PROCESS FOR INCORPORATING ASPARTAME INTO EXTRUDED PRODUCTS

Abstract: Dry comestibles, such as cereal products and baked-type goods having an L-aspartic acid sweetening derivative distributed substantially uniformly throughout the comesti­ ble as a substitute for sugar or other sweeteners, are obtained by combining the L-aspartic acid sweetening derivative, a pH adjuster, water, and the remaining dry ingredients of the comestible to form a dough, extruding the dough through an extruder die plate, cutting the extruded product into pieces, and optionally reducing the moisture content of the pieces by conventional means like drying or toasting. The most feasible method of combining the ingredients is to separately feed: a) an aqueous solution of the sweetening derivative having a pH adjusted to about 1.0-7.0, preferably 2.0-3.0, and b) a preblended mixture of the remaining dry ingredients to the extruder wherein they are admixed to form a dough. Decomposition of the L-sapartic acid sweetening derivative during processing is minimized by controlling the pH of the sweetener solution, and the exposure time of the sweetener to high temperatures throughout the process for producing the dry comestible. The extruded dry baked comestibles are highly palatable, do not look sugar coated, do not contain localized concentra­ tions of the L-aspartic acid sweetening derivative and are shelf stable for extended periods of time.

Description: BACKGROUND OF THE INVENTION 1. Field of the invention This invention relates to a process for incorporating an Laspartic acid sweetening derivative into an extruded dry comes ii tible. This invention also relates to extruded dry comestibles having an L-aspartic acid sweetening derivative which is distributed substantially uniformly throughout the extruded product. 2. Background of the Invention L-aspartic acid sweetening derivatives, typical of which is ii the dipeptide N-L-aspartyl-L-phenylalanine methyl ester (aspar- tame) are potent sweetening agents which have been proposed for Ii il use as nutritive sweeteners for a wide range of foodstuffs. Fon example, in U.S. patent 3,799,918 alpha-aspartyl-alpha-alkyl aliphatic amino acid dipeptides are disclosed as sweetening agents for milk products, confections; bakery products, cereal, carbo nated beverages, syrups, fruits, juices, and the like. The sweetness of the L-aspartic acid derivatives has been estimated as about 100 to 200 times greater than the sweetness of of sucrose on a weight-to-weight basis. However, many of the 51 il-aspartic acid derivatives, such as aspartame, are prone to under jgo a loss of sweetness in the presence of moisture, rendering tnetn essentially non-functional in many food applications. Many processes to stabilize these L-aspartic acid derivatives in a form whereby they do not undergo degradation with accompanying loss of sweetness under storage conditions are known in the art. These processes typically involve encapsulating or coating particles of the L-aspartic acid derivative with various edible coating mate rials followed by drying and granulation. For example, in U.S patent 3,962,468, particles of L aspartic acid derivatives are stabilized in a dry fixation by causing a slurry-forming level of undissolved hydrated particles of the sweetening compound to be dispersed in an aqueous dextrin solution as discretely distributed undissolved particles and dry ing the dispersion to encapsulate the particles of the L-aspartic acid derivative in the dextrin. In D.S. patent 4,004,039, L-aspartyl-L-phenylalanine methyl ester crystals are stabilized into a particulate form so as to be free-flowing with other powderous materials. The stabilization process involves admixing the crystals with a matrix forming material such as dried coffee extract, whey, low dextrose equivalen starch polymers and protein extracts, heating the admixture to form a melt, in which the ester crystals are discretely distribute calendering the melt between two rollers to submerge the crystals in the melt, cooling the melt, and then granulating the product to produce particles which encapsulate the crystals distributed therein. In lieu of the roll-fusing operation, other means, such as extrusion apparatus, capable of generating frictional heat to effect fusion through the work generated by the auger, can be used to effect fusion. Roller fusing is preferred because it is easier to control the moisture content of the mi. In U.S. patent 3,934,048, dipeptide sweeteners such as L aspartyl-t-phenylalanine methyl ester are imparted with a satis factory rate of solubility and storage stability due to low hygroscopicity by co-drying a solution of the dipeptide and an edible, bland, low calorie polysaccharide. The processes disclosed in U.S. patents 3,962,468, 4,004,039 and 3,934,048 each relates to the production of powdery or granular compositions. This type of composition is also dis closed in the above-mentioned U.S. patent 3,799,918. In the latte patent, a dry sweetening product is produced by combining a mix ture of an alpha-aspartyl-alpha-alkyl aliphatic amino acid dipepti and hydrolyzed cereal solids having a low dextrose equivalent with water and then spray drying. - Use of the L-aspartic acid derivatives directly or in a dry stabilized form as a replacement for sugar in foods has been hindered by a non-uniform sweetening response, such as hot spots1 attributable to high concentrations of the sweetener at discrete locations on the foodstuff. The low solubility of the L-aspartic acid derivatives such as aspartame(1% in water at room tempera ture), has been indicated as a contributor to the non-uniformity of topical application of the derivatives on the surface of the food stuff. Another problem which has limited the use of L-aspartic acid derivatives as a substitute for sugar in certain foods is their thermal instability. For example, aspartame is a synthetic sweet ener recently approved by the Food and Drug Administration. It Idoes, however, have limited use due to its potential to decompose upon exposure to heat into diketopiperazine (DKP), for example, resulting in a reduction of sweetening power. Aspartame, as well as other heat sensitive L-aspartic acid derivative sweeteners, have therefore been considered unsuitable as a replacement for sugar in products that are neutral in reaction or which must be exposed to high temperatures during processing. Unfortunately, many of the foods that could benefit from a reduction in sucrose levels, such as baked goods or presweetened cereals fall into these categories. To sweeten baked goods or ready-to-eat cereal products with aspartame, resort has been made to coating processes wherein the aspartame is not subjected to conventional baking temperatures and times. In U.S. patent 3,955,000 cereal products, baked goods, such as pastry mixes, and confectionary foodstuffs intended to be sweetened with the sensation of sucrose are coated with an Laspartic acid derivative, such as the methyl ester of L-aspartyl L-phenylalanine, The derivatives are admixed in aqueous suspensio with hydrolyzed amylacous derivatives comprising predominantly oligosaccharides solids having a low dextrose equivalency, of abou less than 30, and applied as a coating solution to the comestible. A A coating of the dried solution, it is disclosed, smoothes out the taste impact generated by any sweetening imbalance attributable to the incomplete solution of the L-aspartic acid derivative or non uniformity of its dispersion. The uniform distribution of sweet ness, such that when the foodstuff is eaten "hot spots" are minimized, is attributed principally to the starch hydrolyzate. In the process of U.S. patent 3,955,000, the coating solu tion is maintained at a temperature below 200OF so as to have the sweetening derivative dispersed therein as undissolved hydrated particles. The solution is applied to the foodstufr ry tXomizatior or other spray techniques. The coated comestible, it is disclosed is dried at product temperatures which do not exceed 200OF in orde to assure that the sweetening compound is not degraded while the coated comestible is dried to a stable moisture content of below about 88. The coating process of U.S. patent 3,955,000 results in pro ducts which have a frosted or glazed appearance to make the produc look sugar coated. Other substances, such as fats and starches, i is disclosed, can be incorporated in the coating to create a dull or crystalline appearance suggestive of other sweetened cereal applications. However, the appearance of a sugar coating, whether glazed or dull is associated with an undesirable amount of sugar by many consumers. Further, the dextrins and other additives in the coating increase the calorific value of the foodstuff. The coating, when applied to a cereal product, such as corn flakes, dissolves in milk which reduces the sweetness of the product often to an undesirable extent. The coating process does not permit combining of all the ingredients in one operation because the coating components must be applied to the formed product. Additionally, the coating process of U.S. patent 3,955,000 does not result in a final product having the sweetener distributed substantially throughout the product. Unexpectedly, with the extrusion process of the present invention, the L-aspartic acid sweetening derivative can be exposed to typical baking temperatures and times without substantial decomposition. It is not known why high temperatures can be used in an extruder. It is believed to be a combination of the time, temperature, and pressure profiles of the extrusion process, for a given method of combining the sweetener with the other ingredients |The stability of aspartame in solution is a function of pH, time of exposure to high temperatures, and temperature. By controlling the detrimental effects of pH and exposure time, the acverse effects of higher temperatures during processing of a variety of baked-type goods and cereal products is minimized by the extrusion process of the present invention. The process for making the extruded dry comestibles is economical, does not involve a separate coating step for incorporatin the L-aspartic acid sweetening derivative into the product, achieves substantially uniform distribution of the sweetener throughout the dry comestible, and minimizes the decomposition or carmelization of the sweetener during production of the dry comestible. The process of the present invention permits the use of aspartame as a replacement for sugar in foods that are neutral in reaction or which must be exposed to high temperatures during processing. The use of dextrins, which increase the calorific value of the comestible, to obtain uniform distribution of the aspartame as in U.S. patent 3,955,000, is not needed in the process of the present invention. The invention provides inter alia an extruded baked dry comestible, such as a ready-to-eat cereal or a baked-type good having a L-aspartic acid sweetening derivative, such as N-L-aspartyl-Lphenylalanine methyl ester (aspartame) distributed substantially uniformly throughout the dry comestible. The extruded baked products of the present invention do not look sugar coated, have a pleasing texture, and do not contain "hot spots" due to high concentrations of the sweetener at discrete locations inW the zomest- ible. A uniform sweetening response is exhibited throughout the products and they are shelf-stable SUMMARY OF THE INVENTION According to one aspect thereof the ivention provides a method @@ making extruded dry baked comestibles, su@@ kurll d S t e, products dlid bjked-t7 goods having an L-aspartic acid sweetening derivative, such as Laspartyl-L-phenylalanine methyl ester (aspartame) distributed substantially uniformly throughout the dry comestible. Decomposition or carmelization of the L-aspartic acid sweetening derivative during processing is minimized by controlling the pH of the sweetener solution used in the extrusion, and the exposure time of the sweetener to high temperatures during production of the dry comestible. Other aspects of the Invention are set out in the claims. Substantially uniform distribution of the sweetening deriva tive throughout the dry comestible is best achieved by preblending all flours, salts, emulsifiers and other dry ingredients of the comestible and then coextruding the pre-blended mixture with an aqueous solution of the L-aspartic acid sweetening derivative. Due to the use of small quantities of the potent L-aspartic acid sweetening derivatives, the sweetener is preferably fed tothe extruder as an aqueous solution to reduce physical losses of the sweetener and to reduce the time needed to achieve substantially uniform distribution of the sweetener through the comestible. An acidic solution of the L-aspartic acid sweetening derivative is used to obtain maximum solubility With minimal decomposition. Pharmaceutically acceptable pH-adjusters are used to obtain a sweetener solution having a pH of about 1.0-7.0. For aspartame, a pH of about 2.0-3.0 is optimal. The use of an extruder permits rapid, homogeneous mixing of all ingredients thereby reducing the exposure time of the Laspartic acid derivatives to high processing temperatures. Additionally, upon the exiting from the extruder, the extruded product expands thereby reducing or eliminating the amount of subsequent drying needed to achieve a desired moisture level in the dry comestible. The resulting extruded drv comestibles ar: highly palatable, shelf-stable, do not look sugar coated, and do not contain localized concentrations or "hot spots" of the Laspartic acid sweetening derivative. DETAILED DESCRIPT1ON OF THE PREFERRED EM3VDl! TS The L-aspartic acid sweetening derivative used in the present invention is preferably L-aspartyl-I-phenylalanine methyl ester (aspartame) because of its recent approval for use in foods by the Food & Drug Administration. However, other L-asDartic acid sweetening derivatives, such as those disclosed in U.S. patent 3,955,000 at column 3 line 63 to column 4 line 35, can also be used in producing dry extruded comestibles in accordance with the present invention. The aqueous solution of the L-aspartic acid sweetener derivative is preferably prepared by first dry blending the sweetener with a pH-adjuster. The dry blend is then adder to water to form the solution. The water may be preheated to increase the solubility of the sweetener. Dry blending assures that the dry sweetener is added in an amount such that it is dissolved in the pH adjusted aqueous solution. The concentration of the sweetener in the pH adjusted solution is typically about 0.1% to about 10% by weight of the final solution, depending upon solubility of the sweetener in water. In the case of aspartame, the concentration is about 0.1% to about 10%, preferably about 2% by weight aspartame based upon the weight of the final solution. The pH adjuster is added in an amount which results in an acidic pH which increases the solubility and of the sweetener in the aqueous solu- tion. The pH used will depend upon the specific L-aspartic acid sweetener but it is generally in the range of about 1.0 to about 7.0. It has been found tnat at a pH of about 2.0 to about 3.0, aspartame exhibits optimal stability and solubility in the aqueous solution. At lower pHs, particularly less than about 2.0, the stability of aspartame decreases. At a pH above about 7.0 the solubility of the aspartame decreases to an unsuitable level. The temperature of the water to which the dry blend of sweetener and pfl adjuster is added should be sufficiently high so that the preblend completely or substantially completely dissolves in water. However, it should be low enough so as not to adversely affect the stability of the sweetener. Typically, the water temperature should be in the range of from about 40"F to about 210 oF. For aspartame, water temperatures of from about 40 to about 2100F, preferably about 700F to about 1600F, most preferably about 850F to about 1000F are used to dissolve the aspartame with out substantial decomposition. By maintaining the aqueous solution of the sweetener at a temperature within the above ranges1 crys tallization of the sweetener from the solution prior to and/or during feeding of the solution to the extruder can be avoided. Use of a solution as opposed to an aqueous slurry or dis persion of the sweetener, facilitates handling by reducing equip ment clogging and reduces the need for special equipment for handling slurries. Additionally, the lower viscosity of the solution and the larger quantity of solution (for a given amount of sweetener) results in the attainment of a substantially uniform distribution of the sweetener faster than could be obtained if a slurry were used. The The L-aspartic acid sweetening derivative used to produce the aqueous solution used in the present invention is preferably in pure form. While L-aspartic acid sweetening derivatives, which have been coated or encapsulated with edible materialstc improve their flow characteristics and/or stability can be used, they are not preferred because of increased cost. Additionally, the coatings often lower the dissolution rate and increase the calorific value of the foodstuff unnecessarily. The preferred pH adjusters for use in the present inventio are a citric acid and sodium citrate buffer system and malic acid. however, other known pharmaceutically acceptable inorganic or organic acids or buffering systems which do not adversely affect the taste of the dry comestible can also be used. The organic acids are preferred organoleptically over the inorganic acids. Exemplar of other suitable organic acids are fumaric acid, adipic acid, tartaric acid, and mixtures thexeof. Malic acid is the preferred organic acid because it imparts a pleasant taste to the dry comestible. Exemplary of other suitable buffering systems are any of the above organic acids in combination with an alkali metal salt thereof. The aqueous solution of the sweetening derivative is fedto the extruder at a rate which provides a level of acceptable sweetness, as determined by a professional taste panel, in the finished dry comestible. For aspartame, a solution feed rate which would provide an aspartame level of about 0.001% to about 1.0%, preferably 0.10% to about 1.08 by weight of the finished extruded product, provides an acceptable sweetness level. While some of the aspartame may decompose during processing, depending on extruder conditions, the remaining amount should provide an acceptable leve of sweetness. It has been found that under the same processing conditions, higher levels of sweetness can be obtained with the aspartame than with sugar without undesirable browning, and with out an undesirable increase in hardness or decrease in size of the finished product which are caused by carmelization of the sugar. A typical formulation for the dry comestible contains about 65% to about 90% by weight flour, about 5% to about 30% by weight water, about 1% to about 3% by weight emulsifiers, and about 18 to about 3% by weight salts. Other ingredients known in the cereal and bakery art, for providing suitable texture, flavor, preserva tion, color and the like of the finished dry comestible, can also be included in amounts conventionally used in the art. Any known formulations for the production of drycomestiblEs can be used in the extrusion process of the present invention pro vided that the dough which is formed by admixing the dry and wet ingredients with the sweetener of the present invention is soft enough to be extruded. The moisture content of the mixed dough should be high enough to assure dough softness and to assist in the expansion or puffing of the dough as the dough exits from the ex truder. If the moisture content of the dough is too high, higher temperatures and longer times would be needed. to obtain a final product having an acceptable level of moisture. Unnecessary de composition of the sweetener could occur as a result of the longer exposure to higher processing temperatures. Suitable moisture con tents of the mixed dough are in the range of about 5% to about 30% preferably about 10% to about 20% by weight of the mixed dough. When known formulations which contain a sweetener component are used, the sweetener component is replaced in whole or in part by the L-aspartic acid sweetening derivative. Complete replacement Is preferred so as to reduce the cariogenicity of the finished pro-; duct to the maximum extent possible. The L-asDartic acid seeten- ing derivatives can be used in combination with other sweeteners, natural or artificial, to provide a level of acceptable sweeteness. Exemplary of the sweeteners are saccharin, cyclamates, stevioside, sucrose, sorbitol, sucrose, glucose, and the like. Exemplary of the dry comestibles which can be produced in ccordance with the present invention are cereal products such as re-sweetened ready-to-eat expanded cereals, flaked cereals (formed from pellets), instant hot cereals, and bakery-type products such as sweet snacks, expanded cookie-like products, sweetened crisp reads, wafer cookies, ice cream cone or sandwich components and onfectionary components. The dry ingredients are preferably preblended in a blender uch as a ribbon blender, a v-blender, a zig-zag blender, or a Ho art blender, and then fed to the extruder via a hopper. The aqueous sweetening solution is separately fed to the extruder, preferably by means of a positive displacement pump. The aqueous solution of the sweeter is admixed with the dry ingredients of the formulation by means of the screw conveyer of the extruder. he screw forces the dough through a die to form the desired shape. The extruded material is then cut into pieces. In the extruder the temperature during mixing of the aqueou solution and the preblended dry ingredients should be about 400F to about 2100F for residence times of about 2.0 minutes to about 02 minutes. The temperature at the exit of the extruder is maintained sufficiently high so as to enable moisture reduction, baking and expansion of the mixed dough as it exits the extruder. Generally, the temperature at the exit end of the extruder should be about 2100F to about 4000F. The residence time should be long enough to allow baking of the dough. However, the residence time should be sufficiently short so as to avoid decomposition of the sweetener The residence time should generally be less than or equal to about 4.0 minutes, preferably less than about 2.0 minutes, more preferably less than about 1.0 minutes, most preferably less than about 0.8 minutes. Typical residence times range from about 4.0 minutes down to about 0.2 minutes, preferably from about 2.0 minutes down to abort 0.3 minutes, more preferably from about 1.0 minutes down to about 0.35 minutes, most preferably from about 0.80 minutes do to about 0.40 minutes. The pressures used in the extruder are those conventionally used in the production of expanded or puffed extruded dry comestibles and range generally from about 400 p.s.i.g. to about 4000 p.s.i.g. The mixed dough is, accordingly, typically subjected to a pressure drop of about 400 to 4000 p.s.i. as it exits from the extruder. Substantially all of the aspartame contained in the dough prior to baking is retained in the extrusion process of the presen invention. Depending upon extruder processing conditions, retention levels of at least 90% by weight and of at least 95 % by weight, based upon the amount of aspartame prior to baking can be achieved. It is believed, however, that flavorings, such as honey, cinnamon, and chocolate, have a tendency to degrade aspartame. If a flavoring causes decomposition to occur so as to result in an unacceptable sweetness level, higher initial aspartame levels could be used. Feeding the L-aspartic acid sweetening derivative as an acidic aqueous solution to the extruder and combining the sweetener solution with the other ingredients of the dry comestible in the extruder, has been found to be the most feasible method of combining the ingredients. However, other methods of combining the ingredients can be used to achieve a level of acceptable sweetness in the finished dry comestible For example, the aqueous sweetener solution, 'containing the pH adjuster, can be premixed with some or all of the dry ingredients before feeding to the extruder. Blenders conventionally used in the food industry, such as a Hobart blender, can be used to form the premix. The mixing should be carried out long enough to obtain substantial homogeneity and at a temperature which minimizes decomposition of the sweetener. Another method is to admix the sweetening derivative in dry form with the dry ingredients of the comestible to form a preblend, and to feed the preblend to the extruder for mixing with water. The pH adjuster can be in the dry premix or dissolved in the water. A disadvantage of admixing the sweetening derivative in dry form with the dry ingredients is that loss of the sweetener due to dusting tends to occur. Additionally, obtaining substantially uniform distribution of the sweetener throughout the remaining dry ingredients and during extrusion is more difficult because of the relatively small quantity of the dry sweetener. The temperatures, residence times, and pressures used in the extruder, when combining the ingredients by these methods, should generally be within the above ranges. Depending upon the temperature and the degree of mixing achieved outside of the extruder, other temperatures and residence times may be needed to achieve minimal sweetener decomposition and/or satisfactory moisture levels in the extruded product. Extruders known in the baking art for the production of expanded or puffed dry cereals can be used in the present invention. However, a twin screw extruder, such as that manufactured by Creusot-Loire is preferable for easier control of mixing of the dough and moisture contents of the extruded product. Shorter residence times of portions of the dough mass are needed with the twin screw extrudor than with a single screw extruder to obtain substantial homogeneity of the dough and substantially uniform !distribution of the sweetening derivative throughout the dough and extruded product. Moisture levels can be adjusted to any level with either the twin or single screw extruder by controlling the residence time, the temperatures, and the pressure in the extruder. It is preferable to reduce the moisture level to about 0.5-15E, more preferably to about 4-12% by weight water, based upon the weight of the extruded dry product, so as to improve the flavor of the final product. Subsequent drying of the extruded product, in a tunnel dryer or other bakery-type dryer, can be used to achieve a moisture content within the above ranges. By using different extruder die plates and settings, a variety of shapes for the finished product can be obtained. Suit able shapes are cylindrical, O-shaped, rectangular, numerically shaped, letter-shaped, and the like. The extruded product can be cut by methods known in the art to obtain flakes, buts, and other bite-size configurations known in the cereal art or to obtain wafers, cookie-like shapes and snack food-like shapes, for example. Suitable cutters are rotary and reciprocating cutters. The present invention is further illustrated in the follow ing examples. All percentages, parts and proportions are by weight and all temperatures are in OF unless otherwise indicated: EXAMPLE 1 In this example, the dry ingredients for a cereal product, except for the sugar, are used. The dry ingredients and their relative amounts are: INGREDIENT POUNDS Wheat whet Flour 130 Oat Flour 35 Corn Flour 25 Brown Rice Flour 5 Malt Flour 5 Salt 5 Emulsifiers 1 TOTAL 206 An aqueous L-aspartic acid sweetener solution is then prepared by dry blending citric acid, sodium citrate and aspartame and adding the preblended mixture to 900F water to form a solution The citric acid and the sodium citrate are used in amounts necessary to obtain a 0,1M citric acid concentration and a 0.1M sodium citrate concentration. The amount of aspartame used was sufficien to obtain a solution containing 2% aspartame by weight, based upon the weight of the solution. The pH of the solution was 2.7. The remaining dry ingredients were dry-blended in a ribbon blender for 20 minutes at a speed of 30 r.p.m. The preblended mixture of the dry ingredients were fed in a twin screw C-L extruder at a rat of 5 pounds per minute. The sweetener solution was then separately fed to the extruder at a rate of 175 grams/minute. The sweetener solution and the dry blended ingredients were admixed in the extruder at a temperature of about 140OF for a residence time of 0.5 minutes to form a dough. The dough was extruded at a temperature of about 3500F for a residence time of 0.5 minutes and a pressure of 2200 p.s.i.g. through a figure "8" shaped extruder die plate down to atmospheric pressure, and then cut into bite-size pieces on a rotary cutter. The finished product was found to have a pleasant taste. The product was analyzed by high performance liquid chromatograph The aspartame was found to be present in the finished product at a level of about 95% by weight of the originally added aspartame. EXAMPLE 2 Example 1 is repeated except that malic acid is substitute for the citric acid and the sodium citrate. The malic acid is used in an amount which is necessary to obtain a O.18N malic acid concentration. The pH of the solution was 2.4. The finished product was found to have a pleasing taste. The product was analyzed by high performance liquid chromatography The aspartame was found to be present in the finished product at a level of about 95% by weight of the originally added aspartame.

Claims: CLAIM. 1. A process for producing a dry comestible which is sweetened with an L-aspartic acid sweetening derivative comprising admixing an aqueous solution of the L-aspartic acid sweetening derivative having a pH of about 1.0 to about 7.0 with a preblend of the dry ingredients of the comestible to form a dough, extruding the dough, and cutting the extruded product into pieces. 2. A process as claimed in claim 1 wherein said aqueous sweetening solution and said preblend are admixed in the extruder. 3. A process as claimed in claim 2 wherein the L-aspartic acid sweetening derivative is L-aspartyl-L-phenylalanine methyl ester. 4. A process as claimed in claim 2 or 3 wherein the concentration of said sweetening derivative in said solution is about 0.1% to about 10% by weight of the solution. 5. A process as claimed in claim 4 wherein the temperature of said aqueous sweetening solution is about 400F to about 2100F. 6. A process as claimed in claim 1 wherein the concentratior of said sweetening derivative and the temperature of said sweeten 1 ing solution are insufficient for crystallization of the sweetener ing derivative. 7. A process as claimed in claim 1 wherein said sweetening solution contains a pharmaceutically acceptable pH adjuster to maintain the pH in the range of about 1.0 to about 7.0. 8. A process as claimed in claim 7 wherein said pH adjuster is an organic acid or an organic acid and an alkali metal salt thereof. 9. A process as claimed in claim 8 wherein said cH adjus- ter is a citric' acid/sodium citrate buffer system or malic acid. 10. A process as claimed in claim 3 wherein said admixing to form said dough is at a temperature in the range of about 40"F to about 2100F. 11. A process as claimed in claim 10 wherein said dough is extruded at a temperature of about 210OF to about 4000F. 12. A process as claimed in claim 2 wherein said extruder is a twin screw extruder. 13. A process as claimed in claim 3 wherein the extruded product is cut into pieces and then the moisture content is reduced to about 0,58 to about 15% by weight of the finished product 14. A process as claimed in claim 12 wherein the moisture content of the extruded product is less than about 15% by weight of the extruded product. 15. A process as claimed in claim 3 wherein said dough is extruded at a temperature which is sufficient to dry said dough to a moisture content of less than about 15% by weight of the extruded product. 16. A dry comestible containing an L-aspartic acid sweetening derivative distributed substantially uniformly throughout th comestible obtained by the process of claim 1, 3, 13, or 14. 17 A dry comestible as claimed in claim 16 wherein the amount of said sweetening derivative is about O.001% to about 1.08 by weight based upon the weight of the finished product. 18. A dry comestible as claimed in claim 17 which is a cereal product 19. A dry baked comestible comprising an L-aspartic acid sweetening derivative distributed substantially uniformly throughout the comestible, the amount of said sweetening derivative being about 0.001% to about'l,0e by weight of the dry comestible. 20. A dry comestible as claimed in claim 19 which is a cereal product. 21. A dry comestible as claimed in claim 19 wherein said sweetening derivative is L-aspartyl-L-phenylalanine methyl ester. 22. A dry comestible as claimed in claim 21 which is in the shape of a figure eight. 23. A process for producing a dry comestible which is sweetened with an L-aspartic acid sweetening derivative comprisinç a) a) combining the sweetening derivative, a pH adjuster, water, and the dry ingredients of the comestible to form a dough having the sweetening derivative distributed sub stantially uniformly throughout the dough, b) extruding the dough to bake and expand it, and c) cutting the extruded product into pieces. 24. A process as claimed in claim 23 wherein said combining step comprises admixing the sweetening derivative with said pH adjuster and water to obtain an aqueous sweetener solution having a pH in the range of about 1-7, and admixing the aqueous sweetener solution with the dry ingredients. 25. A process as claimed in claim 24 wherein the aqueous sweetener solution and the dry ingredients are admixed prior to being fed to the extruder. 26. A process as claimed in claim 24 wherein the sweetener derivative and the dry ingredients are preblended and the preblend and water are separately fed to the extruder to form said dough. 27. A process as claimed in claim 26 wherein the pS adjuster is included in the prebend, 22. 28 A process as claimed in claim 24 wherein said sweetening derivative is N-L-aspartyl-L-phenylalanine methyl ester and said pH is in the range of 2.0-3.0. 29. 29. A process as claimed in claim 25 wherein said dough is formed in the extruder. 30. A process as claimed in claim 1, 3, 11, 25 or 28 wherein the dough is baked at the exit end of the extruder and upon exitin from the extruder the baked dough is subjected to a pressure drop of about 400 p.s.i. to about 4,000 p.s.i. to expand the baked dog . 31. A dry comestible containing an L-aspartic acid sweetenincr derivative distributed substantially uniformly throughout the comestible obtained by the process of claim 30. 32. A dry comestible as claimed in claim 31 which is a cereal product. 33. A process as claimed in claim 30 wherein the amount of the sweetening derivative in the baked dry comestible is at least 95% by weight of the amount of the sweetening derivative present in the dough prior to baking. 34. A process as claimed in claim 23 wherein substantially all of the sweetening derivative present in the dough prior to baking is present in the baked dry extruded comestible. 35. A process as claimed in'claim 30 wherein said baking of the aough at the exit end of the extruder is at a temperature of from about 2100F to about 4000F for a residence time of less than or equal to about 4.0 minutes. 36. A process as claimed in claim 23 wherein the dough is baked, in the extruder at the exit end of the extruder and the residence time for baking of the dough at the exit end of the extruder is from about 0.2 minutes to about 4.0 minutes.

Inventors: DEMASO, PATRICIA, ROSS, ROBERT EDGAR, SPOTTS, JR., CLYDE EMERSON, STRAKA, ROBERT
Applicants: NABISCO BRANDS INC.
Application year: 1983
Main classification: A23L1
IPC codes: A23L1, A21D2