The invention provides a fully assembled frozen food product comprising a bread portion having a top portion and a bottom portion and having a filling between, and co-extensive with, the top and bottom portions, wherein the fully assembled frozen food product can be heated in a microwave oven to provide a heated food product which is then ready to be eaten, wherein the bread portion of the heated food product is not dried out and wherein the filling in the heated food product has an essentially uniform temperature. Generally, the bread portion before microwave heating will have a water activity in the range about 0.9 to about 0.96 and will retain satisfactory texture and chewability characteristics after microwave heating. Generally, the filling after microwave heating will have an essentially uniform temperature of about 160 to about 195° F. (i.e., no cold or frozen spots therein) and good organoleptic properties.
Thus in preparing the fully assembled frozen food products of this invention it is important to insure that the filling is co-extensive with the top and bottom bread portions. Thus, the top and bottom surfaces of the filling should have approximately the same shape and surface area as the corresponding surfaces of the top and bottom bread portions so that sufficient overlapping of the filling and the top and bottom bread portions (see, e.g.,
The fully assembled frozen food product can be contained in a package that can also used to hold the fully assemble frozen food product during microwave heating so that the co-extensive nature of the food product can easily be maintained during microwave heating. Alternatively, instructions should be provided so that the consumer maintains the co-extensive nature of the food product during microwave heating. Of course, if the filling is co-extensive with the bread portions at the time of freezing, the frozen nature of the product will likely assist in maintaining the co-extensive relationship during distribution. The packaging is designed to assist in maintaining this co-extensive relationship during distribution.
Preferably, the fully assembled frozen food product is supplied with an appropriately sized and shaped susceptor or susceptors to assist in the microwave heating process. Various types and forms of susceptors as are known in the art can be provided for use in the present invention. For example, the susceptor may be a film having a layer of metal deposited thereon. In addition, the susceptor may have different thicknesses to assist in concentrating heat energy at select portions of the fully assembled frozen food product. The susceptor may be an integral part of the packaging of the fully assembled frozen food product or may be a separate component upon which the fully assembled frozen food product is placed before microwave heating.
The susceptor is preferably, though not necessarily, of a type that expands upon heating to better conform to the adjacent portion of a food product. One especially preferred expanding susceptor material is made and sold by Graphics Packaging, Inc., Marietta, Ga., under the product name QuiltWave™. In addition, the expanded susceptor can have multiple channels or groves formed therein that permit venting of moisture away from the surfaces of the food product adjacent thereto. Such venting can advantageously reduce the potential for moisture accumulation on those surfaces of the food product adjacent the susceptor. Other venting mechanisms may be used instead or in addition. For example, a corrugated susceptor material may also function to vent moisture during microwave heating.
Preferably, both a bottom susceptor and a top susceptor are used to effectively surround or enclose the fully assembled frozen food product. Especially preferred embodiments of such susceptors are shown U.S. patent application Ser. No. 11/284,801 (filed Nov. 22, 2005), which is hereby incorporated by reference in its entirety. Preferably, both the bottom and top susceptors are formed using the QuiltWave™ material and have appropriate venting mechanisms to allow moisture to escape.
Baking science involves a complicated process employing time, temperature and relative humidity to produce various bread products. The time, temperature and relative humidity parameters are generally different for bread, rolls, pizza crusts, pastry and cereal products, not only with regard to their appearance (crust color, size, etc.), but also with regard to the development, texture, and size. Some of the desirable changes caused by baking are protein denaturing, starch gelatinization, moisture migration and veracity (cell development or grain). Many factors may be involved in preparing a baked product which is appealing in the eyes of the ultimate consumer. A manufacturer must also consider items such as shelf life and how a consumer will actually use a product. Consequently, it is desirable to have some quantitative measure by which one can determine whether a production line product meets specification. One such measure is water activity.
Water activity is a measure of the percent of water remaining in a baked product after it has been baked. Cracker products typically have a water activity in the range of about 0.35 to 0.50. Common baked goods, for example, bread, dinner rolls and pizza crusts, typically have a water activity in the range of about 0.90 to 0.98. The fully baked or par-baked bread products of this invention preferably have water activities of about 0.9 to about 0.96, with a value of about 0.93 being particularly preferred. Such fully baked or par-baked bread products have satisfactory frozen storage characteristics as well as satisfactory texture and taste when heated in a microwave oven.
The water activity of the bread product is measured after it has come out of the oven and cooled to about 100° F. Moisture content of the baked bread product may be measured with an aw meter, or by weight difference between the bread product after cooling to about 100° F. and after further, more complete drying (i.e., using a desiccator or other suitable and reliable method). Generally, the moisture content of fully baked or par-baked bread product is about 30 to 38 percent, and preferably in the range of about 34 to about 38 percent.
Since yeast is included in the formulation of the bread dough, a fermentation step is included in the dough preparation. The fermentation step allows the yeast to produce carbon dioxide gas which stretches and mellows the gluten contained in the flour, and aids in producing good flavor and texture. Techniques such as the “sponge and dough” method (i.e., fermenting a portion of the dough and adding an aliquot of the fermented dough to bulk unfermented dough) or the “brew system” method (i.e., fermenting some yeast, flour, and the like in a liquid system and then adding as separate ingredient) could be used if desired. Punching down, if used, occurs after fermentation and proofing.
The bread products used in the present invention may be prepared using a dough containing a combination of gums (e.g., xanthan and guar with the xanthan at higher than conventional levels) and additional ingredients (e.g., methylcellulose and DATEM) in the dough formulation provides an improved bread product for use in this application. Although an enzyme as used in the dough formulations of U.S. Pat. Nos. 6,764,700 and 6,919,097 (both of which are incorporated by reference in their entireties) is not needed in the present application (and therefore is preferably not used), it can be included if desired. Thus, an especially preferred recipe (in baker's percentages) for the dough prepared according to a preferred embodiment of the invention is provided in the following table.
Moreover, the dough formulations of U.S. Pat. Nos. 6,764,700 and 6,919,097 could be used in the present invention if modified to include the combination of gums (e.g., xanthan and guar) and additional ingredients (e.g., methylcellulose and DATEM) as used in the present invention. In other embodiments, other ingredients may be substituted for those listed above. For example, calcium stearoyl lactylate might be used in place of, or with, the sodium stearoyl lactylate. The flour is preferably hard wheat bread flour made from hard spring or winter wheat. Suitable oils and/or fats include vegetable oils, shortening, hydrogenated fats or oil, and the like. Preferably the fat is a solid, hydrogenated or partially hydrogenated vegetable oil; for example, a hydrogenated or partially hydrogenated cottonseed, corn, soybean, sunflower, canola oil, or mixture thereof, and similar hydrogenated or partially hydrogenated vegetable oils and mixtures. The preferred vegetable oils are corn, canola, sunflower seed, cottonseed and soybean oils, or mixtures thereof, with soybean oil being the most preferred; fat substitutes such as Olestra™ and Benefat™ can also be used in combinations with such oils or fats. The oil may have a butter flavoring agent added by the producer. Alternatively, a butter flavoring agent or other flavoring agent may be added to the recipe in an amount known to those skilled in the art or in accordance with the flavor manufacturer's recommendations. Generally, the preferred sweetener is sucrose. Other types of sweeteners (e.g., natural, artificial, corn syrups, and the like); of course, if use, the levels of such other sweeteners should be adjusted to provide the desired level of sweetness and, if necessary (i.e., if corn syrup is used), the level of water may be adjusted to account for water added with the sweetener. Dry yeast may be substituted for the compressed yeast used in the above basic recipe. If dry yeast is used, the baker's percentage or weight is cut to account for the water content of the compressed yeast; likewise, the amount of water added may be increased to account for the water content of the compressed yeast. Therefore, if dry yeast is used in the above general recipe in place of compressed yeast, the amount (flour basis) of dry yeast will be in the range of about 0.3 to about 1.7 percent, preferably about 0.6 to about 1 percent.
The fully baked or par-baked bread is then generally sliced to form the top bread portion and the bottom bread portion of the sandwich. If the fully baked or par-baked bread is in the form of a bun or roll, it is sliced so that the two halves form the top (the so-called “crown”) and bottom (the so-called heel) bread portion. If the fully baked or par-baked bread is in the form of a loaf, slicing it will generally result in multiple slices (depending on the size of the loaf) which can be used to form more than one fully assembled sandwich. Generally, the fully baked or par-baked bread is sliced completely through to form separate top and bottom bread portions. If desired, however, the slicing may not be complete such that the top and bottom bread portions remain attached through a hinge so long as the filling can be placed between the top and bottom bread portions. For stromboli-type or calzone-type sandwiches, slicing is generally not necessary since the dough encloses the filling. Such sandwiches may be open at one or more ends (see
The filling is then placed on one of the top or bottom bread portions (preferably on the bottom bread portions) using any suitable automatic, semiautomatic, or manual technique. Suitable fillings include, for example, meats (e.g., chicken, turkey, beef, ham, and the like), cheeses, vegetables, tofu, soy, soy derivatives, and the like as well as combinations thereof. Such fillings may also include sauces, dressings, spreads, gravies, condiments, spices, flavorings, colorants, and the like as well as combinations thereof. Generally, such fillings have a relatively high moisture content (i.e., about 60-80 percent or higher). Preferably, meat and vegetables in the filling are in the form of lumps or diced shapes (generally less than about 2 inches in the longest dimension).
The meat may be in a shaved, sliced, shredded, chopped, or other convenient form. The type of meat that may be used is not particularly limited. The meat may be beef (e.g., roast beef, barbecued beef, steak, hamburger, etc.); poultry (e.g., chicken breast, barbecued chicken, turkey breast, turkey burger, chicken salad, etc.); pork (e.g., ham, barbecued pork, ham salad, etc.); fish (e.g., tuna, tuna salad, lox, etc.); egg products. The meat filling also may be processed meats like bacon, sausage, bologna, olive loaf, pepperoni, salami, corned beef, pastrami, liverwurst, and so forth. Combinations of such meat products may be used if desired. Soy or soy derivative products may be used as a protein source in combination with the meat filling, or alternatively in place thereof in the sandwich filling. The water content and water activity of the meat filling may vary greatly depending on the type of meat selected. For instance, leaner cuts of meat generally contain less water content than less lean cuts. For example, processed luncheon meats or deli style meats that may used in the sandwich constructions described in embodiments herein may comprise about 70 to about 80 percent moisture.
The type of cheese that may be used is not particularly limited. The cheese may be in form of shredded, sliced, shaved, flaked, powdered, crumbled, slabbed, creamed, and so forth; preferably, the cheese is in the form of cheese shreds The cheese type, for example, may be process cheese, cheddar cheese, Swiss cheese, American cheese, Provolone cheese, mozzarella cheese, Parmesan cheese, blue cheese, Monterey Jack cheese, Romano cheese, cream cheese, Havarti cheese, Gouda cheese, Muenster cheese, Asiago cheese, Gorgonzola cheese, and combinations thereof. The water content and water activity of the cheese may vary greatly depending on the type of cheese selected; preferably the cheese contains about 40 to about 45 percent moisture.
Vegetables suitable for use in the filling include, for example, onions, tomato, peppers, garlic, bean sprouts, cucumber, zucchini, potato, kale, basil, and the like as well as combinations thereof.
Both the bread portions and the filling can be seasoned, such as with salt, pepper, oregano, hot pepper flakes or spreads, onion powder, garlic powder, sesame seeds, poppy seeds, cinnamon, and the like as well as combinations thereof. Food additives, such as preservatives, flavorings, colors, emulsifiers, soy flour, and so forth, also can be included in or applied to the fillings.
All or some of the ingredients in fillings may be premixed if desired; alternatively, all of some of the ingredients may be individually placed on the appropriate bread portion. All or some of the ingredients in the filling may be frozen or thawed when placed on the appropriate bread portion. Indeed the entire filling may be prepared and then frozen into the appropriate size and shape (i.e., puck or other shape) to fit in the sandwich and then placed frozen in the sandwich. The bread may also be pre-frozen. Once the filling is placed on the appropriate bread portion the sandwich is assembled by appropriately placing the other bread portion with the covered bread portion. Generally, the assembled filled sandwich is frozen after being assembled. Conventional freezing techniques are used to freeze the assembled sandwich. Preferably, the sandwich is frozen within about 30 minutes after being assembled, and more preferably within about 2 to 5 minutes, after being assembled with a blast or nitrogen tunnel freezer. The assembled sandwich is packaged, preferably using modified atmosphere techniques, frozen (if not already frozen), and then stored under suitable conditions. Susceptors, if used, may be included in the same package as the assembled sandwich or may be separately contained in the kit.
As is well known in the art and discussed above, heating bread in a microwave oven for a relatively long period of time is very abusive in terms of the bread organoleptic properties. Thus, microwave heating of a fully-assembled conventionally-sized frozen sandwich for a time sufficient to raise the temperature of the center of the frozen filling to at least about 160° F. is a harsh and difficult environment. Microwave heating of similar types of products which (1) are smaller in size and/or weight, (2) are open faced such as pizza or open faced sandwiches, and/or (3) contain less bread, filling, and/or topping would not present as great a challenge. The bread formulations of the present invention are designed so as to provide good organoleptic properties even under such harsh and difficult microwaving environments. Thus, the use of bread formulations of the present invention to prepare bread products which do not present as great a challenge a fully-assembled conventionally-sized frozen sandwich would be expected to provide microwavable products having as good as, if not better, organoleptic properties as similar products prepared with conventional dough formulations, including conventional dough formulations used in microwavable products currently available in the marketplace. Although the present dough formulations are especially designed for use with the fully-assembled conventionally-sized frozen bread products, and especially with the fully-assembled conventionally-sized frozen sandwiches, of this invention, the present dough formulations can be used to advantage in other bread products, including those intended to be heated in microwave ovens.
The following examples are intended to illustrate the invention and not to limit it. Unless otherwise noted, all percentages, ratios, and the like are based on weight.
This example illustrates the preparation of several bread products. The resulting bread products were evaluated for their ability to withstand microwave heating. Two control bread products and one inventive bread product were prepared. The first control bread product was prepared from a conventional dough formulation. The second control bread product was prepared from a dough similar to the inventive dough formulation except that xanthan gum was omitted from the formulation. The formulations, expressed in Baker's percentages, for the three dough samples are provided below:
After mixing the dry ingredients in a Hobart mixer for about 30 seconds (low setting), the yeast, shortening, oil, flavorings, and water were added and mixing continued for about 2 minutes at a low setting followed by an additional 4 minutes at a higher setting. After holding the dough for about 5 minutes, it was divided into 110 g units and formed into oval shapes. The individual units were then proofed at about 105° F. for about 40-50 minutes at 80-85 percent relative humidity. Proofed units were then used as is (i.e., non-punched) or were punched. After baking in an impingement oven at 450° F. for 4.5 minutes, the fully baked or par-baked bread were cooled and sliced by hand using an electric knife to form top and lower bread portions. The top and lower bread portions were then combined (without filling as in the original unsliced form), frozen, and then packaged under modified atmosphere conditions.
For evaluations, the frozen assembled sandwiches (without any filling between the top and bottom bread portions) were placed on a raised tray without a susceptor and heated in a microwave oven at full power for 1 minute and 30 seconds. The heated bread products were then removed from the oven and held at ambient temperature for 5 or 15 minutes before quality evaluation by trained experts (for consistency, the same experts were used in all evaluations). The crown (i.e., top surface) and crumb (i.e., cut surface) of the top portion and the crumb (i.e., cut surface) and heel (i.e., bottom surface) of the bottom portion were examined for hardness. Hardness was measured on a 1-5 scale (1 for soft and 5 for “rock” hard); thus, for hardness, a lower score indicates a more desirable result. Two parameters were measured for each of the four surfaces: (1) the hardness of the hardest spot found; and (2) average or overall hardness based on coverage of hard spots and their hardness. The percentage of surface covered by hard spots (independent of the degree of hardness) was also estimated for each of the four surfaces. The results were summed over all surfaces and averaged. The following average results were obtained for non-punched and punched samples:
The overall quality of each bread sample was also evaluated 5 and 15 minutes after microwaving using a 1-5 scale with 1 the best and 5 the worst. The following results were obtained:
This example illustrates the preparation fully assembled frozen sandwiches using the three bread products (both punched and non-punched in bun form) described in Example 1. For evacuation, each fully assembled frozen sandwich was placed on a raised, vented tray without a susceptor and microwaved at full power from the frozen state until the center portion of the filling reached a minimum temperature of about 160° F.; typically the time required to reach this minimum temperature was about 3.5 minutes; the temperature range of the filling was about 160 to about 165° F. The quality of the bread was evaluated after microwave treatment using similar criteria as in Example 1 except that the crumb parameters were not obtained since there was filling contacting the crumb. The data was converted to a single average quality score on a 1-5 scale (1 being best with 5 being worst).
A filling comprising about 60 percent cubed chicken, about 15 percent diced vegetables, about 7 percent spinach, and about 18 percent shredded asiago and mozzarella cheese was prepared by mixing. The filling was shaped into a patty (about ⅝ inches thick) so as to be co-extensive with the bun and then frozen. The fully assembled sandwich was then formed by placing the frozen filling patty between the top and bottom bread portions and frozen at about 20° F. for about 24 hours. The fully assembled frozen sandwich products weighted about 8 ounces.
The following results for the overall quality of the bread portion of the microwave heated sandwiches (data at 5 and 15 minutes after microwaving combined) were obtained.
The inventive sandwich had good organoleptic properties and was clearly superior to Control 1 and better than Control 2 sandwiches. The inventive sandwich prepared with punched bread was somewhat better than the inventive sandwich prepared with non-punched bread.
This example provides a comparison of the inventive sandwich of Example 2 (using the punched bread in the form of a bun and the chicken/vegetable/cheese filling) with a commercially available frozen sandwich. The commercial sandwich (Stouffer's Corner Bistro® Philly-Style Steak and Cheese Panini) was assembled by placing the individual slices with filling together to form an assembled sandwich. Both the inventive assembled sandwich (about 8 ounces) and the assembled commercial sandwich (about 6 ounces) were heated separately from the frozen state in a microwave oven at full power for 3.5 minutes. The temperature of the filling reached a minimum of about 160° F. for both sandwiches.
The heated sandwiches were allowed to stand for about 5 minutes before evaluation. The bread portion of heated commercial sandwich had a chewy, but acceptable, crumb texture and an extremely chewy and unacceptable crust. The bread portion of the heated inventive sample had good overall texture and organoleptic properties with some, but acceptable, hardness at the ends. The heated inventive sample was of better overall quality.
This example provides a comparison of the inventive sandwich (using two slices of bread made from a loaf of the inventive formula and the chicken/vegetable/cheese filling of Example 2) with bread from a commercially available frozen sandwich (Stouffer's Corner Bistro® Panini) and the same chicken/vegetable/cheese filling of Example 2. The inventive dough composition was used to prepare a loaf (about 4 by about 4 inches and about 13 inches long) and then baked at about 400° F. for about 25-35 minutes. After cooling, the loaf was cut into slices about ½ inches thick. The chicken/vegetable/cheese filling of Example 2 was then formed into patty of about 26 square inches (and of a form co-extensive with the bread slices) and about ⅝ inches thick and then frozen. The frozen patty was placed between two slices of the bread and then frozen at about 20° F. for about 24 hours. The fully assembled frozen sandwich was about 7 ounces.
The fully assemble frozen sandwich was then heated in a microwave oven at full power for 3.5 minutes on a raised, vented cardboard platform (without a susceptor). The temperature of the filling in each sandwich reached a minimum of about 160° F. After standing for about 5 minutes, the top bread slice of the heated inventive sandwich had toasted, but not hard, texture (especially at the corner and crust areas) whereas the bottom slice was somewhat steamed and softer than the top slice. Overall, the heated sandwich had very good texture and organoleptic properties. The heated commercial sandwich, on the other hand, had a slightly chewy (but acceptable) crumb but a very chewy and leathery crust (and not acceptable).
The inventive fully assembled frozen sandwich of Example 4 was heated in a microwave oven at full power for 3.5 minutes using top and bottom susceptors as described in U.S. patent application Ser. No. 11/284,801 (filed Nov. 22, 2005). The temperature of the filling reached a minimum of 160° F. After standing for about 5 minutes, the top bread slice of the heated sandwich had a toasted, but not hard, texture (especially at the corners and crust portion) whereas the bottom slice was somewhat softer with toasted areas where it contacted the susceptor. Overall, the heated sandwich of this example had excellent texture and organoleptic properties. Indeed, the heated inventive sandwich of this example was better than the heated inventive sandwich of Example 4 due to the toasting and crisping of the bread on the bottom of the sandwich.