Abstract:
A method and apparatus provides infusing marinating liquids into foods in a relatively short period of time to enhance the flavor of said foods. The method uses air pressure above atmospheric to force marinating liquid into the foods. The foods are submerged in the marinade and the air pressure forces the marinade into the submerged foods. Air pressure and time of pressurization is electronically controlled and can be based upon the weight of the food to be marinated. The apparatus includes a sealed vessel for holding the food and marinate and electronic controls that set and manage a pump to control the pressure and duration of pressurization to insure adequate penetration of the marinating liquid into the food.

Description:
FIELD OF THE INVENTION 
     This invention pertains to the field of food preparation. More specifically, a method and apparatus for quickly flavoring foods using marinating liquids is disclosed. 
     BACKGROUND OF THE INVENTION 
     It is common practice to marinate foodstuffs to enhance or change their flavor and to tenderize less expensive cuts of meats. Typically, meat or poultry is placed in a marinating liquid for an extended period of time so that the meat or poultry may absorb the marinating liquid and its flavor. Whereas marinating is a relatively simple process the time it takes for the foodstuff, such as meat, poultry, or vegetables to absorb sufficient quantities of marinating liquid is often a substantially long duration of time. Allowing meat, poultry and vegetables to remain in a marinade for as long as forty-eight hours prior to cooking is a common practice. As an example, Sauerbraten is typically prepared by placing beef bottom round roast, a relatively inexpensive meat, in a marinating liquid for up to 48 hours to flavor and tenderize the meat prior to its being ready for cooking. Very often time does not permit such thorough marinating and the quality and flavor is typically less than what it would have been with proper preparation. 
     Methods of marinating foodstuffs are well known in the art. U.S. Pat. Nos. 4,818,550 and 5,057,332 to Davidson, et al., and U.S. Pat. No. 3,928,634 to Gasbarro, disclose marinating meats and poultry by forming a vacuum (negative pressure differential) to suck the air out of the food that form spaces within the food into which the marinating liquid may enter and fill. Using vacuum techniques, for marinating of foodstuffs, however has disadvantages. 
     First, the greatest possible vacuum that can be achieved results in a pressure differential of one atmosphere—i.e., 14.7 pounds per square inch. To achieve this 14.7 psi pressure differential the vacuum and the vacuum seal must be perfect. As a perfect vacuum is unachievable, and defects in the vacuum seal decrease the ability to maintain the pressure differential, the actual difference in pressure may be significantly less than this greatest possible value. 
     Secondly, atmospheric pressure varies with altitude, and accordingly the greatest possible pressure differential that may be achieved also varies. For example, at sea level, the greatest possible pressure differential achievable is 14.7 psi, whereas, at an altitude of 5000 feet, the greatest possible difference in pressure differential may only be 12 psi; a 20% reduction in pressure. 
     Third, the level of absorption of the marinating liquid into the foodstuff is limited by the pressure differential achieved. As the marinating liquids begins to fill the spaces that are evacuated of air, the liquid filling the spaces in the outer food layer prevents entrapped air from escaping from the center layers of the food. The air thus remains trapped in the center of the food and either greater pressure differentials or longer periods of marinating are necessary to extract this trapped air and thoroughly marinate the foodstuff. 
     Other methods, using positive pressure to infuse liquids into foodstuffs, are known in the art. These methods, however, are more concerned with preservation of food rather than marinating to enhance flavor. U.S. Pat. No. 194,550 to Echart, U.S. Pat. No. 474,446 to Fey, U.S. Pat. No. 550,151 to Averkamp, and U.S. Pat. No. 1,052862 to Trescott disclose methods of using very high pressure over long periods of time to pickle meats and fish for preservation. 
     It would thus be highly desirable to reduce the time required to thoroughly marinate foodstuffs. The apparatus and method disclosed herein not only thoroughly marinates foodstuffs in a fraction of the time typically required for the marinating process, but also provides for greater penetration of the marinating liquid into the foodstuffs. 
     SUMMARY OF THE INVENTION 
     A method and apparatus are disclosed to infuse marinating liquids into foods in a short period of time to enhance or change their flavor, and, in some cases, to tenderize the food. The invention uses a positive pressure differential that causes the marinating liquids to be infused into the food while air trapped in the food is expelled by the entering liquid. Subjecting the foods to a positive pressure differential increases the penetration of the marinating liquid. Increasing either the pressure or the length of time that the positive pressure is applied increases the amount of marinating liquid that is forced into the food. 
     It is the principal object of the present invention to provide a method and apparatus for thoroughly marinating foodstuff in a short period of time. 
     This and other objects and advantages of the present invention will become apparent from the following detailed description taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The advantages, nature and various additional features of the invention will appear more fully upon consideration of the illustrative embodiments to be described in detail in connection with the accompanying drawings. In the drawings: 
     FIG. 1 illustrates a cutaway frontal view of an exemplary embodiment of the invention claimed; 
     FIG. 2 illustrates a side view of the exemplary embodiment of the invention illustrated in FIG. 1; 
     FIG. 3 illustrates a cutaway frontal view of a second exemplary embodiment of the invention claimed; 
     FIG. 4 illustrates a top view of an exemplary embodiment of a marinating container according to invention claimed; 
     FIG. 5 illustrates a side view of a third exemplary embodiment in accordance with the invention claimed; 
     FIG. 6 illustrates a fourth exemplary embodiment of the invention claimed; 
     FIG. 7 illustrates a fifth exemplary embodiment of the invention claim; and 
     FIG. 8 illustrates a side view of the exemplary embodiment of the invention illustrated in FIG.  7 . 
    
    
     It is to be understood that these drawings are for purposes of illustrating the concepts of the invention and are not to scale. It will be appreciated that the same reference numerals have been used throughout to identify corresponding parts. 
     DETAILED DESCRIPTION 
     Referring to FIG. 1, a marinating device  100  comprises a pressure vessel  110  defined by base unit  130  and cover  140 . Pressure chamber  160  is formed when cover  140  is securely placed on base unit  130 . A pump assembly  150 , disposed in base unit  130 , pressurizes chamber  160  by pumping air into chamber  160  through air tubing  170 . Air tubing  170  is in fluid communication with control valve  180  to allow air to enter the chamber  160 . Air control valve  180  when open allows air to enter chamber  160  and when closed seals the chamber to maintain the air pressure at the elevated levels. The elevated air pressure level forces marinating liquid into food placed within chamber  160 . 
     Base unit  130  is defined by lower bottom wall  190 , side walls  200  and upper bottom wall  210 . Base unit  130  may be constructed in a square, rectangular, circular or elongated shape. The specific shape of base unit  130  is not material to the invention claimed and, as will be understood, the performance of the invention is not altered using any one shape over another. In the embodiment illustrated, between upper bottom wall  210  and lower bottom wall  190 , an enclosure is formed for containing pump  150 . Lower bottom wall  190  rests on feet  205  that raise bottom wall  190  slightly above the ground surface. Feet  205  provide for stability of base unit  130  on unleveled surfaces, help to dampen vibrations resulting from operation of pump  150  and allow a space to ventilate pump  150  through open grating  220  in lower bottom wall  190 . 
     Side walls  200  extending upward from lower bottom wall  190  form a container with support surface  230  on the upper edge of side walls  200 . In one embodiment of the invention, annularly disposed along the perimeter of support surface  230  is a generally “U” shaped recess  240  containing sealing ring  250 . Typically sealing ring  250  is constructed as a silicon- or a rubber-based elastic material and is shaped as an O-ring or as a U-ring. Sealing ring  250  fills and closes any gap between cover  140  and base unit  130  at support surface  230  to prevent the escape of air during pressurization. A light coating of olive, vegetable, or corn, oil, may also be spread on sealing ring  250  to form a viscous boundary to enhance the air tight seal formed between cover  140  and base unit  130 . In another embodiment of the invention, not illustrated, upper edge of side wall  200  is a smooth flat surface and sealing ring  250  is annularly disposed along the perimeter of cover  140 . Sealing ring  250  fills and closes any gap that may occur between cover  140  and base unit  130 . 
     Attached to side wall  200  are retaining clamps  260  that engage clasps  270  on cover  140 . The engagement of retaining clamps  260  to clasps  270  securely hold cover  140  in place on base unit  130  and prevents cover  140  from lifting during the pressurization of pressure compartment  160 . 
     In one embodiment of the invention, cover  140  may be completely removable from base unit  130  and is attached to base unit  130  through engagements clamps  260  and clasps  270  located on the opposing sides of base unit  130  and cover  140 . 
     Cover  140 , in the exemplary embodiments illustrated in FIG.  1  and FIG. 2, is hinged to base unit  130  along side wall  200 . In this embodiment, cover  140  has within it air pressure control valve  180 , safety valve  280  and electronic controls  290 . As will be understood control valve  180 , safety valve  280  and electronic controls  290  may also be included within body  130  without altering the performance of the invention. 
     Control valve  180  controls the flow of air from pressure pump  150  into and out of chamber  160 . Air pressure may also be expelled from chamber  160  through control valve  180 . Safety valve  280  prevents pressure within chamber  160  from exceeding known pressure levels by releasing pressurized air from pressure chamber  160  to the surrounding environment when known pressure valves are reached. Pressure safety valves are well known in the art and details of such pressure valves are not disclosed herein. Electronic controls  290  control the operation of the invention by controlling the amount of pressure and the time duration for which the pressure remains in chamber  160 . Electronic controls  290  include preset settings of pressure and time duration for specific foods. Further electronic controls  290  provide the user with the ability to adjust pressure and time independently for personal desires of flavoring or taste. Electronic controls  290  are in communication with pump  150  and control valve  180  to operate pump  150  and control valve  180 . Electronic controls are well known in the art and details of such controls are not disclosed herein. 
     Further illustrated in FIG. 1, air pressure pump  150  is located internal to base unit  130 , between lower bottom wall  190  and upper bottom wall  210 . Typical alternating current(AC) electrical connector  300  extends through side wall  200  to allow for a connection to an electrical source to provide a power source to pressure pump  150  and electronic controls  290 . Whereas an AC electrical source is illustrated in FIGS. 1 and 2, pressure pump  150  and electronic controls  290  may also be energized by a constant electrical source, for example, a battery or a rectified AC source (i.e., an AC adapter). 
     Pressure pump  150  includes an air egress opening that is in fluid communication with control valve  180 , which in this illustrated embodiment is located in cover  140 , through tubing  170 . Tubing  170  preferably is a plastic tubing, however, any number of metal or resin tubing materials may be utilized without any loss of performance of the invention. FIG. 2, which illustrates a cut-away side view of the embodiment of the invention of FIG. 1, depicts a typical arrangement of the fluid connection between pressure pump  150  and control valve  180 . In this exemplary embodiment, tubing  170  is enclosed within side wall  200  and cover  140  and passes through hinge  320  to connect tubing segments in side wall  200  and cover  140 . In another embodiment of the invention, tubing  170  may be external to base unit  130  and covered by a material that is similar to, or different from, that of base unit  130 . In another embodiment of the invention, tubing  170  may also be integrally incorporated into base unit  130  and cover  140  by including a channel within side wall  200  that continues through a similarly constructed channel in cover  140 . 
     The method of the invention is now explained in regard to the operation of the apparatus of FIGS. 1 and 2. Electronic controls  290 , when activated, causes control valve  180  to open and enables air to flow through tubing  170  into sealed chamber  160 . Also started by electronic controls  290 , pressure pump  150  pumps air into air tubing  170  which transports the air into chamber  160 . Air continues to enter chamber  160  and without any means of escaping the air pressure within chamber  160  increases. Electronic controls  290  maintain control valve  180  open and pump  150  operational until the pressure within chamber  160  reaches a desired level of pressure, or for a fixed time for which a know and desired level of pressure may be achieved. The desired level of pressure as noted previously is set by the user based on level of marinating desired. The level of pressure, and duration, may be set automatically in electronic controls  290  through a single instruction, that sets known pressures and durations concurrently, or may be set individually in electronic controls  290  to meet particular levels of marinating. In one embodiment of the invention, the pressure and time duration may be set as a function of the weight of the food to be marinated. In this embodiment, electronic control means  290  communicate with a scale (not shown) that measures the weight of the foodstuffs placed in chamber  160 . 
     After the desired pressure is attained, electronic controls  290  direct control valve  180  to close and pressure pump  150  to cease operation. The accumulated pressure in chamber  160  remains at the desired level for the duration of the desired time period during which time the marinating liquids are infused into the enclosed foods. In one embodiment of the invention, the desired level of pressure may be determined by computing the time necessary for pump  150  to supply sufficient amount of air to increase the pressure in chamber  160 . This time may be incorporated into the programming of electronic controls  290 . In another embodiment of the invention electronic controls  290  may also determine when the desired pressure is achieved by receiving feedback signals from pressure sensors (not shown) incorporated into chamber  160 . 
     An advantage of using positive pressure in the marinating process is that sophisticated air sealing means are typically not necessary. In cases where the air seal is not perfect, losses in air pressure can be accommodated by the continued operation of pump  150 . In this case, electronic controls  290  may intermittently restart pump  150  to increase air pressure to compensate for air losses through the seal. 
     At the conclusion of the desired time period, electronic controls  290  direct control valve  180  to open and the accumulated pressure in chamber  160  is released. In one embodiment of the invention, the air pressure may be released by passing the excess air through tubing  170  and pump  150  into grating  220 . In another embodiment of the invention the air pressure may be released into the surrounding atmosphere through control valve  180  or a second port valve (not shown), which is also controlled by electronic controls  290 . As there is no heat employed in the invention the release of pressurized air into the surrounding environment does not introduce a danger to the user, as, for example, the release of pressure from a pressure cooker. 
     After the air pressure in chamber  160  returns to a normal atmospheric pressure, cover  140  may be unclasped from base unit  130 , the marinated foods removed, and prepared for cooking, if cooking is required. For example, raw vegetables may be marinated, to change their flavor or color, and then may be served without any further preparation. 
     Examples of the use of the invention are now presented to illustrate the advantages in marinating achieved through the method of the invention. Typical home marinating technique simply consists of preparing a marinating solution and submerging the foodstuff into the solution for some period time. The time period is not known precisely because different cuts of meat, or fish, or poultry or vegetable all have different rates of absorption. Generally, the longer the foodstuffs remain in the marinating solution, the more marinating flavor is absorbed. As an example, consider a 3 pound beef bottom round roast placed in a marinating solution for 48 hours increased in weight by approximately 4%. This increase in weight is expected as the marinating liquid is absorbed into the meat. 
     Using the method of the invention disclosed herein, a similar quantity of meat subjected to a pressure of 30 psig (pounds per square inch gauge) for 10 minutes experienced an increase in weight of 10%. In this case significantly more marinating solution (and flavor)was absorbed by the meat in significantly less time. 
     As can be understood, the method of the invention is not only applicable to meats but can be used for a large number of foods. Further, the method is not limited to the pressure or time durations expressed in the above exemplary examples, but can be varied over significant pressures and times. Examples of foods prepared in accordance with the method of the invention are presented in Tables 1 through 3. 
     Table 1 presents the percentage weight increase experienced by baked potatoes for different combinations of pressure and duration of pressurization. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Percentage Increase in Weight of Baked Potato With Marinating 
               
             
          
           
               
                   
                 1 Minute 
                 5 Minutes 
                 10 Minutes 
               
               
                   
                   
               
             
          
           
               
                   
                 15 psig (approx. 2 atm.) 
                  0 
                  0 
                 17 
               
               
                   
                 20 psig 
                 13 
                 24 
                 44 
               
               
                   
                 30 psig (approx. 3 atm.) 
                 20 
                 44 
                 56 
               
               
                   
                   
               
             
          
         
       
     
     Table 2 presents the percentage weight increase experienced by pork chops for different combinations of pressure and duration of pressurization. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Percentage Increase in Weight of Pork Chop with Marinating 
               
             
          
           
               
                   
                 1 Minute 
                 5 Minute 
                 10 Minute 
               
               
                   
                   
               
             
          
           
               
                   
                 15 psig (approx. 2 atm.) 
                  0 
                 10 
                 10 
               
               
                   
                 20 psig 
                 10 
                 20 
                 23 
               
               
                   
                 30 psig (approx. 3 atm) 
                 14 
                 25 
                 31 
               
               
                   
                   
               
             
          
         
       
     
     Table 3 presents the percentage weight increase experienced by zucchini for different combinations of pressure and duration of pressurization. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Percentage Increase in Weight of Zucchini with Marinating 
               
             
          
           
               
                   
                 1 Minute 
                 5 Minute 
                 10 Minute 
               
               
                   
                   
               
             
          
           
               
                   
                 15 psig (approx. 2 atm.) 
                 00 
                 30 
                 38 
               
               
                   
                 20 psig 
                 15 
                 36 
                 42 
               
               
                   
                 30 psig (approx. 3 atm) 
                 22 
                 49 
                 56 
               
               
                   
                   
               
             
          
         
       
     
     Of course, it should be understood that Table 1-Table 3 only present exemplary values of pressure and time of pressurization and that a continuum of such values may be realized. 
     In another embodiment of the invention, illustrated in FIG. 3, non-porous container  340  is sized to fit within chamber  160 . Container  340  is used to hold the marinating liquid and foodstuff. In this embodiment only container  340  is in contact with foods and liquids. This provides for faster and simpler cleaning of the unit but otherwise does not alter the concept of the invention. Container  340  may also be divided into individual compartments, as illustrated in FIG.  4 . It should be understood that this illustration is merely an exemplary example and container  340  may be of a square rectangular, circular, or elongated shape to accommodate the shape of chamber  160 . In this embodiment, the individual compartments are isolated by non-porous material wall  350  from the other compartments within container  340 . Container  340 , sectioned in this manner, allows for different flavoring or marinating liquids and different foods to be placed in the different compartments to marinate a host of different foods with different flavorings at the same time. As is illustrated container  340  is divided into 3 compartments, however, it should be understood that this is for illustration only, and any number of compartments may be formed. 
     In another embodiment of the invention, container  340  may form an integral part of providing for pressurized chamber  160 . In the exemplary embodiment illustrated in FIG. 5, supporting lip  500  of container  340  rests on support surface  230  of base unit  130 . Annularly disposed within supporting lip  500  is a U-shaped groove  510  capable of engaging cover  140  such that the edges of cover  140  are contained within U-shaped groove  510 . In still another embodiment, as illustrated in FIG. 6, U-shaped groove  510  may contain an O-shaped sealing ring  250  that engages cover  140  to form an air-tight seal. A light covering of oil, such as olive or vegetable or corn oil, may be spread on O-shaped sealing ring  250  and supporting lip  500  to form a viscous boundary to enhance the air tight seal of chamber  160  formed between cover  140  and base unit  130 . 
     In still another embodiment of the invention, as illustrated in FIG. 7, and similar in design to a microwave oven unit, air tight chamber  160  is created between base unit  130  and door  700 . Sealing means, similar to those described in regard to FIGS. 1,  2 ,  5  and  6 , within door  700  or opening  710  of base unit  130  are used to prevent pressurized air from escaping from chamber  160 . In this embodiment, a container, similar to that illustrated in FIG. 4, is used to retain food and marinating liquid. The container may be a container of any shape and size and need not fit chamber  160  in a manner as container  340  fits chamber  160 . In this embodiment, door  700  may be securely held to base unit  130  by clamps, as illustrated, or locking screws. Other mechanisms of securely retaining door  700  to base unit  130  are well known in the art and need not be enumerated herein. FIG. 8 depicts a side view of the invention depicted in FIG. 7 wherein pump  150  is illustrated deposed at the rear of base unit  130  and tubing  170  extends upward toward control valve  180 . In this embodiment of the invention, control valve  180  is illustrated located on a side of chamber  160 , however, control valve  180  may also be located on the top or back surface of chamber  160 . 
     CONCLUSION 
     A novel method and apparatus of the marinating of foodstuffs have been presented that enable a user to quickly marinate a variety of foodstuffs to enhance or change their flavor, and to tenderize meats in particular. Employing positive pressure the ability to use greater pressure differentials aids in infusing marinating liquids more thoroughly and uniformly through out the food in a shorter period of time. 
     Numerous modifications and alternative embodiments of the claimed invention will be apparent to those skilled in the art in view of the foregoing description. The examples given herein are presented to enable those skilled in the art to more clearly understand and practice the invention claimed. The examples should not be considered as limitations upon the scope of the invention, but as merely representative of the use of the invention. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention and is not intended to illustrate all possible forms thereof. It is also understood that the words used are words of description, rather that limitation, and that details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications which come within the scope of the appended claims is reserved.