dielectric loss factor) values of 3.5, 7.0, and 10.5, respectively. E* is the real part and E" is the imaginary part of the complex permittivity as is well known to those skilled in the art. See, for example, A. Von Hippel, Dielectric Materials and Applications. MIT Press, 1954. SUBSTITUTE SHEET Figures 90, E, F, and G are graphs showing functional relationships between four variables? reflected power, absorbed power, shielded power, and relative heating rate. When these figures are viewed in combination with Figure 9B they show the effect of changing E' or E" while holding the other constant. Figure 10 is a graph showing a functional relationship between the temperature differential between sauce layer and ice cream for a currently existing product called Hot Scoop which is ice cream and sauce in an unshielded paper cup compared to a product similar to that shown in Figure 1 having a control sauce layer and ice cream, but with metal shielding on the side of the container also as shown in Figure 1. The limitations on this graph, are discussed hereinafter. Figure 11 is a graph showing a comparison of heating temperature profiles of ice cream as- a function of heating time in a microwave oven for two Hot Scoop products and the invention using ice cream, brownie, and sauce in a metal shielded cup. Figure 12 shows a functional relationship between shear force necessary to shear broccoli after heating in microwave oven for broccoli which was prepared in a microwave oven for a given period of time with no shielding cheese sauce, broccoli with a shielding cheese sauce and for raw broccoli without any heating. SUBSTITUTE SHEET Figure 13 is a pictorial illustration showing the pounds force per gram necessary to shear bread in an Instron machine for bread heated using a system with and without gravy as a shielding layer. This graph illustrates the increased toughening of bread for a system without a gravy shield. Figure 14 is a graph illustrating a functional relationship between temperature differential (between shortcake and whipped cream) and microwave heating time with one system having an intermediate layer of strawberry sauce and another system having no intermediate filling layer of strawberry sauce. Figure 15 is a graph illustrating a functional relationship between filling temperature and heating time for the same system as that used to generate the data for Figure 14. Figure 16 is a graph showing a functional relationship between shortcake temperature and microwave heating time for a strawberry sauce layer shielded system and for a system without an intermediate shielding layer. Figure 17 is a graph illustrating the whipped cream topping temperature as a function of microwave heating time for a product with a strawberry sauce shield layer and for a product without shielding sauce. This was the same system as that which was used to generate the data for Figures 14, 15, and 16. SUBSTITUTE SHEET Figure 18 is a graph illustrating temperature differential between crust and ice cream as a function of microwave heating time for products with and without apple pie filling between the two layers. Figure 19 is a graph illustrating a functional relationship between the temperature of the apple filling and ice cream for the product used to generate the data in Figure 18. Figure 20 is a graph illustrating average ice cream temperature as a function of heating time for the apple filling and ice cream system. The data was generated using the same product used to generate the data in Figures 18 and 19. Figure 21 is a graph showing functional relationships between ice cream temperatures and heating time for products similar to that in Figure 1 that had different ice cream weights and heated in two different ways, in a microwave oven and sitting in a room at room temperature. Figure 22 is a graph showing a functional relationship between temperature of the shielding sauce layer and microwave heating time for four different thicknesses. SUBSTITUTE SHEET Figure 23 is a three dimensional representation of a mathematical model showing a functional relationship between intermediate layer sauce temperature, sauce thickness, and microwav heating time for a sauce having a free water content of 24% and a multi-component food system as shown in Figure 1 having ice cream and brownie on opposite sides of the shielding layer. Figure 24 is an illustration generally showing a possible functional relationship between tolerance to heat of the shielded component and the amount of microwave energy transmitted through the shielding component(s) which is useful to directionally design multi-component food- systems. Figure 25 is a graph illustrating functional relationships between ice cream temperature and microwave heating time. Line A represents a 314 gram ice cream sample and Line B represents a 100 gram charge of ice cream surrounded on all sides by fudge sauce with a substantially uniform thickness and weighing 444 grams. No metal shielding was used. Figure 26 is a graph showing functional relationships between ice cream temperatures and microwave heating time. Line A represents a 544 gram charge of ice cream. Line B represents a 314 gram charge of ice cream and Line C represents a 100 gram charge of ice cream surrounded with a substantially uniform thickness of fudge sauce weighing 444 grams. No metal shielding was used. SUBSTITUTE SHEET Figure 27 is a side sectional view of a container similar to that shown in Figure 1 containing another form of the present invention. Figure 28 is a side sectional view of a multi-component food product in a package showing a still further form of the present invention and is similar to that form used in Figures 25 and 26, an entirely food enrobed food product. Figure 29 is a side sectional view of another food product having a control layer inside. Figure 30 is a graph showing functional relationships between ice cream temperature and microwave heating time for ice cream in an unshielded container, one of the products was enrobed in a layer of sauce. Figure 31 is sectional view of a container. Figure 32 is a graph showing functional relationships between relative heating rate and distance from the top of a food system for a fudge sauce in an aluminum pan (Example 5). Figure 33 is a graph showing functional relationships between relative heating rate and distance from the top for a fudge sauce in a plastic pan as described in Example 5. SUBSTITUTE SHEET Figure 34 is a graph showing functional relationships between relative heating rate and distance from the top of a food system as described in Example 6. Figure 35 is a graph showing functional relationships between relative heating rate and distance from the top for a food system as described in Example 7. Figure 36 is a graph showing functional relationships between relative heating rate and distance from the top for a food system as described in Example 8. Figure 37 is a graph showing a functional relationship between relative heating rate and distance from the top for a food system as described in Example 9 wherein fish is positioned between two pieces of bread. Figure 38 is a graph showing a functional relationship between relative heating rate and distance from the top for a food system as described in Example 9 wherein fish is placed on top of two pieces of bread. Figure 39 is a graph showing functional relationships between relative heating rates and distance from the top for a food system as described in Example 10 wherein ham is positioned between two pieces of bread. SUBSTITUTE SHEET Figure 40 is a graph showing functional relationships between relative heating rate and distance from the top for a food system as described in Example 10 wherein fish is positioned between two pieces of bread. Figures 1A, B, C and D are graphs showing a functional relationship between percent power absorbtion for each layer in a system as a function of the thickness of one layer in the system which is varied. In this figure, the following relative complex dielectric constants were used: oil (2.6-i0.147); water (76.5-ill.l)r and bread (2.8S-i0.75). Figures 42A, B and C are graphs showing, respectively, the functional relationship between power absorbtion and layer thickness, the first derivative of power absorbtion vs. thickness, and the absolute value of the first derivative of power absorbtion vs. thickness. Figure 42A was calculated from equation 3 with E* - 5 and E" - 1- Detailed Description The physics of microwaves in a food system is extremely complicated and-' little is known about how microwave heating in foods is accomplished. The complication, in large part, could be due to the fact that food systems themselves are extremely complicated, SUBSTITUTE SHEET presenting many looks to the microwave field. Such things as preferential heating, the differing chemical natures of foods, nonhomogeneity, the varying locations that discreet food items with different microwave characteristics are positioned next to one another within a single food system, hot and cold spots in an oven, etc. These all complicate the food scientist's and package designer's jobs in designing food products for heating in a microwave oven. In developing the hereinafter described differentially heating food products, certain discoveries were made about the characteristics of the edible components of, these systems which were a surprise. The major surprises were that through property selection one could control how much incident radiation can be shielded by, or how little will be transmitted through, some food components or edible substances and how little effect conductive heat transfer can have in the overall heating of food products within the short time necessary to heat food items in a microwave oven. Other surprises were that: theoretically an increase in thickness in excess of a minimum does not necessarily substantially change the shielding value and a change in thickness above the minimum can simultaneously change absorbance and reflectance oppositely in cycles. As can be seen in Figures 9A, B, and C, absorbance and reflectance cycles with increasing thickness in an opposing manner as thickness increases over small dimensional changes allowing great latitude in product design. The combination SUBSTITUTE SHEET of the low microwave transmission of certain food components and the small role that conduction and other forms of heat transfer can play, provided the basis for achieving controlled differential heating in multi-component food systems, i.e., two or more food or edible components positioned adjacent or proximate to one another. Within a given time of heating in a microwave oven we have been able to achieve predictable and controlled temperatures which were different, say for example, 11°C or more, with some differentials being as high as 65 β C to 80 β C and even as high as 110°C (See Figure 2) over small distances, for example 2 cm. Even more surprising is that the food systems of this invention are tolerant to different ovens and varying heating times. .These tolerances are important for the effective preparation' of the items by consumers. Tolerance is important because of timer variation from oven to oven, the different power outputs of different ovens and because of the hot/cold spot phenomena in ovens. This means that for a given time of exposure, the amount of available energy for heating a food product can significantly vary thereby causing the product to be either overheated or uπderheated. Without tolerance, consumer acceptance of heat sensitive food products could be unacceptably low. Tolerance of products is dependent on the particular product being heated and the consumer concept of quality for that particular product. For example, ice cream, which is very sensitive to heating, has a very small heat tolerance range. Quality ice cream should be stiff or viscous and not soupy. In contrast, soup, which TE SHEET is not sensitive to overheating, would be very tolerant. What is meant by tolerance herein, is that given the above described variabilities in microwave ovens, etc., that a substantial percent of the products after being heated in a microwave oven according to the instructions will have a level of quality acceptable to the consumer. Tolerance can be tested organoleptically which is a standard procedure in the food industry. Figure 1 shows a food system which was a basis for the present invention. Food item or component 1 is a brownie and food item or component 2 is ice cream. It was desired to heat the brownie to a serving temperature of approximately 43 β C-60°C while the ice cream remained "frozen", i.e., at a temperature of approximately -9 β C or colder without appreciable localized melting of the ice cream for example at the interface between the brownie and ice cream. As used herein, unless otherwise designated, frozen means the product is at a temperature of less than 0°C. Container 3 has a shield 4, preferably metal, on the sidewall, extending from the top down to approximately the top surface of the brownie. The top of the container also has a shielding closure or lid 5, preferably metal, to shield incident radiation from the sides and top of the ice cream. The lid S is removably secured to the container 4 and can be glued or heat sealed on and preferably includes a piece of metal foil, for example, aluminum foil, attached to the top of a container i n a manner as is known in the art. The shield or control layer 6 is positioned between the layers 1 and 3. SUBSTITUTE SHEET Figure 27 illustrates another form of the present invention and contains two different edible -products 7 and 8. For example, layer 7 can be a sauce, shielding or control layer positioned inside cup 3. The cup 3 can also have the shield 4 therearound. The lid 5 shields the open end of the cup 3 and, as seen in Figure 1, can be recessed in the cup 3. The layer of product 8 can be, for example, ice cream. The form of the invention shown in Figure 27 can be, for example, a layer of cheese sauce 7 and a layer of broccoli 8 as described hereinafter in one of the examples. Figure 28 shows a still further embodiment of the present •invention which includes a cup 3 having a lid 9 secured to the top thereof in any suitable manner. The lid 9 need not be metal if the shielding or control layer 10 has sufficient shield value. Enrobed within the layer 10 is another edible component 11 which can be, for example, ice cream, and the shield layer 10 can be a sauce. If the shield value of the layer 10 is adequate, then the shield 4 as shown in Figures 1 and 27 need not be added. Figure 29 shows a still further embodiment of the present invention comprising a two-component food product. In this example, the control layer is the layer 14 sandwiched between or encased in edible component 15. In this particular embodiment, the control layer 14 can have its physical properties adjusted as hereinafter described to help control the heating of the exterior layer 15 while SUBSTITUTE SHEET controlling the relative values of its own absorbance and reflectance. In the development of the present invention, a three layer system was initially used, i.e., a layer of brownie, a layer of sauce thereon, and a layer of ice cream on top of the sauce as seen in Figure 1. It was noted that when the layer of sauce was eliminated there was more heating and melting of the ice cream. Then, various control layers were interposed between the brownie and ice cream. It was initially believed that the improved performance from the sauce layer was due to the thermal insulation of the intermediate layer. To test this theory, experiments were conducted using aluminum foil and a silicon, foam insert as the intermediate layer. The results of that type of experimentation are shown in Figure 2. The surprise was that it was not thermal insulation which was making the sauce layer prevent heating of the ice cream, but it was in fact the nontransmission of microwave energy to the ice cream. This is graphically shown by the fact that the highest temperature differential is achieved by a very good conductor of heat and a perfect reflector of microwave energy, i.e., the aluminum foil, while the good insulator and high transmitter of microwave energy, provided one of the lowest temperature differentials. At this same time, the theoretical understanding was being developed which explained the phenomenon of reflectivity and absorbance as functions of thickness and dielectric properties of certain types of food products. SUBSTITUTE SHEET Thus, by interposing an unneeded intermediate edible layer 6 of sauce between the ice cream 2 and the brownie 1, which was initially added only for meeting the definition of the product concept, i.e., a brownie with chocolate sauce and ice cream, the temperature differential between the brownie and ice cream was substantially increased when the properties of that layer were properly selected. The shield or control laye (s) can be defined as an edible layer that affects the microwave irradiation of another edible product or component in the food product, i.e., it is capable of being used for control or it is selected or intended for the purpose of control or is suitable for control. It is to be understood that all components have an effect on the system to some degree. The use of the layer as a shield can provide shielding control of the time/temperature relationship and final temperature of one or more of the components of the system. With the use of the invention, effective heating of the brownie and almost complete elimination of detrimental heating of the ice cream were achieved. It was found that this intermediate layer, if it had a high water content, was very low in transmissivity (high in the sum of absorbance and reflectance) of the incident power thereby acting as an effective edible shield when positioned between the food product to be shielded and the microwave environment. It was also a surprise that the control layer could also enhance heating of the brownie thereby reducing the time of exposure to radiation for a SUBSTITUTE --HEET given brownie size. The invention permits the design and use of new types of microwave products because edible instead of nonedible shields, as in U.S. Patent 4,233,325, can be used. This edible shield in combination with the side and top metal shield, as seen in Figure 1, prevented detrimental heating of the ice cream within the time period required to heat the brownie, thereby improving the performance of the multi-component food system. Thus, this interposed layer is an edible shield which fulfills a long felt need in microwave food heating. Figure 2 shows temperature differentials which graphically illustrate the effectiveness of the present invention compared to a food system with no intermediate layer and an ineffective layer. In order to test the theory of operability of the present invention, certain experiments were conducted. Some of the results are illustrated in Figure 2. A brownie-sauce-ice cream system was used and opposite ends of the spectrum of reflectance and heat transfer were also tested using a brownie-metal foil or silicoπe foam-ice cream system. Line A in Figure 2 shows heating results when an aluminum foil layer was positioned between the brownie and ice cream. This foil, for practical purposes, is a perfect reflector (no transmission or absorbtion) and a perfect conductor of heat. Another experiment utilized an insulating layer, which for practical purposes is a perfect transmitter of microwave energy and SUBSTITUTE SHEET a perfect thermal insulator. The particular layer was a silicone foam. Line E in Figure 2 shows heating results for this foam layer. Figure 2 shows a functional relationship between temperature differential and heating time for a three component system as shown in Figure 1 having a brownie and an ice cream layer with an interposed shielding layer. Temperature differential is the temperature difference between the brownie and the ice cream. The temperatures were taken in four places, two in the brownie 1 cm up from bottom and 2 cm in from the side and two in the ice cream 3 cm up from bottom and 2 cm in from the side with at least 8 runs for each sample with the temperatures being averaged numerically. The sauce had a thickness of 6mm with the high moisture sauce having a free water content, of 37%. (Unless otherwise indicated all component concentrations listed herein are -percents by weight). The normal or control sauce had a free water content of 24%. The foil used was aluminum foil with a thickness of 0.0025 cm and the edges fit tightly against the inside wall of the container. The foam pad was a silicon foam having a thickness of 3mm also fitting tightly against the inside surface of the cup. The no intermediate layer product had the brownie and ice cream in contact with one another. The brownie had a thickness of l. * 7 cm and weighed 42 grams and the ice cream had a butter fat content of 12% by weight, an overrun of 70% and a charge weight of 60 grams. SUBSTITUTE SHEET Figure 2 shows that the lower the transmission of microwave energy, through the use of a reflector like metal foil or higher moisture content sauces, the higher the temperature differential. The foam pad which provided the highest transmission and the best insulation, generally provided the lowest temperature differential showing that it is the transmission of microwave energy which is the primary cause of heating the shielded component. The temperature profile of heating of the foam layer product is Line E, Figure 2. The reversal of the curves for the no intermediate layer and the foam pad at about 80 seconds is probably due to conductive heat transfer showing an effect with time. It can be seen that the aluminum foil, the "perfect" reflector and "perfect" conductor of heat provided the highest temperature differential while the foam, a "perfect" transmitter of microwave energy and "perfect" insulator, provided the lowest temperature dif erential. The prior art had discussed the need for insulators to prevent detrimental heating. Thus the best performance, with regard to temperature differential, being from the best heat conductor and the worst performance being the poor heat conductor was a surprise. These results provide support for the theory that it is control of the transmission of microwave energy in food systems of this type which is the key contributing factor to achieving temperature differential, not thermal insulation which the prior art considered to be required. Thus, a relatively high heat SUBSTITUTE SHEET conductive layer with controlled transmissivity can be effectively used. The theory of operation of the present invention is further illustrated in Figures 9A, B, and C which show curves for reflectance, absorbance, shielding, and related properties of the intermediate layer as a function of layer thickness. The curves are based on calculations. Figure 9A is specific to the control sauce type intermediate layer described above and having the following properties E* * 13 and E" » 3.5 which has a free water content of 24%. Figures 9B and 9C utilize different E' and E" values for comparison and would represent layers with- increased water contents. The locations and intensities of the maxima and minima on these types of curves are dependent on the dielectric properties of the layer material. The disposition of microwave energy in the product in Figure 1 can be approximately defined by the theoretical relationships in Figures 9A, B, and C. For example, the amount of microwave power that is delivered to the brownie is largely dependent on the amount of power reflected by the intermediate layer. However, the amount of power that is delivered to the ice cream is largely dependent on both the amount of power reflected by and absorbed in the intermediate layer. Thus, by addition of the amount of power reflected by and absorbed in the intermediate layer, it is possible to determine the amount of power that has been shielded by the ' UTS SHEET intermediate layer as shown in Figures 9A, B, and C. The relative heating rate of the intermediate layer which was calculated from the absorbance and thermal load of the layer is also displayed in Figures 9A, B, and C. It is apparent that the e fectiveness of the layer as a shield can remain high through a wide range of thicknesses, but its absorbing and reflecting properties and subsequently its ability to heat can vary significantly with a change in thickness. In general, an increase or decrease in absorbance or reflectance results in a decrease or increase, respectively, in the other. The relationships described in Figures 9A, B, and C show that food materials can act the same as other shielding boundaries and differently because it can also absorb, thereby allowing the achievement of temperature di ferentials and differential heating as desired in the product in Figure 1 or the achievement of other beneficial dispositions of microwave power within a food product in an effective and controlled manner. Another test of the theory of operability of the present invention involved the measurement of the temperature differential between the brownie and the ice cream as a function of intermediate layer thickness. To understand the results one should review Figure 9A, a theoretical series of curves based on a layer having E' - 13 and E" * 3.5. This figure indicates that the percent of power reflected by the intermediate layer should rise from zero to a maxima and then fall to a minima between layer thicknesses of 0 cm SUBSTITUTE SHEET and about 1.6 cm. The power reflected by the intermediate layer helps heat the brownie in Figure 1 and also helps shield the ice cream, thereby, exerting a major effect on the temperature differential between he two components. Figure 7 illustrates the results of experimentation varying intermediate layer thickness of the brownie-sauce-ice cream system between 0 cm and 1.6 cm. On the three dimensional graphical representation, Figure 8, temperature differential is plotted as a function of both layer thickness (mm) and microwave preparation time (P, seconds). It is observed that the curve of this plane in space shows a strong relationship to the shape of the reflectance curve of Figure 9A. Thus, the theory and the practical application of that theory are in good agreement. Another test of the theory of operability of the present invention involved the measurement of intermediate layer temperatures as a function of intermediate layer thickness. As illustrated in Figure 9A, the relative heating rate of the intermediate layer is highest at very low thicknesses, falls to a minimum and then rises to a maximum at about 1.6 cm. Figure 22 illustrates the results of experimentation measuring the sauce temperatures of the brownie-sauce-ice cream system at sauce thicknesses between 0.4 cm and 1.6 cm. As can be seen from this data the heating rate is highest at 0.4 cm (temperature in still lower sauce thicknesses cannot be accurately measured with a Luxtron τnodel 750 fluoroptic thermometric system), slightly lower at 0.8 cm, lowest at 1.2 cm and then higher again at 1.6 cm. A mathematical StiBST .T irn: S KHT model of sauce temperature as functions of sauce thickness and microwave preparation time was prepared using this data. The three dimensional representation of this model is illustrated in Figure 23. It is observed that the curve of this plane in space shows a strong relationship to the relative heating rate curve of Figure 9A. Thus, again, the theory and the practical application of that theory are in good agreement. By properly selecting, either by calculation or empirically, the thermal loads of the two main components of the system in combination with proper microwave characteristics of the shield layer effective differential-heating can be achieved in a three or more component system. Further, work has also indicated that in a two component system, one component with properly selected properties can also be effectively used to shield the other component to achieve differential heating. For example, this might take the form of cheese sauce and broccoli wherein the broccoli can be on top of the cheese sauce. The cheese sauce can be heated and also act as a shield to prevent the broccoli from objectionable heating or overcooking. The time necessary to heat such systems also needs to be controlled in relation to the physical characteristics of the food system components. By selecting the relative thermal loads of the components in the multi-component system, the dielectric properties (e.g., E' and SUBSTITUTE SHEET E") and geometries of the components of the system, it is possible to reliably control the absorbance, reflectance, transmission, and shielding ability of them and subsequently reliably control the disposition of microwave power in a multi-component food system. Geometry has an effect on the system. For example, the physical dimensions of, the shape of and the relative positions of the components play a part. These can be selected empirically or through experimentation. It is , re erred that the shield layer be generally the same shape as the surface it is in contact with, i.e., it coincides with the shape of the edible components adjacent thereto. The series of curves illustrated in Figures 9A, B, and C indicate the dependency of the absorbance, reflectance, shielding ability (absorbance plus reflectance), and layer heating rate on the dielectric constant (E*) and dielectric loss factor (E") with varying layer thicknesses. Figure 9A represents the relationships for the chocolate sauce described above as calculated from a mathematical model of that chocolate sauce layer (24% free water) suspended in space. This sauce is believed to have values of 13.0 and 3.5 for E' and E", respectively at room temperature. As the values of E' and E" increase in Figures 9A, B, and C, the intensities (amplitudes) of all the peaks on similar plots increase while the wavelength of the generally sinusoidal curves decreases. This is illustrated in Figure 9B which is projected for an SUBSTITUTE SHEET intermediate layer with the following dielectric properties of E' _> 26.0 and E" - 7.0. Further increases in these values to E* » 39.0 and E" * 10.5 yield the relationships illustrated in Figure 9C with even higher intensities and lower wavelengths. Consequently, by controlling the thickness and dielectric properties of the intermediate layer it is possible to control the reflectance, absorbance, shielding ability, and heating rate of that layer and vary reflectance and absorbance several times over a wide range of thicknesses above a minimum thickness. This permits the design of numerous products having acceptable performance at different thicknesses. It is also possible to use the above described relationships to design even single component food products to heat in accordance with the same criteria set forth for the multi-component systems. In addition to controlling the functionality of the active or shield (intermediate) layer one should also consider the properties of the materials (layers) adjacent the active layer. For example, the shielding ability of the intermediate layer can be varied as described above to optimize the shielding effect but the microwave and thermal loads of the component being shielded, and other components as well, should also be considered. If the sauce in the example discussed remains constant and is shielding about 80% of the incident microwave power as is suggested in Figure 9A, the remaining 20% transmitted through the layer will have a greater effect on SUBSTITUTE SHEET raising the temperature of a small amoun of ice cream than it will on a large amount just due to the thermal load of the ice cream. This is illustrated in Figure 21 which shows the effect of the amount of ice cream being shielded with a constant intermediate layer. It can be observed that the small amount of shielded ice cream heats up more rapidly than higher amounts of shielded ice cream. Therefore, one should first consider the relationships identified in Figures 9A, B, and C to optimize the desired property (i.e., reflectance, absorbance, heating rate, and/or shielding ability) of the-active (intermediate) layer. One should then consider the effects of the materials in close proximity to the active ' layer as seen in Figure 21. It is likely, in certain cases, such as small single serving type products, say 200 grams or less, where the thermal and microwave loads are small r that these factors will not combine to yield a satisfactory product. If this occurs, the use of packaging shields and/or absorbers, as part of the total product may be required. As seen in Figures 10, 11, 21, 25, and 26, the importance of relative thermal load and the need for shielding in low thermal load products are graphically illustrated. SUBSTITUTE SHEET Performance estimates can also be calculated for systems with and without shielding. This was done for a a 5 cm. cube of ice cream with an assumed E' value of 3 and an E" value of 0.8 and 100% overrun. The time to half-melt the ice cream in a cube form was calculated for differing shielding arrangements. Energy required to half-melt the ice cream of 62.5 grams was 336 calories by calculation which in a 700 watt oven will half-melt in about 26 seconds if unshielded. This can be calculated by the equations: P/ - 2ιrE 0 fB- | E r _ ||β | 2 (1 ) T -. Q/P ( 2) Where: P - » Power V a Volume of product E * Electric field strength rms ' f M Frequency E" a. Dielectric loss E m Permittivity of free space T * Time required to half-melt Q » Heat required to half-melt Based on theory, if the product is shielded on all but one side and is in the form of a cube so that all sides are of equal area, incident power on the ice cream is 1/6 of the unshielded cube case which by calculation would take about 2-1/2 minutes to half-melt. If the open side of the shield has positioned therein, a shielding SUBSTITUTE SHEET sauce layer with 60% reflection and 20% absorbance by the shield layer, time to reach half-melt would be approximately six minutes and thirty seconds. However, if one assumes a shielding layer with dielectric properties characteristics of butter 0.8 cm thick having a reflectance of about 25% and an absorbance of about 10%, then the time to half-melt, by calculation, would be about three and a half minutes, i.e., not much different than the unshielded version. It is seen that the shielded cube decreases the incident microwave power by about 5/6. In addition a poor reflecting layer (e.g., butter with 25% reflection) in the shielded cube (packaging shields on the sides and top) will only be about 53% as effective as _ the high reflectance sauce product at shielding the ice cream (i.e., melts in 53% of the time). The same amount of ice cream totally unshielded will be 7% as effective and the ice cream in the shielded cube without a sauce layer will be about 40% as effective as the system with a high reflectance sauce. This calculation shows that proper selection of control layer thickness and dielectric properties in combination can be used to practice the invention. In the practice of the present invention a determination which needs to be made is the desired temperature or heating differential. Another determination which needs to be made is how the product will be distributed. Will it be distributed frozen, refrigerated or shelf stable, i.e., the starting temperature of the SUBSTlTUTi. SHEET product needs to be known. More importantly, the properties of the product just prior to exposure to microwave radiation should be known to properly design the product. Generally a product will be microwaved directly from storage and the storage conditions will be the starting condition of the product. However, a product may be stored at -10*C but heated after a thaw or preheating period. The microwave properties could be substantially different at these different temperatures. Thus, the properties of the product as hereinafter described are those just prior to the product being exposed to microwave radiation for consumption. This would be after preheating, thawing, etc. either in the microwave, after holding at an elevated temperature or the like. Usually it is the final and , major exposure to microwave radiation that prepares the product for consumption that is the condition for which the product is designed. By selecting the relative thermal loads, adjusting the dielectric properties of the components of the food 'system, the reflectance, absorbance and transmission of the shielding component and the time necessary to heat the portion which should be hotter or require more heat input, the desired differential can be reliably achieved. In order to practice the present invention effectively, the shielding layer should be immiscible with the other layer(s) in contact therewith. Immiscible means that the two layers remain substantially separate or distinct having a substantially distinct SUBSTITUTE SHEET interface between the two layers. Immiscibility can be achieved by the control of the properties of each of the layers or can also be provided by a barrier film between the two layers which is also preferably edible. What- is believed to be important is not a complete separation of the layers over time, but the provision of a sharp change or break in dielectric properties (E* and/or E") at the interface between the two layers. Preferably the layers remain immiscible, at least initially during exposure to microwave radiation. Also, the shielding layer should be high in water because 1) water is inexpensive, and 2) water is a very effective and edible shield and has easily variable dielectric properties by the addition of viscosifiers and other soluble materials. The water should preferably be honfrozen, i.e., in this case not in the ice or crystalline form even when it is at a temperature below 0°C; Ice content can be easily affected by the addition of freezing point depressants such as sugars, salt, etc. Also, by adding sufficient viscosifiers such as starch, gums or sugars or others, it could easily be made immiscible with a host of other food product layers and by binding the water effectively with the additives there will be little moisture migration during storage and can be stored over a wide range of temperatures without losing its immiscibility. An edible barrier can also be interposed between two layers to provide immiscibility if less viscous or higher water layers are desired. SύBSflTUTE SHEHT As seen in Figures 9A, B, and C, by changing the dielectric properties of the shielding layer, which can be easily done by changing the free water content, the functionality of the shield can be easily adjusted. As seen in Figure 24, if the shielded product is less tolerant to heat take-up or temperature increase, e.g., small thermal load or degraded by a small increase in temperature or heat uptake, then more shielding is required. Conversely, if the product is more tolerant to heat uptake or temperature increase, then less shielding is required. The tolerance to heat of the shielded product is dependent upon its dielectric properties, its thermal mass and also its sensory attributes. The amount of shielding can be varied as discussed above by varying the makeup of the shielding layer and also by using in combination therewith metal shielding or other shields. As seen from the disclosure herein, the smaller the food item that is to be shielded, generally the more incident radiation which needs to be shielded from the product particularly when it is not very tolerant to heat uptake as for example ice cream. It is believed important that the boundary between the food component layers be distinct, i.e., provide an abrupt change in impedance at layer boundaries, in order to consistently achieve a desired profile of microwave power deposition within the multi-component food product. Air gaps may occur between food SUBSTITUTE SHEET component layers, and it is within the scope of this invention to adjust air gap thickness(es) , or eliminate said gap(s), to achieve a desired profile of microwave power deposition within the multi-component food product. From reviewing the graphs of 5 Figures 9A, B and C and Figures 41A, B and C, it is seen, particularly for products with high E' and E" values that portions of the power absorbtion curves have very steep slopes as they relate to a change in a particular layer thickness. Thus, desirably, in using Figures 9A, B and C, the layer thickness is 0 chosen at about or beyond the peak of the initial incline so that minor variations in thickness do not adversely affect the amount of transmitted microwave energy particularly for systems- intolerant to heat uptake. This peak or change in slope of the shield value curve can be approximated by the first point of inflection of the first & derivative of the shielded power curve. For example, in Figure 9A, the first point of inflection occurs near 80%. Also, the required thickness of this layer can be changed by varying the dielectric properties of the layer and achieve the same shield value. 0 Further, in reviewing Figures 41A B and C, desirably, layer thicknesses are chosen at about a zero or near a local minimum in the curve relating the absolute value of the first derivative of the power absorbtion curve so that minor variations in layer thickness or composition do not adversely affect the amount of absorbed 5 microwave energy, particularly for systems intolerant to heat SUBSTITUTE SHEET uptake. Typically, this occurs at about a local maximum or a local minimum in the power absorbtion curve. For example, in Figure 41A, desirably, the water layer thickness would be approximately 0.4 cm, 0.75 cm, or 1.10 cm, etc., since these thicknesses produce local minima or maxima in the layer power absorbtion and would best enable one to achieve heating rate control. Figure 41B, illustrates a case where, for bread thicknesses below 2.5 cm, the power absorbtion curves have no local maximum or local minimum; a local power absorbtion minimum occurs for water near 3.2 cm and a local minimum occurs for oil near 3.9 cm. Figure 42C shows the absolute value of the first derivative of the power absorbtion curve in Figure 42A. A local minimum in the absolute value of the first derivative of the power absorbtion curve occurs at a thickness of approximately 0.9 cm to 1.0 cm, and zeros in the absolute value of the first derivative of the power absorbtion curve occur at thicknesses near 3.0 cm and 3.8 cm. For the case depicted in Figures 42A, B and C, heating rate control would be more easily attained at thicknesses near 0.9 cm to 1.0 cm, 3.0 cm and 3.8 cm than, for example, near thicknesses of 2.3 cm or 4.8 cm. Also, the optimum thickness of this layer can be changed by varying the dielectric properties of the layers in the multi-component food system to achieve substantially the same result. Thus, one can see that a multi-component layered food system can be easily manufactured to attain a desired power deposition profile within the food system. SUBSTITUTE SHEET As described above the shield layer is used to control the amount of energy transmitted to the shielded component. Preferably the shielding layer has thickness such that the shield value (absorbance plus reflectance) just prior to exposure to microwave radiation for consumption is at least about 70%, preferably at least about 80%, and most preferably at least about 90% of the first point of inflection of the shielding power versus thickness curve. These values are determinable by calculation using the following equation to produce a shielding value curve as hereinafter described in reference to determining absorbance aad reflectance values. Based on theory and assuming a layer in free space, absorbance, transmission and reflectance can be- calculated-by Equation 3. SUBSTITUTE SHEET A - 1 - Jt| a - |r|* where: and Where: A » Fraction of absorbed power d -t Thickness e » Base of natural log i _- v^T k - Extinction coefficient π » Refractive index r at Reflected electric field intensity t » Transmitted electric field intensity \o _t Wavelength =» 12.24 cm § 2450 megahertz n - ik _- VT2' - iE"' SUBSTITUTE SHEET The terms absorbance, reflectance and transmission as used herein are defined as follows: absorbance (A) is that part of the incident power that is absorbed, reflectance frf is that part of the incident power that is reflected and transmission | ■ t| ■ ' is that part of the power transmitted through the product or layer. This equation is graphically illustrated in Figures 9A, B, and C The formula is based on the product being a layer in free space at 2450 megahertz and can probably be improved for accuracy to include layers not in free space. Transmission and reflectance can also be measured by a Genesys Machine (manufactured by Gerling Laboratories) or a Hewlett Packard 8753A network analyzer. Further, preferably the shielding layer has a substantial amount of water. Also, preferably, this water should be free water and unfrozen at the storage temperature or temperature of the product just prior to heating in the microwave oven. Preferably, the free water content be in the range of between about 20% and about 95%, preferably in the range of between about 24% and about 90%, and most preferably in the range of between about 27% and about 85% by weight of shielding layer just prior to exposure to radiation. This free water level can be measured by the procedure set forth in AOAC (methods of analysis) 14th edition, 1984 section 31.118 using an air oven and exposing the sample to 70*C for 16 hours under a pressure SUBSTITUTE SHEET of less than 50mm HG. Preferably, the shielding component should have less than about 50% ice, preferably less than about 30% ice, and most preferably less than about 10% ice by weight of said component as measured just prior to exposure to radiation. Ice content can be measured by differential scanning calorimetry. The amount of free water and ice can be easily adjusted by controlling the additives to this layer, as described above, which can function as freezing point depressants as well as viscosifiers if desired. If the water in the shielding layer is ice, its ability to shield is substantially reduced, but could be utilized in systems requiring little shielding. Also, it is to be understood that ' the shielding layer as described above can be in multiple layers and can also be nonhomogeneous for example it could contain particulate material. With the described values for the layer applying to the composite layers as well. An example of this would be a sundae with both a chocolate sauce and a caramel sauce positioned adjacent to one another and forming a shield around, for example, ice cream. The shielding or control layer has thickness and dielectric properties such that of the incident microwave power impinging from the oven side on the exposed, direct or indirect, major surface thereof about 20% to about 90%, preferably about 25% to about 80% SUBSTITUTE SHEET and more preferably about 30% to about 80% of the incident power is reflected and about 10% to about 65%, preferably about 15% to about 65% and more preferably about 20% to about 65% of the incident power is absorbed and preferably the sum of reflected and absorbed power for shielding or control exceeds about 60% more preferably about 70% and most preferably about 80%. These values for absorbance and reflectance and also for transmission and shielding (as well as the first point of inflection as disclosed above) as disclosed in the specification and as used in the claims (except as noted below for a composite layer) are determined for a single layer by calculation from the above equation A » 1 - |t| - fr| - > E* and E" can be measured with a network analyzer, such as a Hewlett Packard network analyzer. By using the E' and E" values in the equation absorbance, reflectance, transmission and shielding can be calculated. E* and E" and hence the absorbance, reflectance, transmission and shielding values are for the product at a temperature the same as that at which the product would be just prior to exposure to microwave radiation for consumption. For a multiple layer "layer" absorbance, reflectance, transmission and shielding can be measured or determined for the composite using a coaxial wave guide at the subject temperature as just described. The shielding value is the numerical sum of reflectance and absorbance values or 1.0 minus transmission. SUBSTΪT t f*_- SHEET The thickness of the shielding layer is selected to exceed a minimum thickness preferably above about 0.25 cm more preferably above about 0.4 cm and most preferably above about 0.5 cm. The thickness of the layer can be nonuniform and it is preferred that a major portion, preferably at least about 75% and more preferably at least about 90% and most preferably all, on an area basis, is in excess of these values. It can be seen from Figures 9A, B, and C that a thickness in excess of a minimum in practicality will only slightly change the amount of the shielding ability or value of the shielding layer. However, it can be seen from the curves denoted reflectance and absorbance that a further increase in the thickness can change the relative amounts -of absorbance and reflectance allowing fine tuning of the time/temperature relationship for heating during exposure to microwave radiation. This allows for the design of food products to achieve adequate shielding while being able to adjust the temperature of the shielding layer and outer layer(s) without signif cantly or substantially changing the shielding ability of the shield layer. The above values are based on a microwave frequency of 2,450 megahertz. These values will change as the frequency changes. The most utilized frequency for operation of home microwave ovens is 2,450 megahertz and an industrially used microwave frequency is 915 megahertz. Thus, if the frequency changes the mode of control is the same but the values for thickness, dielectric properties. SUBSTITUTE SHEET absorbance, transmission and reflectance will change but are accommodatable with the theory and equations. When viewing layered food systems from xhe perspective of * multi-layer interference effects, it is the system that effects control of each of the edible layers. Power disposition (deposition) or absorbtion in a layer is controlled by the components of the food system. As used herein, food system includes the microwave oven cavity components, e.g, shelf, metal floor, air ,0 gap therebetween, packaging components, if any, , utensils, if any, heaters, if any, the food layers or components, etc. Thus, if a layer needs little or no power or a lot of power this can be accomplished by manipulation of one or more of the food system components to provide controlled heating. The layered food systera- 5 approach is described hereinafter. The heating of any food system or product, including microwave heating, is dynamic and temperature varies with time and location in the product. This is particularly true with microwave heating 0 because of the changing dielectric properties of the product as its temperature changes. Heating results in temperature gradients within each of the components and from component to component in a system. Further, because of the nonuniforraity of microwave heating of a food product it can have hot and cold spots within the product. Therefore, it is difficult to define a microwave heated SUBSTITUTE SHEET product by its temperature because of the variability of the temperature within such a noπuπiformly heated product. Temperature can be measured at various locations within a product to determine , an appropriate time/temperature relationship and would normally be done on an empirical basis after determining the proper location and number of the temperature probes. This type of data can be correlated to consumer testing of the product. However, the desired end result of heating is the perception by the consumer of the product temperature or temperature differential and/or the degree of cooking, e.g., overcooked or undercooked. The time/temperature-relationship of the product during heating determines both the final temperature and the degree of cooking, i.e., the total heat or energy uptake. Consumer perception of temperature and degree of cooking can be tested organoleptically, for example, too hot, too cold, overcooked or undercooked. In fact, actual temperature is not necessarily the relevant criteria, but the perception of temperature, for example, two ice creams which are at the same temperature can be consumed, but the sensation of 20 temperature to a consumer i.s di.fferent. This can be caused, e.g., by the differing ice contents of the products, i.e., a high ice content product can be perceived as very cold when in fact it has % the same temperature as a lower ice product. 25 SUBSTITUTE SHEET A time/temperature relationship can be measured by temperature probes at given locations which can give a representative but incomplete indication of the dynamics of the system at predetermined locations. Such testing can indicate proper or improper heating. However, the final temperature of the product is better measured organoleptically. Thus, within the desired time range of heating, the product should not be overcooked or undercooked and should not become overly hot or stay too cold from an organoleptic standpoint or one product should not heat faster than another product, whereby, the consumer perceives the resulting product as not being properly heated. Preparation instructions can be devised by both organoleptic testing anά temperature measurement systems for different wattage ovens to determine the appropriate time range and time/temperature relationship generally required to achieve an acceptable end product, i.e., within a temperature range for consumption. Heating of a product is done within a predetermined or selected time/temperature relationship range and the final product temperature should be within a predetermined or selected temperature range. The final temperature can be that desired for consumption or the product can cool from the final temperature or equilibrate before consumption. The ranges are predetermined or selected by evaluating the heated or cooked product(s) for ensuring adequate heating, to provide an acceptably cooked and/or appropriate temperature for consumption. SUBSTITUTE SHHET It can also be seen from Figures 9A, B, and C that there are several ways to design a product to achieve similar desired end results for a given product. If one needs to preselect the dielectric properties or the free water level because of product constraints, then an adjustment in the thickness of the shielding layer above a minimum thickness will vary the heating characteristics or time/temperature relationship as described above. It should be noted, according to theory, that absorbed power initially increases with an increase in thickness but quickly reaches a relatively flat response, i.e., a further increase does not substantially increase or decrease absorbance. Thereafter, further increases can substantially increase or decrease absorbance. Thus, with a given sauce, i.e., dielectric properties or free water level, the thickness can be varied to control the heating characteristics or time/temperature relationship. It would be preferred to preselect a range or ranges of thicknesses such that a change in thickness results in a relatively small increase or decrease or change in absorbance and reflectance values so that the thickness is not critical. If the layer thickness is a constraint, then the dielectric properties or free water level can be adjusted to achieve the same control over the heating characteristics of the shielding sauce layer. Another aspect of utilizing the invention is that the dielectric properties or free water level can be determined to be within predetermined ranges and also, the thickness can be predetermined to be within a predetermined range. Then, both the thickness and dielectric properties or free water level can be varied within these ranges to achieve the proper heating characteristics or time/temperature relationships during heating. Even more significantly, in making a three-layer product, for example, the brownie, sauce, and ice cream product, by changing the reflectance of the shield, thereby oppositely changing the absorbance of the shielding layer, the heating characteristics or time/temperature relationship of the brownie can be changed. The reflectance value of the shield can be increased or decreased thereby allowing fine tuning of the heating of the brownie by providing it more or less energy. Thus, it can be seen that the invention herein-provides means for controlling the heating characteristics of one component foods as well the different components of a multi-component food system in an easy manner. The foregoing explanation is based generally on a single-layer edible component positioned in free space. Although this is a good explanation and an effective way to make food products, further work illustrates the unexpected importance of other layers in the food system including those in a microwave oven and the interaction of layers. It has been surprisingly found through a theoretical analysis that all layers, whether part of the food product, package and even the oven should not necessarily be ignored in order to achieve desirable, predictable and/or consistent heating results. The magnitude of the effect of a change in a layer on the layer SUSST . TUI E SHEET itself or other layers in the product in some cases was much larger than expected. A change in one layer affects the heating characteristics of the remaining layers and itself to some degree (in some cases inconsequentially). S When performing this analysis one should include all layers relevant to system heating. The analysis can be done using interference analysis techniques. Since the food product to be heated most often is in proximity to the oven's glass (plastic or ° ceramic) shelf which in turn lies above an air gap and the metal cavity floor, one should include all of these layers along with the food component layer(s) in the analysis, although in some cases the properties of particular layers may prove inconsequential to overall system heating. In general however, one should consider the effects on the food product of layers heretofore believed unimportant to food product heating. Thus, system analysis should include the air layer above the food product or package, the top product or package layer, subsequent product or package layers — including any air gaps, and the glass (plastic or ceramic) shelf, air gap, and metal cavity floor. These are all layers and some, e.g., the metal floor or a metal shield would be considered by some to not have dielectric properties and the computer program will accommodate them as hereinafter described. As used herein all layers of whatever material have thickness and dielectric properties including metal. ..__ :l Extension of the single-layer treatment to multiple layers allows for one or more layers to be adjusted to control the disposition of microwave power within one or more layers in close proximity. The shield or control layers can be defined as one or more layers that affect the microwave power absorbtion, reflection and transmission of one or more edible products or components in the food product, i.e. they are capable of being used for control or they are selected or intended for the purpose of control or are suitable for control. It is understood that all components even oven and food package components, e.g., the metal floor, the shelf, the gap between the floor and shelf, packaging material, metal shields, microwave heater (e.g., that disclosed in. U.S. Patents _ 4,641.005 to Seiferth, 4,230,924 to Brastad et al or 4,267,420 to Brastad) etc. have an effect on the system to some degree. The use of one or more layers as shields can provide shielding control of the time/temperature relationship and final temperature of one or more of the components ' of the system. Due to the fact that the multiple-layer free space treatment is inherently more complex than the single-layer treatment a better means of manipulating the important parameters involved has been devised. In the prior description involving the single-layer treatment, the inflection point of the first derivative of the shielding .power curve of the control layer was used as a means of describing the shield layer's properties. It is more effective to SUBSTITUTE SHEET adjust power absorbtion in the layer or layers and associated desired heating rates of those layers to make a heating controlled food system. It is documented in food science literature that foods vary with respect to their dielectric properties. Dielectric properties are important in describing how microwaves affect a food material. The wavelength of microwaves vary within food products and other materials dependent on their dielectric properties which are dependent on temperature. Microwave power absorbtion is also dependent on the dielectric properties of food products and other materials. When several food or edible materials with different dielectric properties are assembled possibly with other materials in a multi-layered configuration, the microwave radiatioii will change . wavelength and power absorbtion will change as the microwave travels through each of the layers. At the boundaries between the layers reflection can occur diverting some of the microwave back into a layer it has just traversed to be absorbed or transmitted. It will also interact with the incoming microwave to create a standing wave. The standing wave generated in this manner is dependent on the relationship between the phases of the incoming and reflected microwaves. Since microwaves are cyclic in nature the phase of the wave at the point that it interacts is dependent on the distance that the microwave has traversed as well as its wavelength. In the case of a multi-layer food product in an oven this distance is the IUBSTI ΠTEΓ SH ET thickness of the layers. Consequently, microwaves in a multi-layer food product would be in the form of a series of standing waves. The shape of these standing waves and the microwave power that is absorbed from them is dependent on the dielectric properties and thickness of each of the component layers. This invention teaches how the dielectric properties and thicknesses of the component layers of multi-layer food products can be manipulated to obtain desired power absorbtion and subsequently the heating rates in preselected layers. At least one of four parameters should be considered when making a food product with desired power absorbtions in selected component layers. The number of layers, the position of each layer relative to each other layer, the thickness of each layer, and the dielectric properties (relative dielectric constant and' relative dielectric loss factor) of each layer. A first step in practicing the invention is to identify the desired power absorbtion for the food product laye (s) of interest within the product as a whole and in some cases to identify certain layers within which the degree of absorbtion is inconsequential with respect to the overall food product quality. Then one of the layers of interest is tuned to its desired power absorbtion. This is accomplished by manipulating one or more of the four parameters described above for it or one or more of the layers so the ' system beginning with those layers where a preselected power absorbtion is not desired and possibly ending with the layer of interest until the desired power absorbtion is attained. A second layer and subsequent layers of interest can then be tuned in a similar manner. It is very likely that tuning subsequent layers will affect the power absorbtion of layers previously tuned. This is because each layer has an effect, which may vary in intensity, on the power absorbtion of all the layers in the food product. Retuning layers previously tuned is done in a similar manner. Prioritizing layers of interest and identifying or adding layers where preselected power absorbtion is not desired may be done to produce a component food product where the layers of interest have desired power absorbtion. It is understood that dielectrics change with temperature and will therefore change as the food product is subjected to microwave radiation. It is also understood that thickness of layers can change with temperature as in expanding cake batter. For the purposes of this invention, unless otherwise designated, dielectric properties and layer thicknesses are described as those present in the product immediately or just prior to subjecting it to a microwave field for the purposes of preparation. The invention can also be practiced by selecting values for the above-identified four parameters at the end of the heating cycle. An example of a product for which this latter method could be used is a product where SUBSTITUTE SHEET surface crisping is desired. One would want to put a power disposition maximum at the desired time during the heating process at the outer surfaces and perhaps a power minimum in the interior. As discussed above, it is believed important that the boundary between the food component layers be distinct, i.e. provide an abrupt or sharp change in impedance (or relative dielectric constants) at layer boundaries, in order to consistently achieve a desired profile of microwave power deposition within each layer of a multi-component food product. Air gaps may occur between food component layers, and it is within the scope of this invention to also adjust air gap thickness(es) , or eliminate these gap(s), to achieve a desired profile of microwave power deposition within a food product. From reviewing the graphs of Figures 41A, B and C, .it is seen, particularly for products with high E' and E" values that portions of the power absorbtion curves have very steep slopes as they relate to a change in a particular layer thickness. Thus, desirably, layer thicknesses are chosen at about a zero or a minimum in the absolute value of the first derivative of the power absorbtion versus thickness curve so that minor variations in thickness or composition do not adversely affect the amount of absorbed microwave energy, particularly for systems intolerant to heat uptake. Typically, this occurs at about a local maximum or a local minimum in the power absorbtion curve. For example, in Figure 41C, desirably, the water layer thickness would be SUBSTITUTE SHEET approximately 0.4 cm (local minimum), 0.75 cm (local maximum), or 1.10 cm (local minimum), etc. to achieve heating rate control. Figure 9D illustrates a case where the power absorbtion curve has no local maximum or minimum. In this case, a minimum in the absolute value of the first derivative of the power absorbtion occurs at a thickness of approximately 0.9 cm to 1.0 cm. For the case depicted in Figure 9D, heating rate control would be more easily attained at a thickness of approximately 0.9 cm to 1.0 cm than, for example, at thicknesses of 0.2, 0.5, or 1.5 cm. Also, the required thickness of this layer can be changed by varying the dielectric properties of the layers in the multi-component food system to achieve substantially the same result. - Thus, it can- be seen that a multi-component layered food system can be easily made to attain a desired power deposition profile within the food .system. The dimensional tolerance needed of any particular layer within the food product in order to gain heating rate control and thus practice the invention depends on the wavelength of microwaves, for example, at 2.45 GHz, in the layer(s) whose thicknesses may vary. In Figures 41A and 41B the calculated effects of varying the thickness of different layers within a multi-layer system is shown. The program in Appendix A was used to make the calculations relating to Figures 41A, B and C and Figures 42A, B and C. For the purposes of these calculations, a four-layer model system was chosen consisting of a metal pan (bottom), bread,, water and oil (top). The model input parameters are given in the table below. SUBSTITUTE SHEET 56 MODEL INPUT PARAMETERS: Layer ♦ Material Thickness E' E" cp p 4 top Oil 1.90 cm 2.60 0.147 0.4 0.8S 3 Water Varies 76.50 11.100 1.0 1.0 2 Bread Varies 2.85 0.750 0.5 0.15 1 bottom Metal pan 0.05 cm In the case shown in Figure 41A the water layer thickness was varied within the system: MW power -»→ 1.9 cm OIL/0-2.4 cm WATER/4.5 cm BREAD/METAL *→- MW power Figure 41A shows that the percentage power absorbed by oil, bread and water layers all show successive local maxima and minima when plotted against water layer thickness, even though in this series of runs only the water layer thickness was varied. Thus, changes in any one layer can have profound effects on power absorbtion throughout the system. The change in water layer thickness required to move along the power absorbtion vs. thickness curve from any layer's local power absorbtion maximum (or minimum) to that layer's next maximum (or minimum) is very nearly equal to one-half of the microwave wavelength in water. Peak-to-Peak Layer # Material Distance 4 top Oil - 0.681 cm 3 Water 0.703 cm λ/2 • 0.698 cm for WATER 2 Bread 0.696 cm. SUBSTITUTE SHEET In the case shown in Figure 41B the bread layer thickness was varied within the system: MW power -*-* 1.9 cm OIL/1.0 cm WATER/0-10 cm BREAD/METAL «-<- MW power Figure 41B shows that the percentage power absorbed by oil , bread and water layers all show successive local maxima and minima when plotted against bread layer thickness, even though in this series of runs only the bread layer thickness was varied. The change in bread layer thickness required to move along the power absorbtion vs. thickness curve from any layer's local power absorbtion maximum (or minimum) to that layer's next maximum (or minimum) is very nearly equal to one-half of the microwave wavelength in bread. Peak-to-Peak Layer # Material Distance 4 top Oil 3.642 cm 3 Water 3.468 cm λ/2 - 3.595 cm for BREAD 2 Bread 3.584 cm These two runs show that it is possible to predictably control microwave power absorbtion in one layer by adjusting the thickness of that layer or the thickness of another layer within the system. The degree of heating rate control which can be exerted on any layer depends on the thickness, dielectric constant and position of each layer in the entire multi-component system. Thus, Figure 41B shows that, adjusting the bread layer thickness from about 2.5 cm to about SUBSTITUTE SHEET 3.8 cm. can change power absorbtion in the oil layer (layer #4) from about 10.0% to about 8.4% absorbed power, a 16% decrease. Figure 41A however, shows that adjusting the water layer thickness from about 0.75 cm to about 0.5 cm can change power absorbtion in the oil layer from about 4.8% to about 11.6% absorbed power, a 142% increase. In another run, shown in Figure 41C, the water layer thickness was varied within the system: MW power -»→ 3.8 cm OIL/0-2.4 cm WATER/4.S cm BREAD/METAL *— MW power Figure 41C shows that adjusting the water layer thickness from about 0.75 cm to about 0.40 cm can change power absorbtion in the oil layer (layer #4) from about' 7.3% to about 9.4% absorbed power, a 28% increase. This example shows that the degree of heating rate control attainable for any layer within a particular system varies in heretofore unexpected ways and can be surprisingly sensitive to thickness changes to any component in the system. This example can be further analyzed to determine the degree of control over thickness required for each layer of a multi-component food product system in order to attain heating rate control and thus practice the invention. The system will in general be least sensitive to minor thickness variations (and thus most tolerant to SUBSTITUTE SHEET manufacturing processes) when a component thickness is such that the power absorbtion vs. component .thickness curve is at a local maximum or a local minimum. In Figure 41C these local maxima and local minima occur at water layer thicknesses of about 0.40, 0.75, 1.10, 1.45, 1.75 and 2.15 cm. It is well known in mathematics that the local rate of change (the first derivative) of a curve is zero at local maxima and local minima. The system and/or its components should be such that the selected or target thickness of a component has a tolerance of less than about ±2.5% preferably less than about +.5% and more preferably less than about ±7.5% of the wavelength of the microwave in the component at the temperature just prior to exposure to microwave radiation. Likewise, the system and/or its components should be such that the selected or target thickness and "n" as described hereafter approximately obey the inequality of equation 7, preferably approximately equation 6 and more preferably approximately equation 5. Figures 41C and 41B where the water and bread layer thicknesses, respectively, were varied, show that adequate heating rate control is attained when the thickness of each layer in a multi-component system does not vary from its selected target, established or average value by more than about ±7.5% of the microwave wavelength in that layer. Layer thickness can vary across a layer as previously discussed in relation to a discussion of Figures 9A, B and C. The wavelength in any material is a function of frequency and the dielectric constant. At 2.45 GHz, the wavelength in the 8/01476 60 material is given by equation 4. Each edible component or all edible components or any portion of the edible components have thickness at a temperature just prior to exposure to microwave radiation and the variation in the thickness for a substantial number thereof is maintained within this tolerance range of at least one of a selected and an average value of the thickness. This thickness control is for the purpose of maintaining consistent product performance for a substantial number of repetitively made similar products. ,cm » 12.24/n (4) Where: ri _. ' Refractive index of the material, VΕ' - iE"" - n - ik m Microwave wavelength in the material. Better heating rate control is attained when the thickness of each layer in a multi-component system does not vary from its target or established value by more than about ±5% of the microwave wavelength in that layer, and still better heating rate control is attained when the thickness of each layer in a multi-component system does not vary from its target or established value by more than about ±2.5% of the microwave wavelength in that layer. Another aspect of the present invention is the ability to utilize the invention to provide consistent performance results from SUBSTITUTE SHEET product to product. Once a product has been designed and found workable, it is important to ensure that each subsequent similar product or a substantial number of those products, i.e., more than 50% and preferably more than 80% of the products, are similar or substantially identical in performance capability. In general, both layer thicknesses and dielectric constants may vary and suitable control over both of these properties is necessary to achieve heating rate control and practice the invention. The control of thickness and dielectric properties as hereafter described is for the purpose of maintaining consistency of performance of repetitively produced similar products as just described for control of thickness. The dielectric properties 'are those at a temperature just prior to exposure to microwave radiation. Good heating rate control can be attained if the variation in thickness and n, the real part of the square root of the complex dielectric constant as defined above, in each layer approximately obey inequality 5: nΔt * tΔn < (0.075) (12.24) cm (5) Where: t » layer thickness, cm Better heating rate control can be attained if the variation in thickness and dielectric constant in each layer approximately obey inequality 6: nΔt + tΔn < ( 0.05 ) ( 12. 24 ) cm ( 6 ) SUBST1TU TE SHEET Still better heating rate control can be attained if the variation in thickness and dielectric constant in each layer approximately obey inequality 7: 5 nΔt -i- tΔn < (0.025)(12.24) cm (7) If the layer dimensions are fixed the heating rates of the food or edible component(s) can be controlled by manipulating one or more of the dielectric properties of the various food components to „ _ determine their wavelength therein and hence the fraction of 10 incident power absorbed by each component in the system and therefore its heating rate and heating profile within the system. Power absorbtion is shown in Figure 42A. 15 The 1st derivative of Figure 42A is shown in Figure 42B. The absolute value of 1st derivative of Figure 42A is shown in Figure 42C. 20 There are many ways to use the invention herein to achieve desired end results for a multi-layered food product in a microwave oven. There are four fundamental variables that can be manipulated: layer dielectrics, layer thickness, number of layers, and the positions of the layers relative to each other. Layers herein include oven components, package components or other SUBSTITUTE SHEET components in the oven, e.g., cooking utensils. To make a product using the invention herein, these variables can be preselected, selected, varied or not considered. Desired end results include desired heating characteristics of one or more component layers of a multi-layer food product as described by any one or combination of the following measurable responses: heat to within a preselected temperature range or to a temperature within that preselected temperature range; heat within a preselected time range; heat within a preselected temperature range within a preselected time range; heat to a temperature within a preselected temperature range within a preselected time range; have a preselected deposition of power within at least one of the layers of edible components at a time . just prior to exposure to microwave radiation or at a time at the end of exposure to microwave radiation; and/or have a preselected deposition of power within one or more or all of the layers of edible component at a time just prior to exposure to microwave radiation or at the end of exposure to microwave radiation; and/or have one or more of the layers of edible component heat within a desired or preselected time/temperature relationship range. An example of the desired power deposition end result would be the desire to heat on the outer surfaces of a particular layer and not in the center or vice versa. Consequently, there are four fundamental variables and there are fifteen combinations of these four variables (order is unimportant, includes sets of 4, 3, 2 and 1 variables(s)) . If the variables can SUBSTITUTE SHEET be selected (or preselected), varied or not considered the number of possible combinations is eighty-one because this is considered a three-level, f ur-variable, full factorial, statistical design. Some of these combinations would not be useful for the purposes of design (e.g. the combination when all the fundamental variables are not considered). Any one of these variables can be individually selected or changed, or any combination of these four variables can be selected or changed. Responses from a change in one or more variables in one or more layers would be to obtain one or more of the above discussed desired enά results. It has been found that the power deposition profile within food systems can be adjusted in surprising ways by manipulation of component layer thickness or its relative dielectric constant or dielectric properties since E' and E" are coupled. In certain systems the percent of ' incident power . * . absorbed in a particular layer can be changed by nearly a factor of ten by manipulation of component layer thicknesses or dielectric constants. Of course the total number of responses considered expands the possibilities accordingly. By way of example, it might be necessary to preselect the dielectric properties and/or thicknesses of one or more of the layers due to food product and/or oven and/or package constraints and it might be desired to achieve a preselected time/temperature relationship in those layers. It is then possible to vary the dielectrics of the other layers and/or thicknesses of the other layers and/or the positions of the layers and/or the number of SUBSTITUTE SHEET layers to achieve this desired end result. Another application might require a preselected number and position of layers and a desired preselected disposition of power within one of the edible layers. It is then possible to vary the dielectric properties and thicknesses of one or more.or all of the layers to obtain this desired end result. Another application might require preselected dielectric properties of all of the edible layers and a desired average criticality in one or more of the edible layers. It is then possible to vary the thicknesses of layers and/or the number of layers and/or the positions of layers relative to each other to obtain this desired end result. Thus, it can be seen that the invention herein provides many ways of controlling the heating characteristics of preselected layer(s) of a food product containing one or more layers. The making of food systems with desired end results is greatly facilitated using the computer program (Appendix A) contained herein. It is possible to theoretically evaluate many combinations using this computer program and thus avoid an inefficient empirical . . . . approach to obtaining desired end results in multi-layer (or multi-component) microwave food systems. The program allows the use of interference analysis techniques to evaluate or analyze layer effects and change or manipulate responses in one or more layers of the food system and the food product can be changed in accordance with or in response to the output or results of the evaluation. A discussion of interference analysis techniques can be found in SUBSTITUTE SHEET "Dielectrics and Waves". A. R. von Hippel, MIT Press 1954, pp. 5S-60 and "Field Theory of Guided Waves". R. E. Collins, McGraw-Hill Co. 1960, pp. 76-96, the disclosures of which books are incorporated herein by reference. S The included computer program can be used to calculate the local heating rate within a food product/package system without regard to heat or mass transfer. It is written in the ASYST language, available from the Macmillan Software Company and runs on an IBM PC, XT, or AT with at least 512K of memory and an 8087 mathematics coprocessor. The program calculates the local electric field at position x using interference analysis- techniques and then calculates the heating rate at x using equation 2. 1 C (2τr) (2.45 x 10 9 ) (8.854 x lO" 14 ) (E" (x) ) |E rjπs (x) | 2 Xb Q deg C/sec » C8) 4.1868 cp(x)p(x) Where: Erms(x) * Electric field at position x cm, in volts/cm. cp(x) » Heat capacity at x, in cal/gm degree C. p(x) _r Density at x, in gm/ml. E"(x) a Relative dielectric loss factor at position X. 20 Analysis of a food system begins with measurement or estimation of the food component complex dielectric constants, densities, heat capacities, and the physical dimensions for each layer in the system. The data is entered in the model, and if an undesired 25 heating rate profile is obtained, the thickness and dielectric constant of each layer in the system can be varied systematically SUBSTITUTE SHEET until more suitable results are obtained. Usually, layers whose thickness is less critical (for example to the product concept) are varied first. Sometimes, the analysis suggests addition of an air gap, for example, between the bottom product layer and the oven 5 shelf obtained by interposing a cardboard box, whose thickness can be adjusted to optimize the product heating profile. It may be desirable to re-configure the product, for example, by changing the order in which particular food components are layered within the product. In other cases, the addition of a reflective packaging ° element (e.g., of metal) and an air gap of an optimized thickness may be indicated. The program can handle metal thicknesses up to 0.05 cm. Beyond, this thickness, the calculated electric fields beyond the metal S layer become so small that the computer reaches an underflow condition and program execution is halted. Since the overwhelmingly preponderant effect of a "thick" (i.e. thicker than a few hundred angstroms) metal layer is to provide a reflection coefficient near -1.0 (the negative sign arises from the 180° phase change which occurs at the metal surface) the precise metal thickness used in the calculations is unimportant. As described herein, one or more food products (or systems) either in a superposed or layered relationship or in side-by-side relationship or in single layers can be made. The foregoing analytical technique using interference analysis can be used to make SUBSTITUTE SHEET a food product. To accomplish this, one first selects at least one food product and determines a time/temperature relationship range and/or final temperature within a temperature range for said food product to follow or achieve, respectively, during heating in a microwave oven. The performance characteristics, including, e.g., relative heating rate, power deposition and tolerance of the food system, food product or food products are analyzed using the interference analysis techniques. The results of the analysis are used to make an adjustment in at least one of the food products (edible components) whereby the food product (one or more of the edible components) will generally heat within the time/temperature range and reach a temperature generally within the temperature range during microwave heating. As discussed, the food product can be a plurality of food products which can be in superposed- layers. A product is then made by the foregoing method. In the method of making such a food product or products, the edible component(s) has thickness, dielectric properties and position within a microwave oven. One or more of these properties can be adjusted individually or in any combination for the purpose that the edible component(s) will heat within a preselected time/temperature relationship range to a temperature within a preselected temperature range when exposed to microwave radiation. The foregoing interference analysis techniques can be used to analyze the food product or system particularly in relationship to its component' (s) thickness, dielectric properties and/or position SUBSTITUTE SHEET and adjusting one or more of these properties either individually or in combination by applying the results of the analysis. The position, as just described, includes position of the particular component within an oven and/or relative to other edible components. As can be seen, these analysis techniques provide results which can be used to balance the properties of at least one edible component for the purpose of estimating at least one of power and energy distribution within the food product. After a product is made, it can be tested for performance and thereafter further balancing as above described can be done so that the edible component will heat within a preselected time/temperature relationship range and/or t'o a temperature within a preselected temperature range when exposed to microwave radiation. The heating characteristics or time/temperature relationship of the brownie or exposed component can be varied by varying its thickness and/or dielectric properties or free water level. Also, the heating characteristics or time/tempe.rature relationship of the directly exposed component can be varied by varying the thickness and/or dielectric properties or free water level of an indirectly exposed control layer adjacent thereto, i.e., by varying its absorbance and reflectance as described above. Thus, the final brownie temperature can be controlled or adjusted by the control or adjustment of the indirectly exposed control layer's thickness and/or dielectric properties or free water level characteristics. SUBSTITUTE SHEET For example, the brownie can remain relatively cool during heating while the sauce layer can be made to heat to a relatively higher temperature by having high absorbance and low reflectance. The brownie can be heated to a relatively higher temperature and the control layer to a relatively lower temperature by its having high absorbance and low reflectivity- Another product concept that could use this control mechanism could be a filled pastry or brownie or a product where the control layer is inside one or more surrounding products or between two or more products or layers. An evaluation of Figures 9B, D, E, F, and G shows the effect of changing E' and/or E". A decrease in E' dampens the effect of thickness on reflectance, absorbance and shielding if -E" remains generally constant. An increase in E" also dampens the effect of - thickness on reflectance, absorbance and shielding if E* remains generally constant. In particular, the thickness at which successive maxima or minima occur for reflectance and absorbance are increased or decreased by decreasing or increasing, respectively, E'. E' and E" can be adjusted to achieve a desired value for at least one of absorbance and reflectance at a selected thickness so that the food product will heat within a predetermined time/temper ture relationship range when exposed to microwave radiation. Conversely, the E' and/or E" value can be selected and the thickness adjusted to achieve the same performance characteristics. The value of E' and/or E" is preferably adequate to provide an acceptable tolerance for the range of or SUBSTITU TE SHSET 71 variation in product thickness. Thus, the critical nature of thickness can be changed, e.g., reduced, making the manufacture and heating of foods less critical. Another method to control the shape of the reflectance and absorbance curves is to change the value of n and K, respectively the real and imaginary parts of the square root of the complex dielectric permittivity. As n increases, the thicknesses at which successive maxima and minima occur in the absorbance and reflectance curves decrease. As K increases, the intensity difference between successive maxima and minima in the absorbance and reflectance curves decreases. The converse of the above manipulations results in opposite changes. E' and E" can be changed by changing the free water ' level and/or by changing the concentration of and the solutes in the food or edible product or the other, components therein. Typically a change in E' or E" will result in a change in the other but it is possible to effect a much larger change in one than the other. What is meant by direct exposure to microwave radiation is that on first impingement of the radiation, the radiation has not passed through another food product whereas indirect exposure means the radiation has just passed through another food. Passage through or reflection from packaging or oven components does not mean the food is not directly exposed. SUBSTITUTE SHEET It can be seen that in some circumstances one can preselect a thickness of the control layer and vary the dielectric properties or free water level to achieve the appropriate heating characteristics or time/temperature relationship of the shielded product. Also, one can preselect the dielectric properties or free water level and vary the thickness of the control layer to achieve the desired heating characteris ics or time/temperature relationship of the shielded product. Still further, one can have in the product a given control layer thickness and have dielectric properties or free water level selected to achieve desired heating characteristics or time/temperature relationship of the nonshielded or exposed layer or conversely, the control layer can have given dielectric properties or a given free water level and .have thickness selected to achieve the desired heating characteristics or time/temperature relationship of the nonshielded or exposed layer. Still further, in the process of making the product one can select a thickness for the control layer and vary the dielectric properties or free water level to provide the desired heating characteristics or its time/temperature relationship of the control layer or conversely, one can have selected dielectric properties or free water level and vary the thickness to provide the desired heating characteristics or time/temperature relationship of the control layer. Likewise, one can in the process of making the product select thickness and dielectric properties or free water level from within predetermined ranges of values and select values from within the range to provide the desired heating characteristics and/or time/temperature SH ET, SUBSTi Vi " relationship in the same manners just described. Also, in the product one can have a given value of thickness or dielectric properties and free water level from within a predetermined range and have a value for the other selected from within a predetermined range. From the above, it can be seen that the present invention can be utilized in several ways to control the disposition of microwave energy in the different components of the multi-component system. This can be accomplished by varying one or more properties over a wide range providing flexibility in product concepts. A particularly preferred embodiment is that shown in Figure 1 and is described hereinafter. It includes a brownie positioned in the bottom of a shielded cup having a layer of chocolate sauce positioned thereover and in contact therewith and having positioned over the sauce a layer of ice cream in contact with the sauce each contact surface being generally flat. Each layer has a substantially uniform thickness but it is particularly desired for the sauce to have a uniform thickness. The metal shield and the sauce cooperate with one another to substantially completely and preferably completely surround the ice cream to prevent leakage of microwave radiation through gaps between the shielding layer and the metal shield. iUBSTlTUTE SHEET When data were taken for comparison of similar or the same products the temperature probes were located in positions that were believed would provide the most valid and/or reliable data even if they were in different locations in the same or different products. The attempt was to locate the probes in constant positions relative to the geometry of the containers. Figure 3 shows the results of a series of experiments to test a two layer system of ice cream and sauce. The ice cream and sauce are substantially as described for the product used in the Figure 2 experiments. Figure 3 shows the effect of the thickness of the shielding layer on ice cream temperature for various heating times. The graphs shows that for increasing control layer (sauce) thickness, the higher the shielding effect of the shielding component. Further increases in thickness would be expected to increase the shield value but at a reduced rate. The data agrees with the theoretically obtained shield power curve of Figure 9A. Figure 3 was corrected for different starting temperatures to better show the results. When viewing Figure 3 in conjunction with Figure 9A, it is seen that absorbance and reflectance both vary oppositely with increasing thickness with these curves having a somewhat sinusoidal shape. This means that an increase in thickness can both increase and decrease absorbtion and reflection. However, when evaluating the shielded power curve (which is total incident power minus the transmitted power), it is seen, from a practical standpoint, that an increase in thickness results in an increase in shielded power or a decrease in transmitted power with only a slight reversal of that trend after a first thickness peak or maximum. However, this change is of a minor nature and practically is of little consequence. It can be seen from these graphs that with a desired amount of shielded power that the absorbance and reflectance can be changed to change the heating characteristics of the shielding layer, i.e., it can be made to heat more or less by adjusting the dielectric properties of the shielding layer. The theoretical approach of Figure 9A is supported by actual data taken which is illustrated in Figure 3. Figures 4, 5, 6, and 7 illustrate various temperature relationships as functions of microwave heating time for food component systems with and without a shielding layer. The brownie and ice cream components of this system are substantially as those described in the explanation of Figure 2. Figure 2 also includes other than an edible shielding layer, i.e., aluminum foil and silicon foam and also shows the use of two edible shielding layers with different water content. These four figures show the effect of the use of a shielding layer versus a product without a shielding layer and the effect of the amount of shielding provided by the shield layer. The graphs show that the lower the microwave transmissivity the higher the temperature differential. SUBSTITUTE SHEET Figure 8 is a graph illustrating a functional relationship between temperature dif erential, shielding layer thickness and microwave heating time. The graph was generated by calculation using a model constructed with the raw data of Figure 7. The product had a sauce with dielectric properties the same as those used in Figure 9A. Figures 9A, B, and C are families of curves showing the functional relationship between percent of reflected power, absorbed power, shielded power, and relative heating rate as functions of the shielding layer thickness. This was based on calculations using E' values of 13, 26, and 39 and E" values of 3.5,-7.0, and 10.S, respectively. As E* and E" change- the characteristics of the shielding or control effect of the intermediate layer also change,' i.e., as E' and E" increase in value the amplitude of the variables increase and the wavelengths decrease. Higher E* and E" values are for higher free water level sauces. There is currently being sold a microwaveable ice cream sundae called Hot Scoop. It contains a total product weight of 150 grams which comprises approximately 90 grams of ice cream and about 60 grams of sauce. Sauces available are a chocolate sauce, caramel sauce and a mint flavored sauce. Heating experiments were conducted on the chocolate and mint products measuring the ice cream temperature at 2 cm from the sidewall and 1 cm below the sauce layer SUBSTITUTE SHI on top and attempting to measure the sauce temperature at 2 cm from the sidewall through the top cover and into the sauce at a depth of 4mm to 6mm which was difficult in view of the thinness of sauce and the dynamic property of the product when it is heated, e.g., the sauce sinks into the ice cream and the ice cream comes up around the sides when heated. The sauce temperature readings, although taken as well as could be done, are probably not very accurate. The temperature differential between the sauce and the ice cream was calculated from the temperature measurements graphically depicted in Figure 10 as a function of heating time. As shown. Hot Scoop product achieved no measurable temperature difference between the ice cream and sauce indicating that the ice cream and sauce were heating, at least where measured and as measured, at the same rate providing no differential temperature. In contrast, by practicing the present invention, it is seen in Figure 10 that much greater differential heating was achieved. Product against which the Hot Scoop product was tested was in a metal shielded cup as seen in Figure 1 with a total component weight of 134 grams comprising 60 grams of ice cream, 32 grams of sauce, and 42 grams of brownie with the shielding sauce having a thickness of 0.6 cm. Further, it can be seen in Figure 11 that the heating time of the Hot Scoop product is extremely critical while the heating time for the invention product is much more tolerant to heati.ng ti.me vari.ati.ons i.n a mi.crowave oven. Also, the i.nvention SUBSTITUTE SHEET product is designed to substantially prevent movement of the layers, particularly the shield layer, substantially throughout heating. This is accomplished by having generally flat layers or coplaπar layers. 5 To further illustrate the importance of practicing differential heating in accordance with the present invention other experiments were run. Heating experiments were conducted using a container as shown in Figure 1 having a height of 6.03 cm, a bottom diameter of 10 6.98 cm, and a top diameter of the sidewall of 8.46 cm, and a 7° sidewall taper containing ice cream. In the first series of experiments, ice cream was placed in the cup and was coated entirely with a 6mm layer of Mellocream ' sauce. The ice cream was standard ice cream and the Mellocream is a standard fudge sauce available 15 from J. Huπgerford Smith Company. The cup had no shielding label or lid. In these experiments using the Mellocream, the 6mm coating of sauce weighed 120 grams. The- ice cream weighed 50 grams and had a height of 27mm giving a total weight in the cup of 170 grams and a total height of 39mm. Temperature probes were located 18mm in and 20 15mm up, one on each side and 19mm in and 24mm up, one on each side to measure the temperature of the ice cream. Also, the same cup was used and contained 170 grams of ice cream, 60mm high with no sauce. Figure 30 shows the functional relationship between the ice cream temperature and heating time for the sauce (line B) and no sauce 2 S (line A) versions. Both were unsuccessful in retaining the ice SUBSTITUTE SHEET cream quality after heating. There was no significant difference between the heating of the shielded product and the nonshielded ice cream. A similar series of experiments were run using a similar but larger cup with no metal shielding. In this case a 12mm thick fudge shield was used using standard ice cream and standard Mellocream fudge sauce. The cup had a bottom inside diameter of 96mm and a top inside diameter of 106mm and a height of 96mm. The sauce coating was 12mm thick and weighed 444 grams and completely surrounded the ice cream. The ice cream weighed 100 grams and had a height of 36mm providing a total weight of product of 544 grams and a total height of 60mm. Temperature probes were located 20mm in and 22mm up and 20mm' in and 45mm up, one on each side. This product was compared to 314 grams of unshielded ice cream in the same cup. The ice cream had a height of 60mm. Figures 25 and 26 show a functional relationship between temperature and microwave time showing effectiveness of the shielding layer when the thickness and the relative thermal loads are properly selected. Thus, without the proper selection of properties effective shielding is not achieved. To shield an ice cream product such as Hot Scoop only with sauce to prevent melt-down of the ice cream would require substantially more sauce and ice cream than when metal shielding is used. SUBSTITUTE SHEET In some of the following examples using ice cream, brownie and sauces in juxtaposed layers in a plastic cup the following description applies. A preferred embodiment is shown parenthetically for the products and container. The brownie is made from a brownie mix and is baked to about a 14% moisture content. Approximate formula of the brownie mix, by weight of mix, is flour 29.1% (31-0%), enrichment 0.024% (0.026%), sugar 51.8% (55.15%), shortening 7.5% (8.0%), cocoa 0.37% (2-09%), cocoa 1.96% (2.35%), cocoa 2.21% (0.40%) (the three cocoas are different), soda 0.05% (0.054%), salt 0.76% (0.81%), vanilla flavor 0.14% (0.15%), chocolate liquor 6% (0%), and albumin 0.6% (0%). Eggs, oil, (chocolate liquor) and water are added to the mix to form a batter with the approximate formula of the batter, for a dry mix with albumin (egg 5.90%), mix 71% (65.76%), Durkex 100 oil 11-6% (11.45%), (chocolate liquor 4.20%) and water 17.3% (12.70%). It is preferred that the vertical edge of the brownie when in the cup is spaced from the bottom end of the shield 4 at least 3mm when localized heating of the brownie has occurred when positioned closer. . . . A brownie with a thickness of preferably above 0.5 cm, more preferably above 1.0 cm, and most preferably above 1.5 cm. The thickness of the brownie can be non-uniform and it is preferred that a major portion, preferably at least about 75% and more preferably at least 90% and most preferably all, on an area basis, is in excess of these values. The brownie should have a relative dielectric SUBSTITUTE SHEET 81 constant (E') of preferably above 1-0, more preferably above 1.5 and most preferably above 2.0 at -24 C. The brownie should have a relative dielectric loss factor (E") preferably above 0.05, more preferably above 0.10 and most preferably above 0.15 at -24°C. The dielectric properties can be non-uniform throughout the brownie due to heterogeneities and it is preferred that a major portion, preferably at least about 75% and more preferably at least about 90% and most preferably all, on a volume basis, are in excess of these values.. A preferred intermediate layer in this product is a fudge sauce and hereinafter is referred to as a "control sauce" and contains the approximate following percentages by weight of ingredients: Sugar 15.6%, corn syrup 9.2%, high fructose corn syrup 10.3%, sweet condensed milk 30.6%, shortening 8%, cocoa 7%, nonfat dry milk 1%, salt 0.3%, vanilla 0.25%, starch 1.2%, alginate 0.6%, and distilled water 15-87%. Higher moisture sauces vary primarily from this formula by the amount of water therein. Another acceptable sauce is Johnston's Red Label sauce which is commercially available. For flowability, the sauce should have good shear thinning properties. A sauce layer with a thickness of preferably above 0.2 cm, more preferably above, 0.4 cm and most preferably above 0.6 cm. The thickness of the sauce layer can be non-uniform and it is preferred that a major portion, preferably at least about 75%, and more SUBST. Tu £ SHISEΓ preferably 90% and most preferably all, on an area basis in excess of these values. The sauce should have a relative dielectric constant (E') of preferably above 4.0, more preferably above 5.0 and most preferably above 6.0 at -24°C. The sauce should have a relative dielectric loss factor (E") preferably above 0.5, more preferably above 1.5 anό most preferably above 2.5 at -24 β C. The dielectric properties can be non-uniform throughout the sauce due to heterogeneities and it is preferred that a major portion, preferably at least about 75% and more preferably at least about 90% and most preferably all, on a volume basis, are m excess of these values. A preferred ice cream has an overrun of 70%, a butterfat content of approximately 12%, vanilla flavor and a churned out fat content of approximately 1.25%. The fat globule size preferably is about 3" microns to about 10 microns as compared to a normal ice cream which has unchurned fat with a fat globule size of about 1 to 2 microns. It was unexpectedly found that ice cream containing a churned out fat content by weight of ice cream of about 1% to about 2% preferably about 1.2% to about 1.8% most preferably about 1.4% to 1.6% by weight of ice cream was more stable during microwave exposure. Churned out fat means that the fat globule sizes are about 3 microns to about 10 microns in diameter. The reason for improved microwave exposure stability is unclear. Normal ice cream has little or no churned out fat, about 0.3% or less by weight. SUBSTITUTE SHEET An ice cream layer with a thickness of preferably above 0.7 cm, more preferably above, 1.4 cm and most preferably above 2.1 cm. The thickness of the ice cream layer can be non-uniform and it is preferred that a major portion, preferably at least about 75%, and more preferably 90% and most preferably all, on an area basis in excess of these values. The ice cream should have a relative dielectric constant (E 1 ) of preferably below 10.0, more preferably below 8.0 and most preferably below 6.0 at -24°C. The ice cream should have a relative dielectric loss factor (E") preferably below 4.5, more preferably below 3.5 and most preferably below 2.5 at -24 β C. The dielectric properties can be non-uniform throughout the ice cream due to heterogeneities and it is preferred that a major portion, preferably at least about 75% and more preferably at least about 90% and most preferably all, on a volume basis, are in excess of these ' values. An air gap can also be provided between the ice cream and should be between about 1 cm and about 2 cm. A preferred package for single serve products is shown in Figure 1. It has a container 3 wall thickness of 0.15 cm and is made from high density polyethylene with the dimensions as described above. It is preferred that the top 5 be 48 gauge (0.0011 cm) polyethylene of 7 pound low density polyethylene as the outer laminant with a 35 gauge (0.0009 cm) foil laminated thereon with a SUBSTITUTE SHEET 1.5 mil (0.0025 cm) extrudable hot melt as the inner laminant with the foil between the inner and outer laminants. A preferred shielding label 4 material is a 48 gauge (0.0011 cm) polyethylene of 7 pound low density polyethylene material as an outer laminant with a 28 gauge (0.0007 cm) aluminum foil layer laminated between the outer laminant and a 2 mil (0.005 cm) Surlyn inner laminant. A preferred cup 3 diameter is 8.1 cm in diameter when the cup is cylindrical, but if frusto conical it is preferred that the minimum diameter be in the range of 7.0 cm to 8.5 cm inches while the height of the aluminum portion of the label is preferred to be 6.1 cm in height with the two ends electrically connected or spaced apart about 0.32 cm. The immediately above described preferred package was found effective for heating certain food products. The package shown in Figure 31 is another 'preferred package and provides some advantages over the operation of the package shown in Figure 1. The container 20 has a wall 23 thickness of which varies from 0-06 cm to 0.08 cm and is made from high density polyethylene. As the tapered side wall 23 would approximately 7° and outside lip 21 diameter of approximately 9.97 cm- A step 22 outside diameter of approximately 9.6 cm and an outside diameter at the top of the tapered wall 23 of approximately 8.6 cm. The overall height from the bottom of the cup to the top is approximately 6.5 cm, the height of the shelf 24 in the bottom of the package is approximately 6.2 cm. The outside SUBSTI diameter of the bottom 25 is approximately 7.13 cm. The package 20 has a shield label 4 as described above and extends from the bottom of the shelf 24 down toward the bottom of the container 20 has a height of approximately 5.4 cm The bottom edge 26 of the label is spaced from the food product by the gap 27 by a distance of approximately O.S cm. As described above for the container 3, the package 20 has a top 5. The above described shielded cup is particularly good for the prevention of arcing in single size serving containers. The above identified figures which are based on the three component b__rownie-sauce-i.ce cream system or t■h_.e b,.rowni.e and- i.ce cream system utilize the above described brownie sauce and ice cream in a tapered sidewall cup as described. The graphs illustrate the operability of the present invention. Many of the figures presented herein are plots of relative heating rate versus the distance from the top of the system under evaluation. Relative heating rate is calculated for any point on this curve by dividing the actual heating rate at a specific distance from the top by the highest actual heating rate occurring in the entire range of distances evaluated. Thus, the highest SUBSTITUTE SHEET heating rate is given a value of 1.0 and all other heating rates are given values less than 1.0. To show operability of the present invention the following additional examples are provided. Example 1 Experimentation was conducted to demonstrate the shielding effect of a cheese sauce to avoid overcooking of broccoli which is desired to be heated to a serving temperature and retain crispness. Broccoli and cheese sauce were placed in a tapered wall cup with metal shielding on the side and top as described above. The broccoli was heated both with the cheese sauce shield and without a cheese sauce shield. A shear press measurement was used to measure the crispness of the broccoli after heating. The shear press value of raw broccoli and the microwave heated broccoli with no cheese sauce and with cheese sauce was measured with the heating time being about 3 minutes and 30 seconds in a 770 watt oven. Figure 12 shows graphically the effect of the use of a cheese layer shield on the degree of broccoli cooking. The broccoli with the cheese sauce shield was significantly crisper than the nonshielded version which was not crisp, and was only slightly less crisp than a raw . broccoli. Thus, the effectiveness of cheese sauce layer to shield broccoli positioned on top of the cheese sauce is demonstrated. The broccoli was 70% stems and 30% florets cut to 1 cm to 2 cm in length- and 0.8 cm to 1.5 cm in diameter. The cheese sauce had a moisture content of approximately 75.5% by weight of the cheese sauce. The cheese sauce weight was 26 grams and was 6mm in height (thickness). The broccoli weight was 64 grams in the cheese sauce shielded version for a total weight of 90 grams and was microwaved for three minutes and thirty seconds. The unshielded version contained 90 grams of broccoli and was also microwave heated for three minutes and thirty seconds. In the unheated broccoli, 50 grams of broccoli was used. The reduced weight was due to space requirements in the cup. Example 2 A bread and gravy system was used in the above described tapered wall metal shielded cup having a lower layer of gravy with bread on top. This was compared to bread in an identical cup, but using two layers of bread and no gravy. The firmness of the bread was measured after heating in both systems to compare the unshielded to the shielded bread. The bread was a standard white bread cut to fit the inside diameter of the cup and the gravy was Home Style gravy made by H. J. Heinz Company. In the gravy version, 48 grams of gravy with a height of 11mm was used and 10 grams of bread w th a SUBSTITUTE SHEET height of llmra. for a total weight of 58 grams and a total height of 22mm were microwaved for 25 seconds in a 770 watt oven. In the unshielded version, two pieces of bread, both weighing 10 grams and having a height of 11mm, were heated for a combined total of 20 grams of product and a 22mm height and were heated for 25 seconds in the same oven. Figure 13 graphically shows the toughening of the bread which occurs upon further heating with a much higher toughening or pounds force per gram of bread in a system without a shield than with the shield. The testing was done on an Instron machine. A layer of Saran film was interposed between the bread and gravy to prevent moisture migration so that this would not effect the bread toughening testing. Example 3 A strawberry shortcake product was made using a layer of Cool Whip brand topping with a strawberry filling between it and a layer of shortcake which was on the bottom of the tapered wall cup having the metal shielded side and top. This product was compared to a similar product without the strawberry filling between the Cool Whip and shortcake. In the shielded version, the shortcake weighed 28 grams and had a height of 1.8 cm, the filling weight was 60 grams and had a height of 1 cm, the topping had a weight of 25 grams and a height of 2.2 cm for a total weight of 113 grams and a total height iUBSTITO " SHEET of 5 cm. In the unshielded version, the shortcake weighed 28 grams and had a height of 1.8 cm, topping weight of 40 grams, and a height of 3.2 cm for a total weight of 68 grams and a total height of 5 cm. Temperature probes were located 3 cm in and 3.7 cm up and 2 cm in 1 cm up, one on each side. Figures 14 through 17 graphically illustrate the effect of heating on these two different systems and the effectiveness of the shielding effect of the intermediate filling layer. It is interesting to note that Figure 14 shows a relatively flat response curve after the initial increase in temperature differential for the filled version compared to the nonfilled version and that the shortcake temperature shown in Figure 16 generally followed the same curve for both the filled and nonfilled versions. Figure 17 shows topping temperatures illustrating the large increase in temperature of the nonfilled or . nonshielded version as opposed to the shielded version. A review of Figures 14 through 17 indicates that the strawberry filling is acting as an absorber, not a reflector, while still providing shielding. This is indicated by the cake temperature profiles in Figure 16. Example 4 An apple pie a la mode product was made in the shielded tapered wall cup as described above. Product consisted of a 50 gram layer SUBSTITUTE SHEET of ice cream which was positioned over a 20 gram layer of Chef Pierre brand prebaked crumb topping which in turn was positioned over a 110 gram layer of prebaked Chef Pierre apple filling for a shield. This product was compared to 175 grams of ice cream in the same cup. The location of the two temperature probes were 4 cm up and 2 cm in and 1 cm up and 2 cm in, with one on each side at each location. Figures 18 through 20 graphically illustrate the heating responses of the two different products showing the effectiveness of the apple pie filling as a shielding layer. The above examples illustrate that the present invention is an effective and tolerant way of achieving temperature differential in multi-component food systems. It shows that a low temperature differential can be achieved as well very high temperature differentials. The invention provides for the manufacture of many food items which heretofore have not been available for microwave heating. In fact, a brownie and ice cream system could not be differentially heated in any other manner if the two components are packaged together. This is achievable because of the short time required to heat foods in a microwave oven and the use of the shielding layer. SUBSTITUTE SHEET Example 5 ONE LAYER FUDGE SAUCE/METAL OR PLASTIC PAN EXAMPLE Fudge sauce of known dielectrics (E' * 18.00, E"«9.16, temperature » 23°C) was uniformly placed in 9"xl3" pans. One series was run in a aluminum pans (E'-l.O, E"-2-67 x 10 , thickness - .05 cm, heat capacity - 1.2 cal/g deg C, density - 2-7 g/ral) and one series was run in plastic pans (E'»2.2, E"»l-1 x 10 , thickness - 0.175 cm, heat capacity =• .5 cal/g deg C, density * 1.0 g/ml). Each series contained three pans where the sauce was 1 cm thick and three pans where the sauce was 2 cm thick. Four Luxtron temperature measurement probes were placed at a depth of 0.45 cm and four Luxtron temperature measurement probes were placed at a depth of 0.80 cm in close proximity in each pan prior to exposure to microwaves. Heating rates were measured in a microwave oven with a glass shelf (E'»4.05, E"»4.29 x 10~ , thickness - 0.6 cm, heat capacity » 1.0 cal/g deg C, density ■ 1.0 g/ml) and an air gap below the described product system and above the reflective floor of the oven. Average relative heating rates ratios between the two probes depths were calculated from the resultant time/temperature curves. Relative heating rate curves (see Figure 33 for plastic pan cases and Figure 32 for aluminum pan cases) were also obtained using the data described above and using the computer program contained herein. Predicted relative heating rate ratios were calculated from SUBS T ΓΓJTE SHEET the computer generated data. These measured and predicted ratios are presented in the table below: Pan Fudge Sauce Predicted Heatmg Observed Heating Type Thickness Rate Ratio Rate Ratio Metal 1 cm 4.0 1.3 Metal 2 cm 2.0 1.3 Plastic 1 cm 0.4 0.9 Plastic 2 cm 1-1 1.0 Possible causes of differences between predicted and observed values include probe placement, variations in overall sauce layer thickness, and thermal transfer (which is not accounted for by the computer program contained herein).. Example 6 CHEESE/FUDGE SAUCE EXAMPLE The following multi-layer food system was constructed: Heat Capacity Density Layer E « E" Thickness (cal/q deq C) <σ/ml) Sauce 14.9 8.7 Variable 0.65 1.1 Cheese 22.0 18-7 1.00 cm 0.70 1.1 Plastic 2.2 i.ixio "3 0.18 cm 0.50 1.0 Metal 1-0 2-7xl0 8 0.05 cm 0.20 2.7 SUBSTITUTE SHEET Layers of the fudge sauce and the commercially-obtained Velveeta cheese were uniformly placed in six Tupperware pans. The cheese was placed in the bottom of these pans and fudge sauce was placed above the cheese at a thickness of 0.6 cm in three of the pans and 1.0 cm in the other three pans. The bottoms of the pans were covered with aluminum foil. Luxtron temperature probes were located at 0.4 cm from the top surface in the fudge sauce layers in all the samples and in the center of the cheese sauce layer at depths of about 1.2 cm to 1.3 cm from the top surface when the fudge layer was 0.6 cm thick and about 1.6 cm to 1.7 cm from the top surface when the fudge layer was 1.0 cm thick. Temperatures at these probe locations were measured at two second intervals for 40 seconds after exposure to microwave radiation. Heating rates were measured from these curves and the ratios of the heating rates between the probe . locations were calculated. Using the computer program contained herein, predicted heating rates were obtained (see Figure 34) and similar ratios were calculated. Comparisons of predicted and actual values are contained in the following table: Predicted Heating Observed Heating Fudge Sauce Rate Ratio Rate Ratio Thickness Between Probes Between Probes 0.6 cm 1.3 1. .8 1.0 cm 3.0 2..3 Possible causes of difference between predicted and observed heating rate ratios include probe placement, variations in overall layer thicknesses, and thermal transfer (which is not accounted for in the computer program contained herein). 88/01476 94 Example 7 FISH CRISPING EXAMPLE A 3 millimeter thick corrugated cardboard pad (E'-rl.OO, E" * Q.QQ) was placed on the glass- shelf (E'_r4.0, E"«4.0 x 10 , thickness = 0.6 cm, heat capacity - 1.0 cal/g deg C, density » 1.0 g/ml) in a microwave oven. Below the glass shelf was a 0.9 cm air gap above the reflective floor.of the microwave oven. On this pad was placed a susceptor with a surface resistance of about 500 ohms/square. On top of the susceptor was placed a batter-coated fish fillet of varying thickness (E*-»-44.5, E"»10-5, heat capacity * 1.00 cal/g deg C density » 1-00 g/ml). Over the fish was a 3-17 cm air layer (E'-rl.00, E"-0.00) and on top was metallized shield (E'-l.OO, 8 . -2 . • E"=2.67 x 10 , thickness » 5.00 x 10 cm, heat capacity » 1.2 cal/g deg C, density * 2.7 g/ml). Multi-layer systems containing fillet thickness of about 1.30, 1.12, 0.93, and 0-74 were assembled in this manner and subjected to microwave preparation. Crispness of the fillets was measured by a sensory panel on a scale from 0 (not crisp) to 60 (very crisp). The table below summarizes these crispness scores. The computer program contained herein was used to generate predicted heating rates for these four systems as shown in Figure 35. It is observed from this figure that the relative SUBSTITUTE SHEET 95 heating rate within the fish layer varies considerably from being high on the edges and low in the center (as in the 0.74 cm and 0.93 cm samples) to low (as in the 1.12 cm and 1.30 cm samples), and that sample crispness correlated with predicted susceptor heating rate. These predictions are in good agreement with the observed crispness scores. Fillet Thickness Crispness Score 0.74 cm 38 0.93 cm 41 1.12 cm 38 1.30 cm 25 Example 8 THEORETICAL EXAMPLE OF BROWNIE/SAUCE/ICE CREAM/METAL Using the computer program contained herein, predicted heating rate data (see Figure 36) on the following multi-layer system were obtained: Heat Capacity Density Layer E' E" Thickness (cal/q deq C) <o/τπl> Metal 1.0 2.7xl0 8 0.05 cm 1-2 2.7 Ice Cream 5.96 2.5 2.3 cm 4.4 0.6 Sauce 11.9 7.0 Variable 0.6 1.1 Brownie 2.6 4.0x10 " 1.7 cm 0.5 0.7 Shelf 4.0 4.3xl0~ 3 0.6 cm 0.2 2.23 Air 1.0 0.0 0.9 cm 0.24 1-3x10 " " SUBSTITUTE SHEET Fudge sauce thickness was varied from 0.2 cm to 1.0 cm in steps of 0.2. It can be seen from Figure 36 that these small changes in thickness of the sauce layer (denoted by the peaks beginning at about 2.4 cm from the top on the figure) have a large effect on the . average relative heating rates of the ce cream layer (denoted by the peaks at about 1.4 cm from the top). Although the relative heating rate of the brownie (the peaks the farthest from the top) does not appreciably change in these examples, the ratio of the average relative heating rate of the brownie to the average relative heating rate of the sauce or ice cream does vary considerably. Thus, it is predicted that this system can be designed to obtain varying relative heating rates for the ice cream and sauce layer by varying the sauce layer thickness. It is also predicted that the ratio of relative heating of'the brownie layer to the relative - heating rate of either of the other layers can be adjusted by varying the sauce layer thickness. Therefore, it is predicted that a variety of relative heating rates and thus a variety of final preparation temperatures and/or times may be achieved by varying the chocolate sauce layer in this system. 88/01476 97 Example 9 FISH SANDWICH (POSITION OF LAYERS EXAMPLE) Relative heating rates were generated for three edible layers (two slices of bread and one slice of fish) using the computer program contained herein and the data in the table below. Two different stacking orders were evaluated. In the first stacking order the fish was placed between the two slices of bread in the conventional manner (see Figure 37). In the second stacking order the fish was placed on top of the two slices of bread (see Figure 38). Surprisingly, it was predicted that the fish would have a lower relative heating rate when it was on the top of the bread .slices than it would have between the two bread slices. This is observed in comparing the relative heating rate curve from the top to a distance 1 cm from the top in Figure 38 to the relative heating rate curve from 1 cm to 2 cm from the top in Figure 37. (cp) (P ) Heat Capacity Density Layer E' E" Thickness (cal/o deq C) ,q/ml> Bread 2.85 0.75 1.0 cm 0.5 0.15 Fish 44.5 10.5 1.0 cm 1.0 1.0 Shelf 4.0 4-Oxlθ "3 0.6 cm 0.2 2.23 Air 1.0 0.0 0.9 cm 0.24 1.3xlθ "' SHEE β υ β βT Tuτs Example 10 EFFECT OF POSITIONING THE PRODUCT IN THE OVEN ON THE SHELF OR RAISED The effect of an air gap external to the product which can have an effect on heating performance is shown in Figures 39 and 40. These figures show a theoretical comparison of the relative heating rate in a fish sandwich and a ham sandwich as they are placed on the oven's glass shelf or raised 2.0 cm above the shelf, for example, by interposing a cardboard box. The physical parameters used in the model calculations are given below: FISH SANDWICH PARAMETERS Layer * Material Thickness E' E" CP 0 4 (top) Bread 1.0 cm 2.85 0.7S 0.5 0.15 3 Fish 1.0 cm 44.5 10.S 1.0 1.0 2 Bread 1.0 cm 2.85 0.7S 0.5 0-15 1 (bottom) Air 0 - 2 cn 1.0 0.00 0.24 1.3xl0~ 3 - Glass shelf 0.6 era 4.0 4.3x10 " -3 0.2 2.23 - Air gap 0.9 cm 1.0 0.00 0.24 1.3xlθ "3 _ Metal floor 0.2 Conductivity - 3.5 x 10 b (ohm cm r 1 HAM SANDWICH PARAMETER-! &aγer f Material Thickness E" CP ø 4 (top) Bread 1.0 cm 2.85 0.75 0-5 0.15 3 Ham 0.5 cm 51.8 29.0 1.0 1.0 2 Bread 1.0 cm 2.85 0.75 0.5 0.15 1 (bottom) Air 0 - 2 cm 1.0 0.00 0.24 1.3xlθ "3 - Glass shelf 0.6 cm 4.0 4.3xl0" 3 0.2 2.23 - Air gap 0.9 cm 1.0 0.00 0.24 1.3X10 "3 - Metal floor 0.2 Conductivity - 3.5 x 10 S (ohm cm) " MODEL RESULTS % POWER ABSORBED Laver *1 fair αao> Bread <#4) Meat ι*3) Bread < *2 ) thickness FISH 0.0 cm 7.1 % 50.1 % 10.7 % 2.0 cm 6.7 % 26.3 % 8.6 % HAM 0.0 cm . 12.3 % 30.7 % 15.3 % 2.0 cm 12.4 % 23.1 % 13.3 % In the fish sandwich example, the percentage power absorbed and the relative heating rate (Figure 40) in the fish layer are quite sensitive to the air gap thickness between product and glass shelf while in the ham sandwich example, the percentage power absorbed and ' the relative heating rate (Figure 39) in each layer is relatively insensitive to the air gap thickness. SUBSTITUTE SHEET A-l APPENDIX A © COPYRIGHT THE PILLSBURY COMPANY 1987 ALL RIGHTS RESERVED INTEGER SCALAR L INTEGER SCALAR GLOBAL 2000 GLOBAL := \ ==> 2000 points, LMAX layers INTEGER SCALAR LMAX 10 LMAX := \ Max # of layers permissible INTEGER SCALAR SLICE GLOBAL LMAX / SLICE := ECHO.OFF INTEGER SCALAR LI INTEGER SCALAR l INTEGER SCALAR K2 INTEGER SCALAR 3 '" INTEGER SCALAR K4 INTEGER SCALAR II INTEGER SCALAR 12 INTEGER SCALAR 3 INTEGER SCALAR 14 INTEGER SCALAR NSLICE INTEGER DIMC 2 ] ARRAY FLAG INTEGER DIMC 25 ] ARRAY C DP.REAL DIMC 25 ] ARRAY QM REAL DIMC 50 ] ARRAY XOBS REAL DIMC 50 ] ARRAY YOBS REAL DIMC 3 ] ARRAY XC REAL DIMC 3 ] ARRAY .YC DP. EAL DIMC 2 ] ARRAY DS f_^π ηi^**<_?='«_'n n- ζ£ ■ is'_=- -_•' - - - ; A-2 DP. EAL SCALAR E DP. EAL SCALAR PB DP. EAL SCALAR PINC DP.REAL SCALAR XSHIFT DP. EAL SCALAR DMIN DP. EAL SCALAR DMAX DP. EAL SCALAR DXI DP.REAL SCALAR STEP DP.REAL SCALAR MAX DP. EAL SCALAR QM DP.REAL SCALAR RS DP. EAL SCALAR RM DP.REAL SCALAR RSI DP.REAL SCALAR SF # DP.REAL SCALAR SB DP.REAL SCALAR P DP.REAL SCALAR PP DP.REAL SCALAR F DP.REAL SCALAR NI DP.REAL SCALAR El DP.REAL SCALAR SM DP.REAL SCALAR SMI DP.REAL SCALAR Z DP.REAL SCALAR Tl DP.REAL SCALAR T2 DP.REAL SCALAR DELTA DP. EAL DIMC GLOBAL ] ARRAY QG DP.REAL DIMC GLOBAL ] ARRAY QGR DP.REAL DIMC GLOBAL ] ARRAY XG DP.REAL DIMC SLICE ] ARRAY XI SUBST-.TUTE SHEET A-3 DP.REAL DIMC LMAX 4 + ] ARRAY DX DPΛHEAL DIMC LMAX 4 + ] ARRAY CP DP.REAL DIMC LMAX 4 + ] ARRAY RHO DP.REAL DIMC LMA 4 + ] ARRAY QAVG DP. EAL DIMC LMAX 4 + ] ARRAY XO DP.REAL DIMC LMAX 4 + J ARRAY PPA DP.COMPLEX DIMC LMAX 4 + ] ARRAY N DP.COMPLEX DIMC LMAX 4 + ] ARRAY G_ DP.COMPLEX DIMC LMAX 4 + ] ARRAY GD_ DP.COMPLEX DIMC LMAX 4 + ] ARRAY GD2_ DP.COMPLEX DIMC LMAX 5 + ] ARRAY RE DP.COMPLEX DIMC LMAX 5 + ] ARRAY TE DP-COMPLEX DIMC LMAX 5 + ] ARRAY TR DE..COMPLEX DIMC LMAX 5 + ] ARRAY RI DP ' .COMPLEX SCALAR NI DIMC LMAX 4 + , 1 ] STRING.ARRAY WHAT ϊ STRING AA HAD FAST.VIDEO.PLOTS.ON : CALC.Q 0. DUP DϋP DϋP DϋP XG := XO := QAVG := QG := PPA := 0. 0. Z=X+IY DϋP DϋP G_ := GD__ := GD2_ := STACK.CLEAR 0. 0. Z=X+IY DϋP DϋP DϋP RI := RE := TE := TR := N C 1 ] 1. - N C 1 ] 1. + / DϋP RI C 1 ] := RE C 1 3 •'= 2. N 1 3 * N C 1 3 1. + / TE C 1 3 == 1. L 3 ~ 1. N C L 3 + / RI C LI 3 •= l.D Z=0+IY N * -2.D * DPI * 12.236294D / G_ := -4.0D DPI * 12.236294D / PP r= G_ DX * DϋP EXP GD_ := 2.D * EXP GD2_ := LI 1 DO I 1 + II := N [ II ] N [ I ] - N [ II ] N [ I ] + / RI [ II ] := A-4 GD2_ C I 3 RE C I 3 * RI C II 3 + GD2_ [ I ] RE [ I ] * RI [ II ] * 1. + / RE [ II ] := 2. N C II 3 * N C II 3 N C I 3 + / GD2_ C I 3 RE C I 3 * RI C II 3 * I- + / TE [ II 3 == LOOP TE LI 3 TR LI 3 := 1 L DO TE C I 3 GD_ C I 3 * TR C I 1 + 3 * TR [ I := XO [ I 1 + ] DX [ I 1 + ] + XO [ I ] := -1 +LOOP LI 4 DO GLOBAL 1 + 1 3 - SLICE * - K4 : = DX I 3 DϋP SLICE FLOAT / SWAP XI [ 3 FILL 2. DX I 3 * XI ~ G_ C I 3 * EXP RE C I 3 * XI G_ C I 3 * EXP + TR C I 1.+ 3 * E * ZMAG DϋP * 3.255364E-4 * CP [ I ] RHO [ I ] / N C I 3 DϋP * ZIMAG * NEG QG SUBC K4 , SLICE 3 := XI XO C I 3 + XG SUBC K4 , SLICE 3 == LOOP 0. 0. Z=X+IY DUP DϋP DϋP RE := TE := TR := RI := \ BELOW N C L 3 1. " N C L 3 1. + / DϋP RI C LI ] : = RE [ LI 3 == 2. N [ L ] * N [ ] 1. + / TE [ LI ] :s 3 L DO \ BELOW beam incident on *3, the glass sh I 1 - II := N C II 3 N C I 3 - N C II 3 N C I 3 + / RI C I 3 — GD2_ C I 3 RE C I 1 + 3 * RI C I 3 + GD2_ [ I ] HE [ H + ] * HI [ I ] * 1. + / HE [ I ] := 2. N C II 3 * N C II 3 N C I 3 + / GD2_ [ I ] RE [ I 1 + ] * RI [ 1 3 * 1. + / TE [ I ] ' : = -1 +LOOP TE C 3 3 TR [ 3 3 := A-5 LI 3 DO TE C I 1 + 3 GD_ [ I 3 * TR [ I 3 * TR C I l + 3 == LOOP 0. XO C 4 3 := \ re-define x-axis zero from BELOW to 4*4, first product LI 4 DO I 1 + II := XO C I 3 DX C I 3 + XO C II 3 •= GLOBAL 1 + 1 3 - SLICE * - K4 := DX C I 3 DϋP SLICE FLOAT / SWAP XI 3FILL 2. DX C I 3 * XI - G_ [ I 3 * EXP RE C II 3 * XI G_ [ I 3 * EXP + TR [ I 3 * E * ZMAG DϋP * PB * 3.255364E-4 * CP [ I ] / RHO [ I 3 / N C I 3 DϋP * ZIMAG * NEG REV[ 1 3 QG SUBC K4 , SLICE 3 + DϋP QG SUBC K4 , SLICE 3 — MEAN QAVG C I 3 == LOOP QAVG PP * 4.1868 * DX * CP * QG 'SUB K2 , 12 3 C3MAX QMAX := RHO * PINC- / PP / PPA := ; R.SDB XG SϋBC K2 , 12 3 QGR SUBC K2 , 12 3 ; Q.SϋB XG SUBC K2 , 2 3 QG SUBC K2 , 12 ] ; SCREEN.SET.UP 16 GRAPHICS.DISPLAY.MODE GRAPHICS.DISPLAY AXIS.DEFAULTS 3 VϋPORT.COLOR 3 CURSOR.COLOR 0 AXIS.COLOR 0 LABEL.COLOR 0 COLOR " ' * SYMBOL XC YC XY.AUTO.PLOT SOLID ; : HP.SET.UP HP7440 PLOTTER.DEFAULTS AXIS. EFAULTS 1 AXIS.COLOR 1 LABEL.COLOR \ " VS 10" GRAPH.COMMAND VERTICAL GRID.OFF HORIZONTAL GRID.OFF 1 COLOR " " SYMBOL XC YC XY.AUTO.PLOT SOLID ; : R.LABEL.SCREEN 0 COLOR NORMAL.COORDS .3 .98 POSITION " Relative Heating Profile" LABEL .35 .05 POSITION " Distance from Top, cm" LABEL EET A-6 270 LABEL.DIR .025 .8 POSITION " Relative Heating Rate" LABEL .975 .3 POSITION " shelf" LABEL .05 .05 POSITION WORLD.COORDS ; : R.LABEL.HP 1 COLOR NORMAL.COORDS .4 .98 POSITION " Relative Heating Profile" LABEL .4 .05 POSITION " Distance from Top, cm" LABEL 90 LABEL.DIR .05 .4 POSITION " Relative Heating Rate" LABEL .97 .15 POSITION " shelf" LABEL WORLD.COORDS ; : Q.LABEL.SCREEN 0 COLOR NORMAL. COORDS .4 .975 POSITION " Heating Profile" LABEL .35 .05 POSITION " Distance from Top, cm" LABEL 270 LABEL.DIR .025 .75 POSITION " Degrees C / Sec" LABEL .975 .3 POSITION " shelf" LABEL .05 .05 POSITION -1 0 SCI.FORMAT CR LABEL.SCALE. . ." * Y-Axis" -1 3 FIX.FORMAT WORLD.COORDS ; : Q.LABEL.HP 1 COLOR NORMAL.COORDS .5 .975 POSITION " Heating Profile" LABEL .4 .05 POSITION " Distance from Top, cm" LABEL 90 LABEL.DIR .05 .45 POSITION " Degrees C / Sec" LABEL .97 .15 POSITION " shelf" LABEL -1 0 SCI.FORMAT CR LABEL.SCALE.Y . ." * *Yγ- -AAxxiiss"' -1 3 FIX.FORMAT WORLD.COORDS ; : MENU.PLOT CR . " Report: " CR .' REPORT.SCREEN" CR . " REPORT.PRN" CR . " New Case: GO" CR .' Change a Layer: " CR . CHANGE" CR . " Plot:" CR .' PLOT.SCREEN" CR ." Q.PLOT.SCREEN' CR ." PLOT.HP" CR ." Q.PLOT.HP" CR . " Scan a Layer: ' CR ." SCAN" CR ." Q.SCAN" ; : PLOT.SCREEN SCREEN.SET.UP 0 COLOR R.SUB XY.DATA.PLOT R.LABEL.SCREEN MENU.PLOT ; : PLOT.HP HP.SET.UP 1 COLOR R.SUB XY.DATA.PLOT R.LABEL.HP 0 COLOR MENU.PLOT ; A-7 : RESTORE CR . " Calculating . . E DϋP * DϋP PB * + 376.73 / PINC := CALC.Q QG QMAX / QGR := XG SUBC K2 , 12 3 CJMAX DϋP DUP XC [ 2 ] := XC [ 3 ] := 300. / DϋP XSHIFT := XG + XG := PLOT. SCREEN ; : METAL .5 DELTA := 1 FLAG := RS DUP RM : = SB .1 * * INV Tl : = BEGIN RS RM - 0. <= IF DELTA RM RS - RS / * Tl * Tl + Tl := FLAG [ 1 3 FLAG [ 2 := 1 FLAG [ 1 3 == FLAG C 1 3 FLAG [ 2 3 = NOT IF DELTA .5 * DELTA := THEN . . ELSE . DELTA RM RS - RS / * Tl *'Tl + Tl := FLAG C 1 3 FLAG C 2 3 := -1 FLAG [ 1 ] :: FLAG C 1 3 FLAG C 2 3 = NOT IF DELTA .5 * DELTA := THEN THEM Tl P / Z := Z 10. < IF 1. F := 0. DϋP NI := SM := BEGIN 1. NI + NI := NI F * F := -1. NI ** Z NI ** * F / NI / SM + SMI := SMI SM - SMI / SMI SM := ABS 1E-5 < A-8 UNTIL -.57721 Z LN - SM - El ELSE 0. El := THEN 1. 3. 8. / Z / - 6. 10. Z * - Z 2. ** - Z 3. ** + Z NEG EXP * Z / 16. / + 12. Z 2. ** - Z * 16. / El * + SB * SF := SF Tl * INV RM := RS RM - RS / ABS IE ' - 4 < UNTIL l.OD SF 733.69362D * Z=X+IY CONJ SORT ; : INPUT. DATA CR ." Layer " Kl . CR . " e' = " #INPUT IF ' CR . " e" = " #INPUT Z=X+IY CONJ SORT N [ Kl 3 + ] := CR ." Layer thickness, cm = " #INFϋT DX [ Kl 3 + ] := CR ." Heat capacity, cal/g = " #INPUT CP [ Kl 3 + ] := CR ." Density, g/ml = " *INPUT RHO C Kl 3 + 3 := CR " F" WHAT "C Kl 3 + 3 ":= CR ELSE INTEN.ON CR ." Layer type: A, M, or S ? " "INPUT AA ":= CR INTEN AA " A" "= IF CR . Layer" Kl . . " = Air" CR ." Thickness, cm = " #INFUT DX [ Kl 3 + ] := 1.293E-3 RHO C Kl 3 + 3 = .24 CP C Kl 3 + 3 := 1. 1E-9 Z=X+IY CONJ N C Kl 3 + 3 •'= CR " A" WHAT "[ Kl 3 + 3 ":= CR THEN AA " M" "= A-9 IF CR . " Layer" Kl . . " = " Metal " CR . " Thickness , cm = " #INPDT DX [ Kl 3 + ] : = 2.71 RHO C Kl 3 + 3 • = 1 - 208 CP [ Kl 3 + 3 : = l.OD 3.65E5 733.69362D * Z=X+IY CONJ SORT N C Kl 3 + 3 " M" WHAT "C Kl 3 + 3 ":= CR THEN AA S" "= IF CR . " Layer" Kl . . " = Susceptor" 1. RHO C Kl 3 + 3 := 1E6 CP C Kl 3 + 3 == CR ." Bulk Conductivity, (Ohm cm)~-l = *INPUT SB := CR ." e Mean Free Path, cm = " »INPUT P := CR ." Surface Resistance, Ohm/sq (typical Rs>=500) = " ' SINPUT RS := METAL N [ Kl 3 + ] := Tl DX [ Kl 3 + ] :=. " S" WHAT "C * Kl 3 + 3 "Ϊ= CR THEN THEN STACK.CLEAR ; : OVEN.SET.DP .2 DX C 1 3 -'= l.D -3.65E5 733.69326D * Z=X+IY SORT N [ 1 3 == 1. 1E-6 Z=X+IY CONJ N C 2 3 — CR ." Oven Parameter Set-up:" CR CR ." Incident Electric Field (V/cm) RMS = " SINPUT E := CR . " Ratio of incident power BELOW/ABOVE = " SINFUT PB := CR ." Distance from metal floor to glass shelf, cm = " 8INFUT DX [ 2 3 CR ." Enter properties of glass shelfr" CR ." e' = " #INPϋT CR ." ' e" = " #INPUT Z=X+IY CONJ SORT N [ 3 ] := CR ." Shelf thickness, cm = " i*INPUT DX [ 3 3 := ; : GO STACK.CLEAR NORMAL.DISPLAY SUBSTITUTE SHEET A-10 " F" WHAT ":= 0. DϋP DUP DUP XI : = XC : = YC : = DX : = 1. DUP DϋP YC C 3 3 == RHO := CP := 1. Z=X+I0 N := CR . " MODEL GEOMETRY : " CR CR ." Top ! Layer ! Layer !....' Layer ! Layer ! ! ! Glass j Air ! Meta - 1 CR ." Surface ! #n ! *(n-l) !... ! #2 ! #1 ! ! ! Shelf ! Air ! Floo ^ CR . " COPYRIGHT" CR ." THE PILLSBURY COMPANY" CR ." 1987" CR CR ." Enter the number of layers in your model, NOT including the oven flo CR . " the glass shelf or the air layer between them. Use GO to change ove CR ." parameters. This version of OVEN accomodates up to 10 product/packa CR ." layers, and more can be added if necessary." CR INTEN.ON CR . " Note that the BOTTOM LAYER is Layer *1." CR ." Be sure CAPS LOCK is ON." CR . " For layers of Air, Metal, or Susceptors, answer the request for e'" CR ." with a <CR> and follow instructions." CR INTEN.OFF OVEN.SET.UP CR ." # of PRODUCT/PACKAGE Layers = " SINPUT 3 + L := 1 L + LI := LI 4 DO I 3 - Kl := INPUT.DATA LOOP SLICE L 3 - * 12 := GLOBAL 1 + L 3 - SLICE * - K2 := RESTORE ; : REPORT.BODY -1 3 FIX.FORMAT CR ." Top ! Layer j Layer J... I Layer ! Layer ! ! ! Glass j Air ! Metal" * CR ." Surface ! #n ! *(n-l) !... ! #2 ! *l i l l Shelf ! Air ! Floor" CR ." INPUT DATA: Incident E-field =" E . ." volts/cm RMS CR ." Incident power ratio: BELOW/ABOVE =" PB . =>" PINC . ." watts/cπT2" CR ." Layer e* Thickness Cp Rho" SUBSTITUTE SHEET A-ll CR ." cm cal/g deg C g/ml" 4 L DO -1 0 FIX. FORMAT I 3 - . 8 4 F ^IIX..FFOORRMMAATT ." " N C I 3 DϋP * . DX C I 3 • •" " C. : i 3 • - ,r " RHO C I 3 • CR -1 +LOOP ." Shelf " N C 3 3 DϋP * " DX [ 3 3 CP C 3 3 • •" RHO C 3 3 • CR ." Air " N C 2 3 DUP * " DX C 2 3 CR . " Metal Floor " CR 4 L DO WHAT "C I 3 * ' S" "= IF CR ." SUSCEPTOR LAYER #" -1 2 FIX.FORMAT I 3 - . Rs, Ohm/sq = " RS . -1 2 SCI.FORMAT CR ." e* (equivalent) =" N C I 3 DUP * Thickness, cm =" Tl . CR ." Conductivity/(ohm cm) =" SB . ." Mean free path, cm =" P -. C THEN -1 +LOOP CR ." RESULTS:" CR ." Layer Heating Rate, deg C/s %Power" CR ." AVG MAX MIN ABSORBED" CR 4 L DO -1 0 FIX.FORMAT 1 3 - . ." " 6 FIX.FORMAT QAVG [ 1 . ." GLOBAL 1 + 1 3 - SLICE * - Kl := QG SUBC Kl , SLICE 3 C3MIN/MAX . ." " -1 2 FIX.FORMAT PPA C I 3 100. * . ." " CR -1 +LOOP ; : MEND.REPORT cu ■■ CR ." Report->Printer: REPORT.PRN New Case: GO. Change a Layer: CHANGE * CR ." Plot: PLOT.SCREEN, Q.PLOT.SCREEN, PLOT.HP, Q.PLOT.HP" SUBSTITUTE SHEET . . . A-12 CR ." Scan a Layer: SCAN, Q.SCAN" ; : REPORT.SCREEN NORMAL. ISPLAY REPORT.BODY MENU.REPORT ; : REPORT.PRN - ODT>PRINTER CONSOLE.OFF * CR ." ~ - REPORT.BODY CR "DATE "TYPE TIME "TYPE CR CR . CR CONSOLE ; : Q.MENU CR ." Expt'l Data:" CR . " DATA.LOAD" CR . DATA.PLOT" ; : Q.PLOT.SCREEN QG SUB[ K2 , 12 3 [3MAX YC [ 3 ] := SCREEN.SET.UP 0 COLOR Q.SUB XY.DATA.PLOT Q. ABEL.SCREEN MENU.PLOT Q.MENU 1. YC [ 3 3 • = ; : Q.PLOT.HP QG SUBC K2 , 12 3 C3MAX YC [ 3 3 == HP.SET.UP 1 COLOR Q.SUB XY.DATA.PLOT Q. ABEL.HP-0 COLOR MENU.PLOT Q.MENU 1. YC [ 3 ] := ; : LBL • -1 2 FIX.FORMAT CR WHAT "[ 13 3 " S" "= IF . " Rs = " RS . ELSE ." D = " DX C 13 3 • THEN ; : PLOT.SCAN LBL R.SDB XY.DATA.PLOT NORMA .COORDS .05 .05 POSITION WORLD.COORDS ; : JUMP WHAT "[ 13 3 " S" "= IF DMIN STEP K3 * + RS := METAL N [ 13 3 == Tl DX [ 13 ] := ELSE DMAX STEP K3 * - DX C 13 3 '= TE 3HEET A-13 THEN ; :. MEND.. SCAN CR; .." • SCAN Layer" 13 3 - . CR . " Max =" DMAX . CR" . " Min =" DMIN . CR . " Step =" STEP . CR CR ." New Scan:" CR ." SCAN" CR ." Q.SCAN" CR- .." Scan->Plotter:" CR ." SCAN.HP" CR ." Q.SCAN.HP" CR; . •• Restore Initial" CR ." Conditions:" CR ." RESTORE" CR..." New Case: GO" XG XSHIFT NSLICE * - XG := ; : SCAN.SET.DP 0. DϋP QM := DS := 0 C := RS RSI := 1. DUP DDP DDP DϋP C C 2 3 := C C 5 3 := C C 8 3 := C [ 11 3 : = C [ 14 3 : 2 DDP DϋP DDP DϋP C [ 3 ] := C C 6 3 =.= C C 9 3 := C [ 12 3 := C C 15 3 ■ CR ." Layer S" SINFϋT 3 + 13 := WHAT "C 13 " S" "= IF DX: C: 13 3 DXI := N C 13 J- NI := GR ." Max Rs, Ohm/sq = ' " #INPUT DS [ 1 ] :- CR, ." Min Rs, Ohm/sq = " #INPUT DS [ 2 3 '= D5! C3MIN/MAX DMAX := DMIN := CR ." Rs Step Size," CR ." Ohm/sq = " SINFDT STEP := DMAX DMIN - STEP / NSLICE := DMIN RS := METAL N [ 13 ] := Tl DX [ 13 ] := ELSE DX C 13 3 DXI := N C 13 3 NI := CR ." Max D, cm = " #INPϋT DS C 1 3 := CR..." Min D, cm = " 4*INPϋT DS [ 2 ] := DS " C3MIN/MAX DMAX := DMIN := DMAX DX [ 13 3 == CR ." Step Si2e, cm = " »INPUT STEP := DMAX DMIN - STEP / NSLICE := THEN CR ." Calculating . ." 0. DDP XC [ 2 3 = XC [ 3 3 • • = LI 4 DO SUBSTITUTE SHEET A-14 XC [ 3 3 DX [ I 3 + XC [ 3 ] : = LOOP XC C 3 3 DDP C [ 2 3 '= 300. / XSHIFT := 1 NSLICE + 0 DO I K3 := JUMP CALC.Q QMAX QM C I 1 + ] == LOOP ; : SCAN SCAN.SET.DP QM C3MAX QMW := 1. YC [ 3 ] := SCREEN.SET.DP R.LABEL.SCREEN 1 NSLICE + 0 DO I K3 := JUMP CALC.Q QG QMW / QGR := 1 1 + XSHIFT * XG + XG := C [ I 1 + 3 COLOR SOLID PLOT.SCAN LOOP DXI DX C 13 3 == RSI RS := NI N C 13 ' 3.:= MEND.SCAN ; SCAN.HP HP.SET.UP R.LABEL.HP 1 NSLICE + 0 DO I K3 := JDMP CALC.Q QG QMW / QGR := 1 1 + XSHIFT * 2. / XG + XG := 1 1 + COLOR SOLID PLOT.SCAN REPORT.PRN LOOP DXI DX [ 13 3 — RSI RS := NI N [ 13 3 := 0 COLOR MEND.SCAN ; Q.PLOT.SCAN LBL Q.SDB XY.DATA.PLOT NORMAL.COORDS .05 .05 POSITION WORLD.COORDS ; Q.SCAN SCAN.SET.DP QM C3MAX QMW := QMW YC [ 3 3 ■ = SCREEN.SET.DP Q.LABEL.SCREEN 1 NSLICE + 0 DO I K3 := JUMP CALC.Q 1 1 + XSHIFT * XG + ' XG := C [ I 1 + 3 COLOR SOLID Q.PLOT.SCAN LOOP DXI DX C 13 3 == 1. YC C 3 3 — MEND.SCAN Q.MEND ; A-15 : Q.SCAN.HP QMW YC [ 3 3 := HP.SET.DP Q .LABEL.HP 1 NSLICE + 0 DO I K3 := JUMP CALC.Q 1 1 + xsHirr * 2. / G + XG := 1 1 + COLOR SOLID Q.PLOT.SCAN REPORT.PRN LOOP DXI DX C 13 3 := RSI RS := NI N [ 13 3 ■ - 1. YC C 3 3 == 0 COLOR CR MENU.SCAN Q.MENU ; : DATA.PLOT WORLD.COORDS 2 COLOR " +" SYMBOL XOBS SUBC 1 , 14 3 YOBS SUBC 1 . 14 3 XY.DATA.PLOT 0 COLOR NORMAL.COORDS .05 .05 POSITION WORLD.COORDS ; : DATA.LOAD 0. DDP YOBS := XOBS := CR ." * X-Y Pairs," CR ." 50 max = " SINPDT 14 := CR 114 + 1 DO CR I . CR .V Q Deg C/Sec =" CR #INFDT YOBS C I 3 := CR ." Cm from TOP =" CR SINFDT XOBS C I 3 - CR LOOP DATA.PLOT MEND.PLOT : CHANGE NORMAL.DISPLAY CR . " Which layer do you want to change? " #INFDT Kl = INPDT.DATA RESTORE ; : GRO GRAPHICS.READOUT NORMAL.COORDS 0.65 0.93 READODT>POSITION .5 .5 POSITION 0 CDRSOR.COLOR WORLD.COORDS ; ECHO.ON SUBSTITUTE SHEET

Claims: What is claimed and desired to be secured by letters patent is: 1. A food system including a food product and a microwave oven for controlled heating of said food product in said microwave oven, said food system comprising: a) at least one layer of edible component having properties including thickness, dielectric properties and position; b) at least one layer of material proximate said at least one edible component said at least one layer of material having properties including thickness, dielectric properties and position; and c) at least one of the following three selections being made; i) at least one of said thickness, dielectric properties, number of said layers and position of the edible component being selected relative to at least one of said thickness, dielectric properties, number of said layers and position of said material, ii) the position of said at least one edible component relative to said at least one layer of material, and iii) the number of at least one of said edible component and said material for the purpose that at least one of said at least one edible component will have at least one of the following performance characteristics; i) heat to within a preselected temperature range, ii) heat to within a preselected time range, iii) heat to within a preselected temperature range within a preselected time range, iiii) will have a thickness tolerance of 7.5% of the wavelength of the microwave in said at least one layer of edible component at a time just prior to exposure to microwave radiation and iiiii) will have a preselected deposition of power within said at least one layer of edible component at a time just prior to microwave radiation during exposure to microwave radiation. 2. A food system as set forth in Claim 1 including: a) said at least one edible component having had at least one of said properties adjusted in accordance with results of analyzing at least one of said performance characteristics of said at least one edible component using interference analysis techniques. 3. A food system as set forth in Claim 1 wherein. a) there are a plurality of similar said food products for heating in a microwave oven with each said food product having at least one edible component and wherein the thickness of said at least one edible component at a temperature just prior to exposure to microwave radiation will have a variation in said thickness from at least one of a selected and an average value of the thickness for a substantial number of each of said at least one edible component of each said food products maintained within a tolerance range of within about .+7.5% of the wavelength of the microwave in said edible component. 4. A food system as set forth in Claim 1 wherein: a) there are a plurality of similar said food products for heating in a microwave oven with each said food product having at least one edible component having thickness and dielectric properties at a temperature just prior to exposure to microwave radiation and wherein variations in said thickness and dielectric properties from at least one of a selected and an average value of the thickness and dielectric properties for a substantial number of each of said at least one edible component of each of said food products are maintained within a tolerance range to approximately obey the inequality: nΔt +■ tΔn < (0.075)(12.24) cm. 5. A food product in a microwave oven for controlled heating therein, comprising: « a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 6. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat to within a ιιq preselected temperature range during exposure to microwave radiation. 7. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 8. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 9. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being; selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 10. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at ' least one edible component, said at least one layer of material having dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 11. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness and dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material for the purpose that' said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 12. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 13. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; ' b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. * 14. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave ' radiation. 15. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 16. A food product in a microwave oven for controlled heating therein, comprising: > a) at least one layer of edible component having thickness and dielectric properties; b) t * least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 17. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness and dielectric properties of said at least one edible component ' , at a time just prior to exposure to microwave radiation being selected, relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 18. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at .least one edible component, said at least one layer of material having thickness and dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 19. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 20. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 21. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 22. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of materxal proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 23. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 24. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 25. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b ) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness and dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 26. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 27. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) a't least one layer of material proximate said at least one edible component, -said at least one layer of material having dielectric properties; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 28. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said - at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 29. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 30. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure. to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 31. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 32. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness and dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 33. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 34. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness of said at least one edible component, at a time jnst prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 35. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 36. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having dielectric properties; b) at least one layer of material proxxmate said at least one edible component, said at least one layer of material having dielectric properties; and c) the dielectric properties of said at least one edible component, at a time just prior to exposure. to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 37. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 38. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 39. A food product in a microwave oven for controlled heating therein, comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component, said at least one layer of material having thickness and dielectric properties; and c) the thickness and dielectric properties of said at least one edible component, at a time jus. prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at . least one layer of material for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. ■ H3 40. A food product in a microwave oven for controlled heating therein comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component having thickness and dielectric properties; and c) he position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 41. A food product as set forth in Claim 40 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 42. A food product as set forth in Claim 40 including: a) the dielectric properties of said at least one edible component, at a time ' just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 43. A food product as set forth in Claim 40 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 44. A food product as set forth in Claim 40 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 45. A food product as set forth in Claim 40 including: a) the dielectric properties of said at least one edible .component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 46. A food product as set forth in Claim 40 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one lavβr of material being selected for the purpose that said ac least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 47. A food product as set forth in Claim 40 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 48. A food product as set forth in Claim 40 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of U7 material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one' edible component will heat to within a preselected temperature range during exposure to microwave radiation. 49. A food product as set forth in Claim 40 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material and the position * of said at least one edible component relative to said at' least one layer of material being selected for the purpose that said at least one edible component will heat to within a preselected temperature range during exposure to microwave radiation. 50. A food product in a microwave oven for controlled heating therein comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component having thickness and dielectric properties; and c) the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 51. A food product as set forth in Claim 50 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 5-2. A food product as set forth in Claim 50 including: a) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 53. A food product as set forth in Claim 50 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 54. A food product as set forth in Claim 50 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 55. A food product as set forth in Claim 50 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 56. A food product as set forth in Claim 50 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 57. A food product as set forth in Claim 50 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 58. A food product as set forth in Claim 50 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. _ 59. A food product as set forth in Claim 50 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected time range during exposure to microwave radiation. 60. A food product in a microwave oven for controlled heating therein comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component having thickness and dielectric properties; and c) the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 61. A food product as set forth in Claim 60 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected .temperature range within a preselected time' range during exposure to microwave radiation. 62. A food product as set forth in Claim 60 including: a) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 63. A food product as set forth in Claim 60 including: a) the thickness- of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 64.- A food product as set forth in Claim 60 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 65. A food product as set forth in Claim 60 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 66. A food product as set forth in Claim 60 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 67. A food product as set forth in Claim 60 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 68. A food product as set forth in Claim 60 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 69. A food product as set forth in Claim 60 including: a) the thickness and dielectric properties of said at least one edible, component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 70. A food product in a microwave oven for controlled heating therein comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component having thickness and dielectric properties; and c) the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 71. A food product as set forth in Claim 70 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 72. A food product as set forth in Claim 70 including: a) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 73. A food product as set forth in Claim 70 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 74. A food product as set forth in Claim 70 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to mxcrowave radiation. 75. A food product as set forth in Claim 70 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said _ at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in ' said at least one- layer of edible component at a time just prior to exposure to microwave radiation. 76. A food product as set forth in Claim 70 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a -thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 77. A food product as set forth in Claim 70 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have, a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just" prior to exposure to microwave radiation. 78. A food product as set forth in Claim 70 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 79. A food product as set forth in Claim 70 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 80. A food product in a microwave oven for controlled heating therein comprising: a) at least one layer of edible component having thickness and dielectric properties; b) at least one layer of material proximate said at least one edible component having thickness and dielectric properties; and c) the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. A food product as set forth in Claim 80 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 82. A food product as set forth in Claim 80 including: a) the dielectric properties of said at least one edible component, at a time just prior to exposure to microwave radiation and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 83. A food product, as set forth in Claim 80 including: a) the thickness of said at least one edible component at a ~ time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 84. A food product as set forth in Claim 80 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 85. A food product as set forth in Claim 80 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 86. A food product as set forth in Claim 80 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 87. A food product as set forth in Claim 80 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 88. A food product as set forth in Claim 80 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 89. A food product as set forth in Claim 80 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of said at least one layer of material and the position of said at least one edible component relative to said at least one layer of material being selected for the purpose that said at least one edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 90. A food product in a microwave oven for controlled heating therein comprising: a) a plurality of layers proximate one another with at least one of said layers being an edible component each said layer having thickness and dielectric properties; and b) the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 91. A food product as set forth in Claim 90 including: a) the number of said layers and the position of at least one of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 92. A food product as set forth in Claim 90 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for -the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 93. A food product as set forth in Claim 90 including: a) the dielectric properties of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 94. A food product as set forth in Claim 90 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 95. A food product as set forth in Claim 90 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 96. A food product as set forth in Claim 90 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 97. A food product as set forth in Claim 90 including: a) the thickness and dielectric properties of said at least .one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 98. A food product as set forth in Claim 90 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 99. A food product as set forth in Claim 90 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat to within a preselected temperature range during exposure to microwave radiation. 100. A food product in a microwave oven for controlled heating therein comprising: a) a plurality of layers proximate one another with at least one of said layers being an edible component each said layer having thickness and dielectric properties; and b) the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 101. A food product as set forth in Claim 100 including: a) the number of said layers and the position of at least one of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 102. A food product as set forth in Claim 100 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 103. A food product as set forth in Claim 100 including: a) the dielectric properties of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 104. A food product as set forth in Claim 100 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 105. A food product as set forth in Claim 100 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 106. A food product as set forth in Claim 100 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. ■ * 107. A food product as set forth in Claim 100 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to mxcrowave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edxble component will heat within a preselected time range during exposure to microwave radiation. 108. A food product as set forth in Claim 100 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 109. A food product as set forth in Claim 100 including: > a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected time range during exposure to microwave radiation. 110. A food product in a microwave oven for controlled heating therein comprising: a) a plurality of layers proximate one another with at least one of said layers being an edible component each said layer having thickness and dielectric properties; and b) the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 111. A food product as set forth in Claim 110 including: a) the number of said layers and the position of at least one of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 112. A food product as set forth in Claim 110 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 113. A food product as set forth in Claim 110 including: a) the dielectric properties of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 114. A food product as set forth in Claim 110 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 115. A food product as set forth in Claim 110 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 116. A food product as set forth in Claim 110 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 117. A food product as set forth in Claim 110 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 118. A food product as set forth in Claim 110 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radiation. 119. A food product as set forth in Claim 110 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will heat within a preselected temperature range within a preselected time range during exposure to microwave radxation. 120. A food product in a microwave oven for controlled heating therein comprising: a) a plurality of layers proximate one another with at least one of said layers being an edible component each said layer having thickness and dielectric properties; and b) the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 121. A food product as set forth in Claim 120 including: a) the number of said layers and the 'position of at least one of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 122. A food product as set forth in Claim 120 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will have -a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 123. A food product as set forth in Claim 120 including: a) the dielectric properties of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 124. A food product as set forth in Claim 120 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 125. A food product as set forth in Claim 120 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 126. A food product as set forth in Claim 120.including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 127. A food product as set forth in Claim 120 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 128. A food product as set forth in Claim 120 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time just prior to exposure to microwave radiation. 129. A fcod product as set forth in Claim 120 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will have a thickness tolerance of ±7.5% of the wavelength in said at least one layer of edible component at a time- ust prior to exposure to microwave radiation. 130. A food product in a microwave oven for controlled heating therein comprising: a) a plurality of layers proximate one another with at least one of said layers being an edible component each said . layer having thickness and dielectric properties; and b) the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 131. A food product as set forth in Claim 130 including: a ) the number of said layers and the position of at least one of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 132. A food product as set forth in Claim 130 including: a) the thickness of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 133. A food product as set forth in Claim 130 including: a) the dielectric properties of at least one of said layers at a time just prior to exposure to microwave radiation and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 134. A food product as set forth in Claim 130 including: a) the thickness of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 135. A food product as set forth in Claim 130 including: a) the thickness of said at least one edible component at a ' time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 136. A food product as set forth in Claim 130 including: a) the dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 137. A food product as set forth in Claim 130 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness of another of said layers and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 138. A food product as set forth in Claim 130 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one layer of edible component at a time just prior to exposure to microwave radiation. 139. A food product as set forth in Claim 130 including: a) the thickness and dielectric properties of said at least one edible component at a time just prior to exposure to microwave radiation being selected relative to the thickness and dielectric properties of another of said layers and the number of said layers being selected for the purpose that said edible component will have a preselected deposition of power within said at least one- layer of edible component at a time just prior to exposure to microwave radiation. 140. A method of making a food product for heating in a microwave oven, said method including: a) selecting at least one food product; b) determining a time/temperature relationship range for said food product to follow during heating in a microwave oven; c) determining a temperature range for said at least one food product to be heated to within during exposure to microwave radiation; and d) analyzing the performance characteristics of said at least one food product using interference analysis techniques and use results of said analysis to make an adjustment in said at least one food product whereby said at least one food product will generally heat within said time/temperature range and reach a temperature generally within said temperature range. 141. A method as set forth in Claim 140 wherein: a) said at least one food product is a plurality of food products. 142. A method as set forth in Claim 141 wherein: a) said plurality of food products are positioned in layers in a container, at least some of said plurality of food products being in superposed layers. 143. A product produced by a method of Claim 140, 141 or 142. 144. A method of making a food product for heating in a microwave oven, said food product including at least, one edible component, said method including: a) selecting at least one edible component having thickness, dielectric properties and position within a microwave oven; and b) adjusting at least one of the group of properties including thickness, at least one dielectric property and position of the at least one edible component for the purpose that said at least one edible component will heat within a preselected time/temperature relationship range to a temperature within a preselected temperature range - when exposed to microwave radiation. 145. A method as set forth in Claim 144 including: a) using interference analysis techniques to analyze at least one of said at least one edible component thickness, at least one dielectric property or position and doing said adjusting by applying results of said analysis. 146. A method as set forth in Claim 145 wherein: a) said at least one food product is a plurality of food products and each said product has position relative to one another and wherein said group of properties includes said relative position. 147. A method as set forth in Claim 146 wherein: a) said group of properties includes the number of food products. 148. A method as set forth in Claim 144, 145, 146 or 147 wherein: a) said at least one food product is in the form of a layer. 149. A method as set forth in Claim 148 wherein: a) at least two of said food products are each in the form of a layer and said layers are in superposed relation. 150. A method as set forth in Claim 145, 146 or 147 wherein: a) said microwave oven includes a metal bottom cavity wall, a support shelf and an air gap therebetween each having dielectric properties, thickness and position relative to said at least one food product; and b) including at least one of said dielectric properties, thickness and position of at least one of said metal bottom cavity wall, support shelf and said air gap in said interference analysis. 151. A method as set forth in Claim 145, 146 or 147 wherein: a) applying results of said analysis and doing said adjusting for the purpose of estimating at least one of power and energy distribution within said food product; and b) making a food product incorporating said balanced properties. 152. A method as set forth in Claim 145, 146 or 147 including: a) making a food product in accordance with the results of said analysis. 153. A method as set forth in Claim 151 including: a) testing said food product for performance and thereafter further balancing at least one edible component properties such that said at least one edible component will heat within a preselected time/temperature relationship range to a temperature within a preselected temperature range when exposed to microwave radiation. 154. A plurality of similar microwave food products each said food product comprising: a) each said food product having at least one edible component having thickness at a temperature just prior to exposure to microwave radiation and wherein variation in said thickness from at least one of a selected and an average value of the thickness for a substantial number of each of said at least one edible component of each of said food products is maintained within a tolerance range of within about ±7.5% of the wavelength of the microwave in said edible component. 155. A plurality of similar microwave food products as set forth in Claim 154 wherein: a) said thickness is maintained within about ±5%. 156. A plurality of similar microwave food products as set forth in Claim 154 wherein: a) said thickness is maintained within about ±2.5%. 157. A plurality of similar food products as set forth in Claim 154, 155 or 156 wherein said food product includes a plurality of edible components with each said edible component having its thickness within said tolerance range. 158. A plurality of similar microwave food products as set forth in Claim 157 wherein said edible components are in superposed relationship. 159. A plurality of similar microwave food products each said food product comprising: a) each said food product having at least one edible component having thickness and dielectric properties at a temperature just prior to exposure to microwave radiation and wherein variations in said thickness and dielectric properties from at least one of a selected and an average value of the thickness and dielectric properties for a substantial number of each of said at least one edible component of each of said food products are maintained within a tolerance range to approximately obey the inequality: nΔt ■*■ tΔn < (0.075) (12.24) cm. 160. A plurality of similar microwave food products as set forth in Claim 159 wherein: a) said thickness and dielectric properties are maintained such that they approximately obey the inequality: nΔt + tΔn < (0.05) (12.24) cm. 161. A plurality of similar microwave food products as set forth in Claim 159 wherein: a) said thickness and dielectric properties are maintained such that they approximately obey the inequality: nΔt + tΔn < (0.025)(12.24) cm. 162. A plurality of similar food products as set forth in Claim 159. 160 or 161 wherein said food product includes a plurality of edible components with each said edible component having its thickness and dielectric properties within said tolerance range. 163. A plurality of similar microwave food products as set forth in Claim 162 wherein said edible components are in superposed relationship. method of controlled microwave heating of a multi-component food product, said food product having at least two distinct components that are to be provided desired degrees of heating before consumption, said method comprising: (a) placing a food product in a microwave oven, said food product having at least two distinct components, a first edible component and a second edible component in proximity to one another, said food product having shield means associated therewith, said shield means shielding said first component during exposure of said food product to _ microwave radiation, said shield means including said second component, said second component being - partially trans issive of incident microwave radiation with its thickness and dielectric properties having been selected to control the amount of transmitted microwave power to the first component and thereby control heating thereof to a desired degree within a preselected time of exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period sufficient to heat at least said second component thereby achieving a predetermined temperature differential range between said first and second components during said exposure to microwave radiation. 165) The method as set forth in Claim 164 wherein said .second component has a shielding value just prior to exposure to microwave radiation in excess of about 70% of the first shielding inflection point value. 166) The method as set forth in Claim 164 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 80% of the first shielding inflection point value. 167) The method as set forth in Claim 164 wherein said second component has a shielding value just prior to exposure 'to microwave radiation in excess of about 90% of the first shielding inflection point value. 168) A method as set forth in Claim 165 wherein said second component has a free water content just prior to exposure to . microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 169) A method as set forth in Claim 165 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 170) A method as set forth in Claim 165 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 171) A method as set forth in Claim 168 wherein said second component is.in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 172) A method as set forth in Claim 168 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 173) A method as set forth in Claim 168 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 174) A method as set forth in Claim 171 wherein said second component has an ice content of less than about the 50% by weight'of said second component just prior to exposure to microwave radiation for consumption. 175) A method as set forth in Claim 171 wherein said second component has an ice content of less than about the 30% by ft weight of said second component just prior to exposure to microwave radiation for consumption. 176) A method as set forth in Claim 171 wherein said second component has an ice content of less than about the 10% by weight of said second component just prior to exposure to microwave radiation for consumption. 177) A method as set forth in Claim 164 wherein said second component has a free water .content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 178) A method as set forth in Claim 164 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 179) A method as set forth in Claim 164 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 180) A method as set forth in Claim 177 wherein said second component has an ice content of less than about 50% by weight of said second component just prior to exposure to microwave radiation for consumption. 181) A method as set forth in Claim 177 wherein said second component has an ice content of less than about 30% by weight of said second component just prior to exposure to microwave radiation for consumption. 182) A method as set forth in Claim 177 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 183) A method as set forth in Claim 177 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 184) A method as set forth in Claim 177 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5- cm. 185) A method as set forth in Claim 164 wherein said second component has an ice content of less than about 50% by weight of said second component just prior to exposure to microwave radiation. 186) A method as set forth in Claim 164 wherein said second component has an ice content of less than about 30% by weight of said second component just prior to exposure to microwave radiation. 187) A method as set forth in Claim 164 wherein said second component has an ice content of less than about 10% weight of said second component just prior to exposure to microwave radiation. 188) A method as set forth in Claim 164 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 189) A method as set forth in Claim 164 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 190) A method as set forth in Claim 164 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 191) A method as set forth in Claim 188 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 70% of the first shielding inflection point value. 192) A method as set forth in Claim 188 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 80% of the first shielding inflection point value. 193) A method as set forth in Claim 188 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 90% of the first shielding inflection point value. 194) A method as set forth in Claim 191 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 195) A method as set forth in Claim 191 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 196) A method as set forth in Claim 191 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 197) A method as set forth in Claim 188 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 198) A method as set forth in Claim 188 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 199) A method as set forth in Claim 188 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 200) A method as set forth in Claim 188 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 50% by weight of second component. 201) A method as set forth in Claim 188 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 30% by weight of second component. 202) A method as set forth in Claim 188 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 10% by weight of second component- 203) A method as set forth in Claim 164 wherein said shield means includes a metal shield in shielding relation to at least a portion of said food product and has an opening therein allowing said second component to be exposed to microwave radiation. 204) A method as set forth in Claim 164 wherein said second component contains multiple layers of immiscible edible components. 205) A method as set forth in Claim 164 wherein said first edible component includes ice cream and said second edible component includes a sweetened viscous sauce, said shield means includes metal shielding adjacent said ice cream, said second edible component and said metal shield cooperate to form said shield means which substantially completely surrounds said ice cream and said food product further includes a brownie positioned adjacent said sauce and having a substantial portion thereof unshielded from direct exposure to microwave radiation. A method of making a microwave heatable food product having at least two edible distinct components, a first component and a second component positioned in proximity to one another, said method including: (a) positioning said first component in proximity to said second component; (b) positioning shield means in microwave shielding relation to said first component, said shield means including said second component, said second component being partially transmissive of microwave radiation with its thickness and dielectric properties having been selected to control the amount of microwave power it will transmit to the first component to control microwave heating of the first component; (c) positioning said first and second components in package means; and (d) storing said first and second components in said package means. 207) The method as set forth in Claim 206 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 70% of the first shielding inflection point value. 208) The method as set forth in Claim 206 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 80% of the first shielding inflection point value. 209) The method as set forth in Claim 206 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 90% of the first shielding inflection point value. 210) " A method as set forth in Claim 207 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 211) A method as set forth in Claim 208 wherein said second component has a free water content just prior to exposure to microwave radiation or consumption in the range of between about 24% and about 90% by weight of said second component. 212) A method as set forth in Claim 209 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 213) A method as set forth in Claim 210 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 214) A method as set forth in Claim 211 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 215) A method as set forth in Claim 210 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 216) A method as set forth in Claim 213 wherein said second component has an ice content of less than about the 50% by weight of said second component just prior to exposure to microwave radiation for consumption. 217) A method as set forth in Claim 213 wherein said second component has an ice content of less than about the 30% by weight of said second component just prior to exposure to microwave radiation for consumption- 218) A method as set forth in Claim 213 wherein said second component has an ice content of less than about the 10% by weight of said second component just prior to exposure to microwave radiation for consumption. 219) A method as set forth in Claim 206 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 220) A method as set forth in Claim 219 wherein said second component has a free water content just prior to exposure to - microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 221) A method as set forth in Claim 219 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 222) A method as set forth in Claim 219 wherein said second component has an ice content of less than about 50% by weight of said second component just prior to exposure to microwave radiation for consumption. 223) A method as set forth in Claim 219 wherein said second component has an ice content of less than about 30% by weight of said second component just prior to exposure to microwave radiation for consumption. 224) A method as set forth in Claim 219 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 225) A method as set forth in Claim 219 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 226) A method as set forth in Claim 219 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 227) A method as set forth in Claim 206 wherein said second component has an ice content of less than about 50% by weight of said second component just prior to exposure to microwave radiation. 228) A method as set forth in Claim 206 wherein said second component has an ice content of less than about 30% by weight of said second component just prior to exposure to microwave radiation. 229) A method as set forth in Claim 206 wherein said second component has an ice content of less than about 10% weight of said second component just prior to exposure to microwave radiation. 230) A method as set forth in Claim 206 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 231) A method as set forth in Claim 206 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 232) A method as set forth in Claim 206 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 233) A method as set forth in Claim 230 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 70% of the first shielding inflection point value. 234) A method as set forth in Claim 230 wherein said ' second component has a shielding value just prior to exposure to .microwave radiation in excess of about 80% of the first shielding inflection point value. 235) A method as set forth in Claim 230 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 90% of the first shielding inflection point value. 236) A method as set forth in Claim 233 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 237) A method as set forth in Claim 233 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 238) A method as set forth in Claim 233 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 239) A method as set forth in Claim 230 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 240) A method as set forth in Claim 230 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 241) A method as set forth in Claim 230 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 242) A method as set forth in Claim 230 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 50% by weight of second component. 243) A method as set forth in Claim 230 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption pf less than about 30% by weight of second component. 244) A method as set forth in Claim 230 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 10% fay weight of second component. 245) A method as set forth in Claim 206 wherein said shield means includes a metal shield in shielding relation to at least a portion of said food product and has an opening therein allowing said second component to be exposed to microwave radiation. 246) A method as set forth in Claim 206 wherein said second component contains multiple layers of immiscible edible components. 247) A method as set forth in Claim 206 wherein said first edible component includes ice cream and said second edible component includes a sweetened viscous sauce, said shield means includes metal shielding adjacent said ice cream, said second edible component and said metal shield cooperate to form said shield, means which substantially completely surrounds said ice cream and said food product further includes a brownie positioned adjacent said sauce and having a substantial portion thereof unshielded from direct exposure to microwave radiation. 248) A microwave beatable food product comprising at least two edible and distinct components, said food product including: (a) a first edible component; (b) shield means positioned in proximity to said first edible component to control the amount of microwave power transmitted to the first component upon exposing said food product to microwave radiation, said shield means including a second edible component which is partially transroissive of microwave radiation with its thickness and dielectric properties having been selected to control the amount of microwave power it will transmit to the first component and thereby control the heating of said first component to a desired degree within a preselected time of exposure to microwave radiation; (c) package means containing said first and second components. 249) A product as set forth in Claim 248 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 70% of the first shielding inflection point value. 250) A product as set forth in Claim 248 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 80% of the first shielding inflection point value. 251) A product as set forth in Claim 248 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 90% of the first shielding inflection point value. 252) A product as set forth in Claim 249 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 253) A product as set forth in Claim 249 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 254) A product as set forth in Claim 249 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 255) A product as set forth in Claim 252 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 256) A product as set forth in Claim 252 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 257) A product as set forth in Claim 252 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 258) A product as set forth in Claim 255 wherein said second component has an ice content of less than about the 50% by weight of said second component just prior to exposure to microwave radiation for consumption. 259) A product as set forth in Claim 255 wherein said second component has an ice content of less than about the 30% by weight of said second component just prior to exposure to microwave radiation for consumption. 260) A product as set forth in Claim 255 wherein said second component has an ice content of less than about the 10% by weight of said second component just prior to exposure to microwave radiation for consumption- 261) A product as set forth in Claim 248 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 262) A product as set forth in Claim 261 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 263) A product as set forth in Claim 261 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and afaoυt 85% by weight of said second component. 264) A product as set forth in Claim 261 wherein said second component has an ice content of less than about 50% by weight of said second component just prior to exposure to microwave radiation for consumption. 265) A product as set forth in Claim 261 wherein said second component has an ice content of less than about 30% by weight of said second component just prior to exposure to microwave radiation for consumption. 266) A product as set forth in Claim 261 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.25 cm. 267) A product as set forth in Claim 261 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 268) A product as set forth in Claim 261 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 269) A product as set forth in Claim 248 wherein said second component has an ice content of less than about 50% by weight of said second component just prior to exposure to microwave radiation. 270) A product as set forth in Claim 248 wherein said second component has an ice content of less than about 30% by weight of said second component just prior to exposure to microwave radiation. 271) A product as set forth in Claim 248 wherein said second component has an ice content of less than about 10% weight of said second component just prior to exposure to microwave radiation. 272) A product as set forth in Claim 248 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0-25 cm. 273) A product as set forth in Claim 248 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.4 cm. 274) A product as set forth in Claim 248 wherein said second component is in a layer and has at least a majority of the thickness thereof in excess of about 0.5 cm. 275) A product as set forth in Claim 272 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 70% of the first shielding inflection point value. 276) A product as set forth in Claim 272 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 80% of the first shielding inflection point value. 277) A product as set forth in Claim 272 wherein said second component has a shielding value just prior to exposure to microwave radiation in excess of about 90% of the first shielding inflection point value. 278) A product as set forth in Claim 275 wherein said second component has a free water content jpst prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 279) A product as set forth in Claim 275 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 280) A product as set forth in Claim 275 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 281) A product as set forth in Claim 272 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 20% and about 95% by weight of said second component. 282) A product as set forth in Claim 272 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 24% and about 90% by weight of said second component. 283) A product as set forth in Claim 272 wherein said second component has a free water content just prior to exposure to microwave radiation for consumption in the range of between about 27% and about 85% by weight of said second component. 284) A product as set forth in Claim 272 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 50% by weight of second component. 285) A product as set forth in Claim 272 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 30% by weight of second component. 286) A product as set forth in Claim 272 wherein said second component has an ice content just prior to exposure to microwave radiation for consumption of less than about 10% by weight of second component. 287) A product as set forth in Claim 248 wherein said shield means includes a metal shield in shielding relation to at least a portion of said food product and has an opening therein allowing said second component to be exposed to microwave radiation. 288) A product as set forth in Claim 248 wherein said second component contains multiple layers of immiscible edible components. 289) A product as set forth in Claim 248 wherein said first edible component includes ice cream and said second edible component includes a sweetened viscous sauce in a layer in contact with the ice cream, said shield means includes metal shielding adjacent said ice cream, said second edible component and said metal shield cooperate to form said shield means which substantially completely surrounds said ice cream and, said food product further includes a brownie positioned adjacent said sauce and having a substantial portion thereof unshielded from direct exposure to microwave radiation. 290) A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product which is to have shielding controlled exposure to microwave radiation; (b) a package with said first food product therein; and (c) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave radiation shielding ability to reliably control heating of said first food product to within a desired temperature range within a predetermined time range of exposure to microwave radiation, said shield means including a second edible component having thickness and dielectric properties such that just prior to exposure to microwave radiation for consumption it has a power reflectance value in the range of between about 20% to about 90% and a power absorbance value in the range of between about 10% to about 65% and the sum of reflectance and absorbance is above about 60%, said shield means surrounding substantially the entire outer surface of the first food product, said second edible component containing at least about 20% by weight free water just prior to exposure to microwave radiation for consumption. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product which is to have shielding controlled exposure to microwave radiation; (b) a package with said first food product therein, and - (c) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave radiation shielding ability to reliably control heating of said first food product to within a predetermined temperature range within a predetermined time range of exposure to microwave radiation, said shield means including a second edible product in a layer positioned adjacent said first food product, said second edible product having a free water content just prior to exposure to microwave radiation for ' consumption in excess of about 20% by weight of said second edible product, at least a majority' of said layer having thickness in excess of about 0.25 cm. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product; (b) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave radiation shielding ability to reliably control heating of said first food product to within a predetermined temperature range within a predetermined time range of exposure to microwave radiation, said shield means including a second edible product in a layer positioned adjacent said first food product and having thickness and dielectric properties such that just prior to exposure to microwave radiation for consumption said second product has a microwave power reflectance value in the range of between about 20% and about 90%, a microwave power absorbance value in the range of between about 10% and about 65%, and the sum of reflectance and absorbance is above about 60%, said shield means surrounds substantially the entire outer surface of the first food product; and (c) a package with said first food product and second edible product therein. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product which is to have shielding controlled reduced exposure to microwave radiation; (b) a second food product which is to be subjected to increased exposure to microwave radiation; (c) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave radiation shielding ability to reliably control relative heating of said first and second food products to within respective predetermined temperature ranges for consumption within a predetermined time range of exposure to microwave radiation, said shield means including a third edible product in a layer positioned adjacent to and between said first and second food products and having thickness and dielectric properties such that the first food product will heat less and said second food product will heat more than if said third edible product were not present said third edible product being immiscible with said first and second food products during storage and at least initially during exposure to microwave radiation and just prior to exposure to microwave radiation for consumption having a microwave power reflectance value in the range of between about 20% and about 90%, a microwave power absorbance value in the range of between about 10% and about 65% and the sum of reflectance and absorbance being above about 60%, said shield means surrounding substantially the entire outer surface of the first food product; and (d) a package with said first and second food products and third edible product therein. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product which is to have shielding controlled reduced exposure to microwave radiation; (b) a second food product which is to have increased exposure to microwave radiation; (c) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave radiation shielding ability to reliably control relative heating of said first and second food products to within respective predetermined temperature ranges within a predetermined range of time of exposure to microwave radiation, said shield means including a third edible product in a layer positioned adjacent to and between said first and second food products and having thickness and dielectric properties such that the first food product will heat less and said second food product will heat more than if said third edible product were not present said third edible product being immiscible with said first and second food products during storage and at least initially during exposure to microwave radiation and having a free water content in excess of about 20% by weight just prior to exposure to microwave radiation for consumption, at least a majority of said layer of third edible product having thickness in excess of about 0.25 cm, said shield means surrounding substantially the entire outer surface of the first food product. (d) a package with said first and second food products and third edible product therein. A method of making a multi-component microwave heatable food product with controlled heating characteristics, said method including: (a) selecting a first edible component which is to have shielding controlled exposure to microwave radiation; (b) selecting a second edible component to be positioned proximate the first edible component to provide a microwave radiation shielding effect* for the first edible product; (c) selecting a minimum thickness for said second edible component and adjusting the dielectric properties thereof to change the power absorbance and power reflectance values and thereby adjust the time/temperature relationship for heating of said second edible component, said second edible component being immiscible with said first edible component during storage and at least initially during exposure to microwave radiation; and (d) positioning shield means in microwave shielding relationship to said first edible component said shield means having sufficient microwave radiation shielding ability to control heating of said first edible component to within a desired temperature range within a- predetermiπed time range of exposure to microwave radiation, said shield means including said second edible component. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product which is to have shielding controlled exposure to microwave radiation; (b) a package with said first food product therein; and (c) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave shielding ability to reliably control heating of said first food product to within a desired temperature range, said shield means including a second edible product having a given minimum thickness and having dielectric properties selected to achieve desired power absorbance and power reflectance values just prior to exposure to microwave radiation for consumption to achieve a desired heating differential between the first food product and the second edible product in a suitable time/temperature " relationship range for said first food product upon exposure to microwave radiation for heating said food product for consumption. A method of making a multi-component microwave food product with controlled heating characteristics when exposed to microwave radiation, said method including: (a) selecting a first edible component which is to have shielding controlled exposure to microwave radiation; (b) selecting a second edible component to be positioned proximate the first edible component in a layer of a given minimum thickness to provide a microwave shielding effect; (c) adjusting the level of free water in said second edible component to achieve desired power absorbance and reflectance values to achieve a predetermined time/temperature relationship range for said first edible component from the shielding effect of a shield means upon exposure to microwave radiation for heating the product for consumption, said second edible component being immiscible with, said first edible component during storage and at least initially during exposure to microwave radiation; and (d) positioning said shield means in microwave radiation shielding relationship to said first edible component the shield means including the second edible component formed in a layer, said second edible component having sufficient microwave shielding ability to reliably control heating of said first edible component to within a desired temperature range during exposure to microwave radiation for consumption. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first edible component which is to have shielding controlled exposure to microwave radiation; (b) shield means positioned in microwave radiation shielding relationship to said first edible component and having sufficient microwave shielding ability to reliably control heating of said first edible component to within a desired temperature range, said shield means including a second edible component having a given minimum thickness and having its free water level selected so that just prior to exposure to microwave radiation for consumption the level will be such as to achieve power absorbance and power reflectance values to provide predetermined ranges of time/temperature relationships for said first and second edible components upon exposure to microwave radiation, said second product being immiscible with said first product during storage and at least initially during exposure to microwave radiation; and (c) a package with said first and second edible components. method of making a multi-component microwave edible product or heating in a microwave oven, said method including: (a) selecting a first edible component which is to have controlled exposure to microwave radiation; (b) selecting a second edible component to be positioned proximate the first edible component to provide a microwave shielding effect for said first edible component; and (c) positioning shield means in microwave radiation shielding relationship to said first edible component and having sufficient microwave radiation shielding ability to reliably control heating of said first edible component to within a desired temperature range within a predetermined time range of exposure to microwave radiation, said shield means including said second edible component, said second edible component having a preselected level of free water just prior to exposure to microwave radiation for consumption and having thickness with at least a majority of the thickness in excess of about 0.25 cm and being adjusted to provide power absorbance and reflectance values for said second edible component to achieve predetermined time/temperature relationships for desired relative heating of said first edible component and said second edible component upon exposure to microwave radiation, said second edible component and said first edible component having a sharp change in at least one of E* and E" therebetween at least initially during exposure to microwave radiation. A multi-component microwave edible product for heating in a microwave oven, said edible product including: (a) a first edible component which is to have shielding controlled exposure to microwave radiation; (b) shield means in microwave radiation shielding relationship to said first edible component and having sufficient microwave radiation shielding ability to reliably control heating of said first edible component to within a desired temperature range within a predetermined time range of exposure to microwave radiation for consumption, said shield means including a second edible component having a given level of free water just prior to exposure to microwave radiation for consumption and a thickness selected to achieve desired power absorbance and reflectance values to achieve desired time/temperature relationships for desired relative heating of said first edible component and said second edible component upon exposure to microwave radiation for heating said product for consumption, said second edible component and said first edible component having a sharp change in at least one of E* and E" therebetween at least initially during exposure to microwave radiation; and (c) a package with said first food product therein. A method of making a multi-component microwave food product for heating in a microwave oven, said method including: (a) selecting a first edible component which is to have shielding controlled exposure to microwave radiation; (b) selecting a second edible component to be positioned proximate said first edible component; and (c) positioning shield means in microwave radiation shielding relationship to said first edible component and having sufficient microwave radiation shielding ability to reliably control heating of said first edible component to within a desired temperature range within a predetermined range of time of exposure to microwave radiation, said shield means including said second edible component, said second edible component having given dielectric properties and the thickness selected to provide power absorbance and reflectance values to achieve predetermined ranges of time/temperature relationships for relative heating of said first edible component and said second edible product upon exposure to microwave radiation, at least a majority of said thickness being in excess of about 0.25 cm, said second edible component being immiscible with said first edible component during storage thereof and at least initially during exposure to microwave radiation. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first edible component which is to have shielding controlled exposure to microwave radiation; (b) shield means 'in microwave radiation shielding relationship to said first edible component and having sufficient microwave radiation shielding ability to reliably control heating of said first edible component to within a desired temperature range within a predetermined range of time of exposure to microwave radiation for consumption, said shield means including a second edible component having given dielectric properties and thickness selected to provide desired power absorbance and reflectance values to achieve predetermined ranges of time/temperature relationships for relative heating of said first edible component and said second edible component upon exposure to microwave radiation, at least a majority of said thickness being in excess of about 0.25 cm, said second edible component being immiscible with said first edible component during storage thereof and at least initially during exposure to microwave radiation; and (c) a package with said first and second edible components therein. A method of making a multi-component microwave food product for heating in a microwave oven to achieve controlled disposition of microwave energy within said food product, said method including: (a) selecting a first food product which is to have controlled exposure to microwave radiation; (b) positioning shield means in microwave radiation shielding relationship to said first food product, said shield means having sufficient microwave shielding ability to reliably control heating of said first food product to within a desired temperature range within a predetermined range of time of exposure to microwave radiation, said shield means including a second edible component, said ' second edible component having dielectric properties within a predetermined range and thickness within a predetermined range, said second edible component being immiscible with said first food product during storage and at least initially during exposure to microwave radiation; and (c) adjusting the thickness of said second edible component within said predetermined range and adjusting the dielectric properties of said second edible component within said predetermined range to provide desired power absorbance and reflectance values for said second edible product to achieve predetermined ranges of time/temperature relationships for said first food product and said second edible component upon exposure to microwave radiation, at least a majority of said thickness being in excess of about 0.25 cm. A multi-component microwave food product for heating in a microwave oven, said food product including: (a) a first food product which is to have controlled exposure to microwave radiation; (b) shield means in microwave radiation shielding relationship to said first food product and having sufficient microwave radiation shielding ability to reliably control heating of said first food product to within a desired temperature range within a predetermined range of time of exposure to microwave radiation, said shield means including a second edible component having dielectric properties selected from within a predetermined range and thickness selected from within a predetermined range thereby providing power absorbance and reflectance values to achieve predetermined ranges of time/temperature relationships for said first food product and said second edible component upon exposure to microwave radiation, at least a majority of said thickness being in excess of about 0.25 cm, said second edible component being immiscible with said first food product during storage and at least initially during exposure to microwave radiation. method of making a multi-component microwave food product for heating in a microwave oven, said method including: (a) selecting a first food product which has thickness and dielectric properties to provide a time/temperature relationship within a predetermined range within a predetermined range of time of exposure to microwave radiation; (b) selecting a second food product with thickness and dielectric properties selected to provide a time/temperature relationship within a predetermined range within a predetermined range of time of exposure to microwave radiation said second food product being immiscible with said first food product during storage and at least initially during exposure to microwave radiation; (c) adjusting the thickness and dielectric properties of said first and second food products relative to one another such that said first food product and said second food product each reaches a temperature within its-pres.elected temperature range during exposure to microwave radiation; and (d) positioning said first and second food products adjacent to one another. A method of making a microwave beatable food product, said method including: (a) adjusting the dielectric properties of said food product to achieve a desired value for at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption at a selected thickness and forming said food product to said selected thickness whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. A method of making a microwave heatable food product, said method including: (a) selecting dielectric properties of said food product and forming said product with sufficient thickness to achieve a desired value of at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. 308) A method of making a microwave heatable food product, said method including: (a) selecting a free water level for said food product and forming said product with sufficient thickness to achieve a desired value of at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. 309) A method of making a microwave heatable food product, said method including: (a) adjusting the free water level of said food product to achieve a desired value for at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption at a selected thickness and forming said food product to said selected thickness whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. 310) A method of making a microwave heatable food product, said method including: (a) selecting an E' value for said food product and forming said food product with sufficient thickness to achieve a desired value of at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. 311) A method of making a microwave heatable food product, said method including: (a) selecting an E" value for said food product and forming said food product with sufficient thickness to achieve a desired value of at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. A method of making a microwave heatable food product, said method including: (a) adjusting the E' value of said food product to achieve a desired value for at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption at a selected thickness and forming said food product to said selected thickness whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. 313) A method of making a microwave heatable food product, said method including: (a) adjusting the E" value of said food product to achieve a desired value for at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption at a selected thickness and forming said food product to said selected thickness whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation; and (b) exposing said food product to microwave radiation for a time period to heat said food product to a temperature within a predetermined temperature range for consumption. 314) A method of making a microwave heatable food product, said method including: (a) adjusting at least one of the E' and E" values of said food product to achieve a desired value for at least one of power absorbance and reflectance just prior to exposure to microwave radiation for consumption at a selected thickness and forming said food product to said selected thickness whereby said food product will heat within a predetermined time/temperature relationship range upon exposure to microwave radiation, the value of said at least one of E* and E" being adequate to provide an acceptable tolerance range for said selected thickness.

Inventors: ANDERSON GEORGE R, ATWELL WILLIAM A, KRAWIECKI MADONNA MARIE, PESHEK PETER S, ANDERSON, GEORGE, R., ATWELL, WILLIAM, A., KRAWIECKI, MADONNA, MARIE, PESHEK, PETER, S.
Applicants: PILLSBURY CO, THE PILLSBURY COMPANY
Application year: 1987
Main classification: A23L1
IPC codes: A23G9, A23L1, A23L3, B65D81