SHELF-STABLE PASTRY SHELL AND PROCESS

Abstract: A fully-baked, shelf-stable pastry shell having a moisture content of less than about 4%, and comprising on a dry weight basis: from about 50 to about 85% flour; from about 10 to about 45% fat, containing antioxidant in an amount effective to maintain product taste for at least six months of storage; and glycerine in an amount, up to about 5%, which is effective to maintain a resilient, flaky texture for at least six months storage.

Description: Shelf-stable pastry shell and process The present invention relates to fully-baked, shelf-stable pastry shells and to processes for preparing such pastry shells. Desserts and main dishes prepared with the delicate, flaky texture of pastry shells have universal appeal. Unfortunately, the preparation of pastry shells is a time consuming task which requires considerable skill. Prior art workers have endeavored to make the enjoyment of foods containing pastry shells more convenient by simplifying preparation in a number of ways. However, there remains a need for increased convenience. According to one early attempt, Bemis in U.S. Patent 2111021 described a process and an apparatus for preparing fully-baked pie crusts. According to his procedure, upper and lower crust portions are separately formed between mated baking molds. However, because Bemis does not describe any special formulation and does not make any special provision for maintaining taste, texture or structural integrity during shipping, handling and extended periods of storage, the product would be too delicate to stand normal shipping and handling and would lose its freshbaked flavor and fine texture over extended periods of storage. According to another prior art attempt in preparing food products with pastry shells, Kooistra discloses in U.S. Patent 3 294 547 that a low-moisture-content dough containing essentially from about 1% to about 15% by weight glycerine, from about 10% to about 25% by weight water, about 40% to about 55% by weight flour, and about 20% to about 35% by weight shortening, with the glycerine to water ratio being from about 1:9 to about 3:2, provides a dough having good shelf stability prior to use and good handling qualities during preparation. Similarly, Jaeger discloses in U.S. Patent 2 611 704 a dry mix containing glycerine for preparing a pie crust. The glycerine is said to maintain product moisture after baking. These compositions, however, are not intended for preparing fully-baked pie crusts for shipment, and still require considerable work for their preparation. According to another prior art approach, Ketch et al in U.S. Patent 3 492 127 discloses a non-refrigerated, ready-to-bake pastry product. To achieve the ability to maintain an unbaked crust dough in contact with a normally liquid filling material, Ketch et al reduces the moisture of the filling and dough portions to an equilibrium level of less than 15% before packaging. In addition, the unbaked crust dough contains glycerine or other polyhydric alcohol to replace part of the moisture, and employs a compound capable of reducing the disulphide linkages of the gluten. One disadvantage of products of this type, is that they are either dry to the taste upon eating or require rehydration prior to consumption. According to a more recent disclosure, Munter et al in U.S. Patent 4 265 919 describe yet another procedure for producing food products containing pastry shell. A frozen, pre-prepared shell is packaged along with a food material containing a liquid component also in the frozen condition. The shell is positioned over a centrally-depressed receptacle containing the normally-liquid material by means of an outwardly and downwardly extending rim around the receptacle. To prepare the product for consumption, the combined package is heated to liquify the filling material, and the package is then inverted to permit the liquid ingredients to fill the pastry shell for final baking. While products of this type may provide a degree of convenience, they also add a degree of inconvenience by requiring cooking and the use of the particular filling with which it is packaged. There remains a present need for a pastry shell product which provides the consumer with increased convenience but yet is of high quality and is capable of retaining that quality in terms of taste, texture, and structural integrity under the normal conditions of shipping and handling, and for normal periods of storage. There also remains a need for a process capable of producing such a product. It is an aim of at least the preferred embodiments of the invention: (a) to provide a fully-baked, shelf-stable pastry shell having adequate strength to withstand ordinary commercial distribution. (b) to provide a fully-baked, pastry shell which maintains its taste and texture for commercially-reasonable periods of shelf life (c) to provide a fully baked, shelf-stable pastry shell having structural strength to endure the normal conditions of shipping and handling, and being properly formulated to maintain its flavor and texture during a reasonable shelf life. (d) to provide a fully-baked pastry shell which is shelf-stable, structurally strong and has the advantage that it can be used as is or in recipes which require baking. (e) to provide a process capable of preparing a fully-baked, shelf-stable pastry shell having these desirable attributes. In its broad aspects, the pastry shell of the invention is shelfstable and is fully-baked to a moisture content of less than about 4%, and comprises, on a dry weight basis: from about 50 to about 85% flour; from about 10 to about 45% fat, containing antioxidant in an amount effective to maintain product taste for at least six months of storage; and glycerine in an amount, up to about 5%, which is effective to maintain a resilient, flaky texture for at least six months of storage. The process, in its broad aspects, comprises: preparing a dough by mixing from about 5 to about 20% water and from about 1 to about 5% glycerine with, on an as is weight basis, from about 45 to about 80% flour and from about 10 to about 40% fat, the fat containing antioxidant in an amount effective to maintain product taste for at least six months of storage; forming the dough into a sheet; positioning a continuous dough sheet within a baking pan, between the pan and a complementary form having a plurality of docking holes therein; and baking the shell. Preferred embodiments of the invention will now be described. Products of the invention are characterized by, in addition to their increased convenience, their practical adaptability to commercial grocery product distribution in terms of strength, physical integrity, flavor retention, and texture retention. To provide a degree of objectivity in defining these terms, storage tests to determine retention of the various properties over periods of time will be determined after storage for the indicated times at a temperature of 750F. The products of this invention will retain each of the significant attributes for a period of at least six months. Preferably, the products will maintain the desirable attributes for at least nine months of storage. While the overall flavor of the product should be maintained, one critical aspect of flavor is the lack of rancidity, which is the oxidation of the oil or fat in the product manifesting itself in a fishy, paint-like or musty aroma, depending on the chemicals used in the oil. It is also necessary in defining the compositions of the invention at various stages of processing to identify the basis for determining the percentage figures. Unless otherwise indicated, all parts and percentages will be based on the weight of the component as a part of the total composition at that particular stage of processing, unless otherwise identified. At points within the disclosure, the composition will be defined in terms of percentages on an "as is" weight basis and at other points, the composition must necessarily be defined in terms of "dry solids content". By the term "as is", it is meant that the normal commercial grade of ingredient is employed along with all volatile and non-volatile materials normally present. On the other hand, the term "dry weight" is meant to define the weight of the component dnly in terms of a totally dry product having all non-chemically combined water and other volatile materials removed. For example, soft winter wheat flour will typically contain from about 10 to about 14% moisture, and this moisture content will be included in the statement of the "as is" weight; however, the weight of the same flour component on a "dry weight" basis will be reduced from the "as is" weight due to the elimination of the moisture. The flour component employed according to the present invention can be derived from any suitable farinaceous source including wheat, oat, and rye, as well as other sources which are commercially available and typically employed for pastry shells. The selection of a particular type of flour will have an effect upon the ultimate product characteristics; however, the use of any particular source is not believed critical for purposes of processing or achieving the advantages of the invention. Thus, while it is preferred to employ a flour milled from soft, white winter wheat, which typically has a protein content of about 7.5 to about 8.5% and a moisture content of up to about 14%, flours from hard wheat containing protein contents substantially higher than this can be employed as the sole flour component or can be employed along with other flours having lower protein contents or even starches to achieve the textural attributes which may be desired for a particular product application. Most typically, the soft, white winter wheat will be a patent grade flour which is unbleached, unenriched and nonbrominated. Preferably, it will exhibit a viscosity (AACC Method 56-8) of 30 to 400 MacMichael, and a Hagberg falling number (AACC Method 56-81B) of at least 335. Similarly, the fat employed in preparing the dough can be selected from a wide variety of commercially available triglyceride materials. The fat can be selected from either the liquid or plastic-type shortenings derived from vegetable oils such as soybean or cottonseed oil and from animal fats such as lard. Examples of suitable shortenings are disclosed in U.S. Patent 2611704, U.S. Patent 2815286, U.S. Patent 2442537 and U.S. Patent 2801177. One particularly preferred, speciallyformulated fat will comprise partially hydrogenated soybean oil containing minor amounts of an emulsifier such as glyceryl monooleate and an antioxidant combination comprising buylated hydroxyanisole (B HA), tertiarybutylhydroquinone (TBHQ) and citric acid. The antioxidant system is composed of 28% butylated hydroxyanisole, 12% tertiary butylhydroquinione, 6% citric acid, 20% glyceryl monooleate and 34% propylene glycol. This blend is used at 0.05% of the weight of the fat. One especially preferred partially hydrogenated soybean oil will have a Wiley melting point of from about 950 to about 990F, a maximum iodine value of about 76, and a solid fat index at 500F of from 34 to 43 and at 0 92 F of from 3 to 8. Other hydrogenated and non-hydrogenated fats can of course be employed; however, it is preferred to employ those which are partially hydrogenated to achieve a Wiley melting point of at least about 900F and an iodine value of no higher than about 90. Liquid oils and those which are not hydrogenated to the preferred degree, will be more difficult to stabilize in terms of flavor over extended periods of storage. The total composition is formulated to provide a dough having typically good working capabilities; formed into a sheet; positioned as a continuous sheet, without docking, within a baking pan and between the pan and a complementary form having a plurality of docking holes therein for baking. As will be apparent later, baking the sheet without docking it is important to achieving the greatest strength in the final pastry shell. In preparing the dough, the fat will preferably be creamed, such as by mixing under conditions effective to assure that all lumps are broken up. Acccording to one preferred embodiment, the fat is creamed in an Artofex mixer for about two minutes at a temperature in the range of from about 700 to about 75 0F. After creaming, the flour component will be added to the fat and mixed for a period of time sufficient to provide a uniform blend, but being careful to avoid over mixing. According to one preferred procedure, the flour is added at a temperature of within the range of from about 600 to 650F and blended with the fat for about six minutes. After the admixture of the fat and flour has been prepared, itis then admixed with an aqueous solution containing glycerine, water, and any other water soluble or dispersable components of the dough. In addition to the glycerine and water, the composition will preferably contain from about 0.5% to about 2% salt and effective amounts of coloring and flavoring for the desired taste and appearance of the product. The dough at this stage in preparation will comprise from about 5 to 25% water and from about 1% to about 5% flour and from about 10 to about 40% fat. The fat will contain antioxidant in an amount effective to maintain product taste for a period of at least six months of storage at a temperature of 750F. And, the amount of glycerine will be selected to be effective to provide and maintain a flaky, resilient texture for a period of at least six months of storage at 750F. Preferably, the antioxidant and the glycerine levels will be adequate to provide retention of the indicated properties for at least nine months of storage at the indicated conditions. More preferred final dough compositions will contain from about 10 to about 15% water and from about 2 to about 3% glycerine with, on an as is weight basis, from about 55 to about 65% flour and from about 20 to about 30% fat. Also preferably, the composition will contain from about 0.5 to about 2.0% sodium chloride. If desired, sugar, flavors, color, and the like can also be employed. The combined mixture of dough ingredients is blended under conditions effective to provide the consistency typically desired for shaping and forming conventional pastry doughs. Typically, the complete dough admixture will be blended for about three minutes in a suitable mixer, such as an Artofex double arm mixer having a revolving mixing bowl. On completion of the dough preparation, the dough is fed to suitable crust forming equipment wherein it is divided into suitably sized portions and then sheeted to the size required. Typical of the equipment that can be employed is the Colborne crust forming equipment which typically shapes the dough into rectangular blocks of desired weight and then feeds the individual blocks into a system of cross-sheeting rolls to form individual dough sheets of suitable size.and having substantially continuous surfaces. Equipment of this type is typically capable of automatically depositing continuous dough sheets of this type into suitable baking pans. The baking pans can be of metal foil, such as aluminum foil, or they can be of ovenable paper or plastic materials. The top edge of the dough sheets can be crimped and fluted as desired. It is important to provide the dough sheets as continuous sheets in the sense that they are undocked and otherwise free of surface imperfections. While docking is conventionally thought to be necessary to provide areas for escape of water vapor generated during baking, it has been determined according to the invention that the perforations resulting from the docking create structural weaknesses within the shell which will cause ultimate failure during shipping and handling. Thus, according to the present invention, it is important to obtain a continuous dough sheet through forming and baking. By "continuous sheet" it is meant that the surface is not docked, such as by perforating along the sides or the bottom as is conventional in the art, and the surface has no significant cracks or cuts. After placing the continuous dough sheet within a pan or other suitable device for baking, the dough sheet is overlayed with a complementary form having a plurality of docking holes therein. The complementary form will be of sufficient weight to maintain the sheet in substantially close conformity with the sides of the pan during baking and prevent significant shrinkage. Additionally, the form will have a sufficient nurnber of suitably-sized docking holes to permit the release of steam during baking. Typically the form will be constructed of cold rolled steel coated with electro-deposited, remelted pure tin and then over coated with Teflon polytetrafluoroethylene, and will have circularshaped 3/32 inch holes spaced at intervals of approximately 1 inch about the bottom and the side surface. After suitably positioning the continuous dough sheet within a baking pan, between the pan and a complementary form having a plurality of docking holes therein, the sheet is then baked to a moisture content of less than about 4%. Typically, baking is accomplished on a continuous plate oven or other suitable baking oven to a moisture content of from 1.5 to about 3.5%. The temperature will be selected, based upon the formulation of the dough, on the details of construction of the pan and the complementary form, and the particular geometry of the oven to provide complete baking within a practical period of time. Typical baking temperatures will be within the range of from about 4000 to about 4400F. If desired, heat can be supplied by gas jet burners located over the top of the product as well as from the bottom. Typical baking times under these conditions employing preferred formulations will be on the order of about 14 to about 18 minutes. After baking, the product is discharged from the oven and is preferably cooled to a temperature adequate for packaging. It is preferred, to employ pans constructed of crimped aluminum sheet having a thickness of about 0.0045 inch which are maintained with the product during distribution. The complementary forms are removed, preferably prior to cooling the product. These forms are themselves cooled and recycled for further baking operations. Baking reduces the moisture content of the product to less than about 4%, and preferably to within the range of from about 1.5 to about 3.5%, most preferably about 2.0%. Thus, the composition of the final product on a dry weight basis will be from about 50 to about 85% flour, from about 10 to about 45% fat, and glycerine in an amount up to about 5%. Preferably, the pastry shell will comprise on this basis from about 60 to 75% flour and from about 20 to 40% fat. Also according to the preferred embodiment, the glycerine will be present at a level of about 2 to about 3% and, the ratio of the combined weight of fat and glycerine to the flour component will be 0.4 - 0.5:1. After cooling to a suitable temperature, on the order of 1000F or less, the baked pastry shells are packaged in a mahner capable of supporting the shells during transit so that the advantages achieved acccording to the present invention by providing a structurally strong, resilient, and yet flaky product are realized to their fullest extent. One preferred form of packaging comprises individual paperboard cartons surrounding individual pastry shells held within their aluminum baking pans, with a plurality of these cartons being stacked one upon the other, encased within a liner comprising polyethylene or other high polymer film material and placed with a corrugated shipping carton with several layers of a low density crimped paper cushioning layer positioned between the liner and the carton. Pastry shells packaged in this manner show extremely good tolerance to the normal abuses to which they are subjected in shipping and handling. The fully-baked pastry shell can be employed for the preparation of either hot or cold main dishes or desserts. These products can be prepared by adding either hot or cold filling materials containing sauces, puddings, fruits, vegetables, meats and the like for either eating as is or after cooking. It is an advantage of the present invention that the prebaked pastry shell can accommodate both uncooked cold fillings as well as fillings which require full cooking for usual periods of time after placement in the shells. The following example is presented for the purpose of further illustrating and explaining the present invention and is not to be taken as limiting in any regard. EXAMPLE A pastry crust according to the invention is prepared from the following ingredients: Ingredients Parts Soft White Winter Wheat Flour 62.8 Partially hydrogenated soybean oil, containing glyceryl monooleate emulsifier and 0.5% of an antioxidant composition comprising BHA, TBHQ and citric acid (Iodine Value = 76) 20.9 Water 12.43 Glycerine, USP 96% 2.63 Sodium Chloride 1.23 Annatto Color .01 After weighing out the ingredients, the shortening is creamed at about 700 - 750F in an Artofex mixer for about two minutes. The flour, at 600 - 65 0F, is then added and blended with the fat for about six minutes, taking precaution to avoid over-mixing. In a separate vessel, water at 400F, is combined with the salt, annatto coloring and glycerol.. The blend of flour and fat is then mixed with the resulting aqueous solution prepared above and mixed for three minutes on the Artofex until the dough is uniform and wetted. After mixing, the dough is processed on Colborne semiautomatic pie production equipment which processes the dough at a temperature of about 600 to about 65 0F. Individual balls of dough weighing from 8 to 9 ounces each are delivered to crust rollers where they are cross-rolled to form continuous individual dough sheets. The individual dough sheets are then deposited over individual moving aluminum pie pans. Each pan in this example is made from aluminum foil, having a thickness of 0.0045 inch, by crimping the side portions to form a pan having an 8 and 5/8 inch top inside diameter and a depth of 1 and 3/8 inches. The shell is then formed within the pan by means of rollers and the top outer crust edge is trimmed and fluted. The inner surface of the shell is then lightly dusted with flour to prevent sticking. A form having a shape complementary to that of the pan is then placed on top of the formed dough sheet. The form has a plurality of 3/32 inch diameter round docking holes with spacing of about 1 inch positioned in the side and bottom walls of the form to permit escape of water vapor during baking. The shells are then baked to a moisture content of about 2% to 3% at 0 440 F for about 16 minutes. The above description is for the purpose of teaching the person skilled in the art how to make and use the invention. The description is not intended to teach each and every modification and variation of the invention which will become apparent upon reading the description. However, it is intended that such modifications and variations be included within the scope of the invention.

Claims: CLAIMS 1. A fully-baked, shelf-stable pastry shell having a moisture content of less than about 4%, and comprising on a dry weight basis: from about 50 to about 85% flour; from about 10 to about 45% fat, containing antioxidant in an amount effective to maintain product taste for at least six months of storage; and glycerine in an amount, up to about 5%, which is effective to maintain a resilient, flaky texture for at least six months storage. 2. A pastry shell according to claim 1 which comprises an undocked, continuous shell. 3. A pastry shell according to claim 1 or 2 which comprises from about 60 to about 75% flour and from about 20 to about 40% fat. 4. A pastry shell according to claim 1, 2 or 3 which further comprises from about 0.5 to about 2.0% salt. 5. A pastry shell according to any preceding claim wherein the flour is soft, white winter wheat flour. 6. A pastry shell according to any preceding claim wherein the fat comprises a partially hydrogenated triglyceride having a Wiley melting point of about 900F. 7. A pastry shell according to any preceding claim wherein the antioxidant comprises a combination of butylated hydroxyanisole, tertiary-butylhydroquinone and citric acid in an amount of about 0.05%, based upon the weight of the fat. 8. A pastry shell according to any preceding claim wherein the glycerine content is from about 2 to about 3%. 9. A pastry shell according to claim 8 wherein the flour is present in an amount from about 60 to about 75%, and the fat is present in an amount from about 25 to about 35%. 10. A pastry shell according to claim 9 wherein the ratio of fat and glycerine: flour is in the range about 0.4 - 0.5:1. 11. A process for preparing a fully-baked shelf-stable pastry shell having a moisture content of less than about 4%, which comprises: preparing a dough by admixing from about 5 to 20% water and from about 1 to about 5% glycerine with, on an as is basis, from about 45 to about 80% flour and from about 10 to about 40% fat, the fat containing antioxidant in an amount effective to maintain product taste for a period of at least six months of storage; forming the dough into a sheet; positioning a continuous dough sheet within a baking pan, between the pan and a complementary form having a plurality of docking holes therein; and baking the dough to form a pastry shell. 12. A process according to claim 1 wherein the fat is creamed prior to adding the flour thereto, and the flour and fat are admixed prior to adding a solution of the glycerol and water. 13. A process according to claim 12 wherein the amount of water is from about 10 to about 15%, the amount of flour is from about 55 to about 65%, and the amount of fat is from about 20 to about 30%, all percentages based upon the weight of the total composition. 14. A process according to claim 13 wherein the ratio of fat plus glycerol to water is within the range about 0.4 - 0.5:1. 15. A process according to any one of claims 11 - 14 wherein the fat comprises a partially hydrogenated triglyceride having a Wiley melting point of above about 900F. 16. A process according to any one of claims 11 - 15 wherein the antioxidant comprises a combination of butylated hydroxyanisole, tertiary-butylhydroquinone and citric acid in an amount of about 0.05% based on the weight of the fat.

Inventors: HNAT, DIANE L., WARREN, ALISON B.
Applicants: NABISCO BRANDS INC.
Application year: 1983
Main classification: A21D2
IPC codes: A21D2