GB2091532A - Batter-coated foods - Google Patents

Abstract

Batter-coated food products are made by mechanically aerating a liquid batter mixture to lower its specific gravity, coating the surface of a food product with the aerated batter mixture, and further processing the coated product, such as by frying, in order to set the batter coating thereon. Additionally, by the incorporation of shortening in various forms to the liquid batter mixture prior to mechanical aeration, a variety of surface textures in the final product can be achieved. The present invention is particularly useful in connection with retaining crispness in a batter-coated food product which is partially fried and intended to be frozen and subsequently baked to completion.

Description

SPECIFICATION Improvements in batter-coated food products Due to the various problems associated with the preparation of deep fat fried foods, a need has arisen in the art to provide food products having the appearance and texture of deep fat fried foods while preparing such foods by techniques other than deep fat frying, such as baking and the like.

Since baking does not typically involve heat transfer on the order of that achieved during deep fat frying, sufficient moisture release during the cooking step to impart the same degree of product acceptability to the final product as is achievable during deep fat frying is prevented. Various coatings have been developed in an effort to provide baked products which nevertheless would simulate the deep fat fried products in texture and appearance. However, such products typically will not exhibit the same degree of product acceptability as do batter-coated products which are fried to completion.

The lack of product acceptability in products of the oven-ready type, i.e. partially fried, frozen and subsequently baked, is a result of the fact that the partial frying step does not include a sufficient rise in temperature to provide for adequate steam release and moisture escape. When the partially fried product is eventually baked to complete cooking, it is not supplied with sufficient heat transfer to result in the type of moisture release necessary to provide the desired degree of product acceptability, e.g., crispness.

As noted, in order to overcome certain of the foregoing drawbacks, attempts have been made to develop coating compositions which will provide the texture and appearance of deep-fried products in products of the oven-ready type. For example, U.S. Patent No. 3,843,827 discloses a process for simulating the texture and appearance of deep fat frying in foodstuffs without the necessity of deep fat frying itself. Specifically, the food product to be baked is first coated with a batter containing specific ingredients, particularly wheat flour. The batter-coated foodstuff is then coated with a dry mixture which comprises cereal fines, starch, flour, and fat, and subsequently baked until done. As disclosed, the result is a foodstuff having the texture and appearance of a foodstuff which has been batter-coated and then deep fat fried.

Similarly, in U.S. Patent No. 3,852,501, a process is disclosed which comprises coating baked foodstuffs with a powdered coating composition which includes farinaceous materials, edible shortening, modified starch and a corn starch hydrolyzate. Again, as disclosed, the resulting product when baked exhibits the appearance, texture, and taste of a deep fat fried product.

Finally, in U.S. Patent No. 3,586,512, there is disclosed a coating composition comprising a water-soluble food dye, edible fat and farinaceous material. Through the reaction of the baking heat and the concomitant moisture vapor from the food, the composition in question is said to develop into an appealing coating having the appearance, odor, texture and color equivalent of ordinary coatings applied to foods that have been deep fat fried. So far as known, however, none of these foregoing techniques has resulted in a product having product acceptability on the order of that achieved during deep-fat frying.

Still another problem which exists in the art regarding batter-coated food products has been the inability to develop techniques for manipulating the crust appearance in the coated food products in order to achieve varying texture effects. Other than the techniques disclosed in the foregoing patents, which are generally concerned with achieving the texture of a deep fried product in a product which is baked, the manipulation of crust appearance in batter-coated products has been essentially a function of external stimuli, such as the design of the receiving conveyor upon which the product is fried. Still further, the apparatus as described in U.S. Patent No.

3,450,026 suggests how one can retain a smooth coating on a batter-coated food product, such smooth coating normally being considered desirable.

It is also known that the puffiness of the coating in, for example, tempura-style products, can be adjusted through the use of chemical leavening agents such as baking powder. As the amount of chemical leavening is increased, the product exhibits increased fat absorption and tends to create a very smooth, even texture around the entire product's surface. it is believed that the smooth surface is the result of the fact that a volume containing envelope will strive to concentrate as much volume with as little surface area as possible. Where one desires to impart ridges to the product surface as is known in the art, the ridges which are formed by the design of the receiving conveyor produce a ridge only on the bottom receiving portion of the food product.This ridge becomes a crisp portion in the final fried product, but if the coating has greater than about 0.5 percent baking powder, the leavening action is such that it causes expansion of the crust with a corresponding loss of the receiving conveyor marks. The placement of these products in an oven results in intimate contact between the product and the baking pan which tends to exaggerate the oily and soggy appearance of the bottom of the product, which is typical for products of this type. The top portion of the baked product, likewise, has a glossy, oily appearance.

The soggy and oily appearance referred to is a common disadvantage in batter-coated food products of the oven-ready type and typically results from the release of a significant quantity of shortening from the product's coating during the final baking step. The released shortening derives from the shortening absorbed during the initial prefrying step and that originally present in the batter formulation itself. Apart from the loss of aesthetic appeal that results from the oily and soggy character of the products thus produced, the release of oil also presents a potential safety hazard as a result of handling a hot oil containing pan out of the oven.

Finally, a typical batter-coated products, it is necessary to have a batter pickup of less than fifty percent in order to avoid a decrease in product acceptability. Increased batter pickup, however, decreases the ultimate cost of the product since it permits the product weight to be determined in greater degree by the generally less expensive batter coating, rather than the more expensive food substrate. It would therefore be desirable to have a process which would permit increased batter pickup without a loss in product acceptability in the final cooked product.

In accordance with the present invention, there is provided a method for improving batter-coated food products. Generally, the method comprises mechanically aerating a liquid batter mixture in order to lower its specific gravity, coating the surface of a food product with the aerated batter mixture and then subjecting the coated product to further processing in order to set the batter coating thereon. In a preferred embodiment of the present invention, oven-ready type products are produced in which the batter coating is set on the surface of the food product by partial frying, followed by freezing and subsequent baking to cook the product to completion. Alternatively, the batter coating can be set by baking, freezing or the application of a breader to the batter-coated product. The breader can be, for example, socalled Japanese-style bread crumbs as described in U.S.Patent No. 4,068,009. In the case of freezing to set the coating, preferably such freezing will be carried out under cryogenic conditions to maintain the stability of the foam structure in the batter.

The present invention is based upon the discovery that increased product acceptability in batter-coated food products is obtained by mechanical aeration of the batter, during which the specific gravity of the batter is lowered from above about 1.1 to below 1.1. Preferably, the specific gravity of the liquid batter mixture will be lowered to from about 1.0 to 0.5, and most preferably to from about 0.9 to 0.7. While not wishing to be bound by any particular theory, it is believed that mechanical aeration results in the formation of air bubbles or channels which permit the efficient escape of steam and moisture during the partial frying and ultimate baking steps, roughly equivalent to that which is achieved under typical deep fat frying conditions where the temperature and pressure conditions of the frying normally create the air passages which permit such release.Thus, in accordance with the present invention, product acceptability on the magnitude of that achieved by deep-fat frying can be obtained in oven-baked products while avoiding the drawbacks associated therewith.

In another aspect of the present invention, various surface textures of the final product are achieved by incorporating shortening in various forms into the batter mixture prior to mechanical aeration. More particularly, it has been found that when shortening in the form of discrete fat particles is added to the batter mixture prior to mechanical aeration, surface textures of either a I bumpy or laminated nature can be achieved. For example, where the discrete fat particles are in the form of beads, a bumpy or "egg roll" texture is achieved, and where the discrete fat particles are in powder form, a laminated or flaky texture results.

In the event a smooth surface is desired, such as achieved in a typical Tempura batter product, the shortening should be either plastic or liquid in form. Combinations of various forms of shortening result in still further variations of surface texture, limited only by the particular combination of ingredients used.

Again, while not wishing to be bound by any particular theory, it is believed that the varying surface textures are the result of interaction between the fat particles and the air bubbles which are formed by aeration. In this regard, it is critical to obtaining crispness retention and the varying surface textures in accordance with the present invention, that the shortening be added to the batter mixture prior to aeration. Any attempt to add the shortening to the batter subsequent to aeration has been found to destroy the foam structure achieved by the aeration and to minimize the effect of either the presence of foam or shortening. However, the shortening may be incorporated into the batter mixture either before or after the batter is in liquid form.Specifically, it may be added to a dry mix to which a liquid, such as water, is then added to form the liquid batter mixture, or added directly to the liquid mixture after preparation.

It should be noted that mechanical aeration is a known technique which is used in the baking industry to impart smoothness and texture to cake batters which cannot be achieved through the use of chemical leavening systems exclusively.

Specifically, mechanical aeration results in a more uniform batter which in turn results in a lighter, more fluffy end product. Still further, in addition to the processing of traditional cake batters, mechanical aeration has been used in the production of low viscosity, aerated materials such as whipped toppings, pie fillings, and meringues.

However, so far as known, mechanical aeration has never been used in the production of fried or oven-baked batter-coated foods, nor has the relationship between specific gravity and product acceptability in batter-coated products been recognized, or the numerous advantages which have been found to flow therefrom.

Mechanical aeration of liquid batter mixtures in accordance with the present invention is preferably achieved through the use of conventional aerating equipment such as that disclosed in U.S. Patent Nos. 3,245,361 and 3,490,392. Such equipment is available, for example, from the Oakes Machine Corporation and from Goodway Industries, Inc. Specifically, such equipment will ordinarily include a holding tank which insures a constant supply of material to the metering or product pump on a continuous mixer in which the final aerated product is produced. The continuous mixer provides an intense mixing action which completely and uniformly blends all ingredients and provides for aeration. The gas used for aeration can be air, nitrogen, carbon dioxide, or any other non-toxic gas or mixture thereof.If desired, the equipment can also include a specific gravity control in the form of a densitometer which is connected to the mixer and constantly monitors the output of the mixture while adjusting the airflow accordingly.

Such devices have been found to be extremely accurate (+1 %) and permit the absolute control of final product specific gravity.

Mechanical aeration of a liquid batter mixture prior to applying the mixture to the surface of a foodstuff in accordance with the present invention will typically involve lowering the specific gravity of the batter to below about 1.1 and preferably to from about 0.9 to 0.7. It is critical to the present invention, however, that the specific gravity of the batter be lowered by mechanical aeration and not by some other means, such as chemical leavening systems, if the advantages of the present invention are to be achieved. In this regard, while chemical leavening systems have been used to lower the specific gravity of cake batter mixtures, such systems do not result in a stable enough foam formation and a sufficient lowering of specific gravity to achieve the advantages as heretofore described in batter-coated products.In this regard, chemical leavening systems have been incorporated in batter-coated products as a means of creating puffed coatings, as in Tempura-style products. However, the crust formation which results in the presence of chemical leavening systems alone appears to be directly opposite to that achieved when mechanical aeration in accordance with the present invention is utilized.

More particularly, it has been observed that the crust formation with chemical leavening means alone is in a direction away from the food substrate, while in the case of mechanical aeration or a combination of chemical leavening and mechanical aeration in accordance with the present invention, crust formation appears stationary or in a direction towards the food product. In this regard, it will be understood that conventional batter ingredients, such as chemical leavening, soya protein, eggs, and the like, may be incorporated into the batters which are to be mechanically aerated in accordance with the present invention without departing from the spirit and scope hereof.

In the context of the present invention, the "surface" of the food product to which the aerated batter coating is applied may comprise a bare and untreated food surface, such as an onion ring or fish portion; or if may comprise a food piece which has had a preduster or conventional batter and/or breader coating applied thereto. Further, the "surface" to which the aerated batter is applied need not be the entire surface of the product, but may comprise, for example, the bottom or top and sides only.

In connection with that aspect of the present invention whereby varying surface textures are achieved by incorporating various forms of shortening into the batter mixture prior to mechanical aeration, the particular shortening utilized can be in any number of forms which are readily available in the industry.Specific examples of shortening products in which the product comprises discrete fat particles include: Duratex, a product of Durkee Industrial Foods Group, a division of SCM Corp., which comprises partially hydrogenated cottonseed oil in the form of powder having an 80-120 mesh particle size; Kaorich, also a product of Durkee, which comprises partially hydrogenated cottonseed and/or soybean oil in bead form having a 30-60 mesh particle size; Beatreme 2784, a product of Beatrice Foods which comprises a spray-dried powdered emulsified shortening, corn syrup solids and milk product; KLX, a product of Durkee, which comprises partially hydrogenated cottonseed and/or soybean oil in the form of flakes;Durkee 17, which comprises partially hydrogenated soybean oil also in the form of flakes; and Duromel, a Durkee product comprising partially hydrogenated cottonseed and/or palm oil in flake form. Examples of plastic shortenings would include Diamond D-20 and Diamond D-80 which are both emulsified plastic shortenings manufactured by Durkee and comprise partially hydrogenated vegetable oil with mono- and di-glycerides added, and Diamond D-12 and Diamond D-10 which are examples of unemulsified plastic shortenings.

Where a smooth texture in the final product is desired, virtually any plastic or liquid shortening can be used. However, where a different texture such as a bumpy or laminated surface is desired, the shortening should be in the form of discrete particles such as beads or powder. In most cases, however, the shortening, regardless of form, should be present in the liquid batter in an amount of from about 0.5 to 20 percent, and preferably from about 1.0 to 5.0 percent by weight. Of course, still further variations on surface texture can be achieved by varying the level of shortening either within or without the specified ranges, depending on the particular effect which is sought to be achieved.

It has also been found that further variations in surface texture can be obtained by adjusting certain variables during the mechanical aeration, namely the back pressure and rotor speed of the mixer. Specifically, where shortening beads have been incorporated into the batter prior to aeration in order to impart a bumpy texture thereto, if the rotor speed is kept constant during aeration, the bumpy texture and porous qualities of the coating increase as the back pressure on the system is increased. If the back pressure is held constant, the surface texture becomes more apparent as rotor speed is increased, i.e., the greater the rotor speed, the more porous the coating. In this regard, the term "porous" is used to describe the presence of actual air cavities in the coating surface.At low rotor speeds, the surface exhibits few yet large air pockets, while at high rotor speeds, a larger quantity of smaller air pockets are visible. In all cases, however, the lower the specific gravity of the mixture, the more pronounced are the surface texture characteristics.

The following specific examples will serve to better illustrate the novel aspects of the present invention. Unless otherwise indicated, the technique utilized to prepare the products in question involves dry blending of a batter mix with discrete particles of shortening, preparing the liquid batter mixture using approximately eight parts by weight of water to 10 parts by weight of batter mix, and mixing for approximately one minute. Subsequently, the mixture is aerated using an Oakes Continuous Mixer. The batter is then applied to predusted products and the coated products prefried for 30 seconds at 3900 F. and subsequently frozen. Finally, the product is baked in an oven for 25 minutes at 4250F.Additionally, the product evaluations set forth in the examples have been, in most cases, limited to a particular improved product attribute for purposes of illustration only, it being understood that all the samples prepared in accordance with the present invention possessed other superior qualities than those explicitly stated.

EXAMPLE I Fish portions were prepared in accordance with the above technique utilizing two emulsified shortenings in plastic form (Diamond D-20 and Diamond D-80) at various percentages. The specific gravity of the liquid batter mixture prior to aeration was 1.15 and after mechanical aeration was found to be 0.825. The products produced under Oakes aerated conditions exhibited smooth, yet porous surfaces. It was established that the preferred level of shortening incorporation in the dry batter mix tested was approximately 3%. A batter pickup of 55% was recorded. After baking and storage at 700F. for over two hours, it was observed that the coated fish portion had retained excellent crispness. The crispiest products were those with batter pickups exceeding 50%.

EXAMPLE II Products were prepared incorporating Duromel, a flaked specialty shortening, into the batter mix prior to aeration. The batter specific gravities before and after mechanical aeration were 1.15 and 0.875 respectively, and a batter pickup of 50% was attained. The products which were obtained were characterized by a thick, creamy batter produced on a coated fish portion that was initially crisp and had good holding qualities.

Again, the higher the batter pickup, the crispier the final product.

EXAMPLE Ill Coated fish products were prepared incorporating 3% Duratex, a shortening in powdered form, into the liquid batter mixture. The initial specific gravity of the batter was 1.1 5 and after mechanical aeration it was recorded as 0.725. Batter pickup was 55%. Under Oakes aerated conditions, the final fish portion coating exhibited a layered or laminated character. The initial crispness and holding qualities were excellent.

EXAMPLE IV Fish portions were prepared incorporating 3% Kaorich shortening beads into the batter mixture.

The specific gravity of the mixture after mechanical aeration was 0.85, and a batter pickup of 50% observed. Products exhibiting exceptional crispness and holding quality, and a surprisingly dry interface between the food piece and coating were observed. The observation was further made that the underside of the fish portion was unprecedently firm and not soggy. The same products prepared with unaerated batter produced a relatively smooth fried surface as compared with the bumpy surface observed on the products utilizing the aerated batter.

EXAMPLE V Coated fish portions were prepared including 3% Kaorich shortening beads and 3% Beatreme 2784 powdered shortening in the dry batter mix prior to aeration. Initial specific gravity of the mixture was recorded as 1.125 and after mechanical aeration as 0.825 with a batter pickup of 45%. While a slightly different surface texture was achieved than with Example IV, equivalent results in terms of product acceptability were observed. Additionally, very few crumbs were observed in the fryer after product preparation.

EXAMPLE VI As a control, samples were prepared incorporating shortening into the batter mix and blending with a wire whip at low speed for two minutes. The mixture, in the absence of any mechanical aeration to lower its specific gravity of 1.15, was coated onto fish portions and a batter pickup of 45% observed. The products thus produced exhibited a smooth surface and lacked crispy eating qualities. Additionally, a significant number-of crumbs were observed in the fryer after product preparation.

EXAMPLE VII Natural onion rings and extruded vegetables were coated with mechanically aerated batter in accordance with the present invention. In all cases, the initial batter specific gravity was 1.15 and after mechanical aeration was found to be 0.825. The products produced exhibited extremely uniform coverage in addition to the other attributes of product acceptability discussed above. Additionally, it was found that the pseudoplastic nature of the batter allowed for a very wide range of percent batter pickup not normally obtainable under the prior art. Natural onion rings were found to have a 70% pickup, extruded vegetables a 72% pickup, and mushrooms a 60% batter pickup. These smaller products were baked for only twelve minutes and found to have exceptional eating characteristics.

EXAMPLE VIII The product of Example I was baked against a commercial sample of prior art batter-coated fish.

Immediately after baking, it was observed that the commercial product had about one-sixteenth inch of oil rendered out therefrom and that the rendered oil was shortly reabsorbed by the food product. The sample was observed as oily, not crisp, soggy, possessive of a gummy interface, and a significantly unequal top and bottom coating thickness. The product of Example I, on the other hand, was found to render no oil during the baking step and was observed to be very crisp, possess a dry interface, and have a nearly symmetrical coating thickness. The bottom of the food piece was observed as surprisingly crisp as well.

EXAMPLE IX Chicken parts were prepared with the batter of Example lil. An aerated batter pickup of 38% was obtained. Upon final baking the product was extremely crisp, possessed with good holding qualities, and otherwise exhibited all the attributes of the present invention as previously described.

With particular regard to those examples in which discrete fat particles in the form of beads are incorporated into the batter mixture prior to mechanical aeration, examination of the crust of the food products thus produced reveals that the entire surface thereof is covered with small bumps about 0.5 mm in diameter and 0.25 mm in height.

It is further observed that when such products are placed on the baking pan or sheet in the oven, the product is raised up from the baking pan as a result of the bumps. The bumpy crust allows for circulation of air under the food while it is baking.

By this simple mechanism, the bottom of the portion has its steam removed and is found to be particularly crisp. Still further, the bumpy crust provides certain advantages during freezing by limiting contact between adjacent products, thus resulting in better airflow which prevents sticking.

Still a further observation which has been made, is that the bumpy surface of the products produced in accordance with the present invention acts to diffuse the incident light, thereby giving the coating a non-glossy, less oily and greasy appearance. Still further, due to the more symmetrical coating which is achieved around all food products manufactured in accordance with the present invention, and the fact that both the bottom and top of the product will be comparably crisp, it is not necessary for a person to differentiate between top and bottom and therefore can place the food randomly on the baking pan, expecting the same quality no matter which way it is baked.

While the invention has been described with a certain degree of particularity, it will be understood that the description was by way of example only and that numerous variations and modifications, as may become apparent to those of ordinary skill in the art, can be made without departing from the spirit and scope of the invention as hereinafter claimed.

Claims (25)

1. A method for preparing improved battercoated food products, comprising the steps of mixing a dry food-coating batter mix with a liquid to prepare a liquid food-coating batter mixture, mechanically aerating said liquid food-coating batter mixture to lower its specific gravity, coating the surface of a food product with said aerated batter mixture, and subjecting the batter coated product to further processing to set the batter coating thereon.

2. A method according to Claim 1, wherein said further processing comprises partially frying said batter-coated product at a temperature and for a time sufficient to set the batter coating thereon, and further comprising the step of freezing said partially fried batter-coated product.

3. A method according to Claim 2, further comprising the step of baking said frozen battercoated product at a temperature and for a time sufficient to cook the product to completion.

4. A method according to Claim 1 , wherein said further processing comprises applying a breader to said batter-coated product.

5. A method according to Claim 1, wherein said further processing comprises freezing said battercoated product.

6. A method according to Claim 1 , wherein said further processing comprises frying said battercoated product at a temperature and for a time sufficient to set the batter coating thereon.

7. A method according to Claim 6, further comprising the step of baking the batter-coated and fried product at a temperature and for a time sufficient to cook the product to completion.

8. A method according to Claim 6, further comprising the step of continuing to fry said batter-coated and fried product at a temperature and for a time sufficient to cook said product to completion.

9. A method according to any one of the preceding claims, wherein said liquid batter mixture is mechanically aerated to lower its specific gravity below about 1.1.

10. A method according to Claim 9, wherein the specific gravity of said liquid batter mixture is lowered to from about 0.9 to 0.7.

11. A method according to any one of the preceding claims, further comprising the step of incorporating shortening into said liquid batter mixture prior to mechanical aeration of said mixture.

1 2. A method according to Claim 11, wherein said shortening is added to said liquid batter mixture in an amount from about 0.5 to 20 percent by weight of said mixture.

1 3. A method according to Claim 12, wherein said shortening is added to said liquid batter mixture in an amount of from about 1.0 to 5.0 percent by weight of said mixture.

14. A method according to Claim 11, 12 or 13, wherein said shortening is added in the form of discrete fat particles, in powder form, in the form of beads, in the form of flakes, in liquid form, or in plastic form.

15. An improved batter-coated food product, comprising a food product having a mechanically aerated liquid food-coating mixture coated and set on the surface thereof.

16. A food product according to Claim 1 5, wherein said batter has been set on the surface of said food product by either frying, freezing, or baking, or by applying a breader to said battercoated product.

17. A food product according to Claim 1 5 or 16, wherein the specific gravity of said batter mixture is below about 1.1.

18. A food product according to Claim 17, wherein the specific gravity of said batter mixture is from about 0.9 to 0.7.

19. A food product according to any of Claims 1 5 through 18, wherein said mechanically aerated batter mixture includes shortening, said shortening having been incorporated in said liquid batter mixture prior to its being mechanically aerated.

20. A food product according to Claim 19, wherein said shortening is present in an amount from about 1.0 to 20 percent by weight of said food product.

21. A food product according to Claim 20, wherein said shortening is present in an amount of from about 1.0 to 5.0 percent by weight of said food product.

22. A food product according to Claim 19, 20 or 21, wherein said shortening was added in the form of discrete fat particles, in powder form, in the form of beads, in the form of flakes, in liquid form, or in plastic form.

23. A food product according to any of Claims 1 5 through 19, wherein said aerated batter coating is present in an amount greater than 50% by weight of said food product.

24. A method for preparing improved batter coated food products substantially as described.

25. An improved batter-coated food product substantially as described.