Hydrolyzed gluten-based coating composition for fried foods

Abstract

The present invention relates to fried foods, and in particular to the use of hydrolyzed gluten in coating compositions for fried foods.

Description

[Technical field]

[0001] The present invention relates to fried foods, and in particular to the use of hydrolyzed gluten in a coating composition for fried foods. [Background technology]

[0002] Frying is a cooking method in which food is immersed in hot edible oil. This is usually done using a deep fryer or pan, and industrially pressure or vacuum fryers may be used. Frying is classified as a dry cooking method because no water is used. Due to the high temperatures involved and the high thermal conductivity of the oil, the food is then quickly prepared.

[0003] Deep-fried food preparation methods often include a coating process for food products, which was first introduced commercially for seafood in the late 1930s. Today, many food products are coated, and commercial coating skins are formulated from a variety of flours, seasonings, batters, and breadings that enhance the appearance and texture of the food product while retaining flavor and moisture.

[0004] In fried food preparations, the coating process improves the visual appearance and identity of the food product, enhances palatability by adding flavor, modifies texture, mouthfeel or "chewiness", modifies nutritional value (addition of vitamins or calories), increases yield to increase product value, reduces product cost, allows for the use of off-cuts / waste, protects the product during freezing, or allows for more reconstitution methods.

[0005] Typically, the coating process for food products involves three types of batter skins arranged in three successive layers. Undercoating or glazing, which is a dry batter skin used to form an intermediate layer between the food product and the next batter layer. Undercoating or glazing by adhering to the food prepares the surface of the food for the application of the next layer. A batter, a moist batter skin, is applied over the undercooking layer to form a base for the third layer of breadcrumbs to adhere to. Breading (or breader), a dry (particulate) crust that is a generally cereal-based product and that is granulated after baking into fine, medium, or large crumbs. Breading typically contains ingredients ranging from flour to breadcrumbs and coarse corn flakes.

[0006] Shimo-mabushi or mabushi comprises a finely ground grain-based breading or dry batter mixture. It is usually applied to the food product as a first layer to prepare the surface of the food product for the application of the next layer. Shimo-mabushi may be a pre-made commodity or a product made for a specific product or process. They are usually flour-based but may contain additional agents to help the batter skin adhere to the ingredients. Shimo-mabushi and mabushi are always in dry powder form.

[0007] Flour-based coatings have been used for many years, but they have many drawbacks, one of which is that it is relatively difficult to keep the internal juices of hot fried foods moist under storage at high lamps or after reheating in an oven or microwave. The juices from the inside seep out and make the food tough.

[0008] After cooking, food products with flour-based coatings do not maintain their crispy texture for long. At room temperature, the surface moisture migrates from the coating layer, resulting in a soft texture. However, after cooking, even if the fried food is stored in a hot showcase, the food becomes hard and the outer texture becomes chewy. Thus, flour-based coatings are unable to maintain their texture after cooking.

[0009] Furthermore, flour-based coatings also have a weak adhesive function. To produce a good appearance of fried foods, good adhesion between the topping and the batter layer is important. Flour-based coatings do not allow good adhesion between these two layers. Furthermore, poor adhesion affects not only the appearance of the product but also its texture. Therefore, this parameter is considered as a critical parameter for fried foods.

[0010] Fried foods can be eaten immediately after frying, but they can also be stored under infrared lamp storage to keep them hot for over 4 hours. Such storage is very common in Asian countries in convenience stores and supermarkets. Unfortunately, soon after storage, fried foods lose their juices and crispy texture.

[0011] After frying, the fried foods can also be stored refrigerated, for example in a refrigerator, and reheated in a microwave oven or a conventional oven, in which case the fried foods lose a significant amount of juices that make them drier than they were freshly cooked.

[0012] Wheat gluten is used for its film-forming ability and is of interest in the food industry. In "Wheat Gluten Applications in Food Products" (Kalin & al., J. Am. Oil Chemists Soc., March 1979, V5-, p477-479) wheat gluten is described as "the unique film-forming properties of hydrated vital (active) wheat gluten". Vital wheat gluten is primarily used in baking, but is also used in breading and batters. Kalin et al. do not mention coating at all.

[0013] Wheat gluten is known as a colloidal form of edible coating, as disclosed in US Patent No. 6,174,559. This patent teaches the use of a colloidal solution of hydrolyzed gluten as an improved edible coating. In this document, hydrolyzed gluten is the only dry compound used (100% colloidal solution in dry matter). Furthermore, the use of hydrolyzed wheat gluten in frying processes and coatings is not disclosed.

[0014] In the field of fried foods, the Applicant has found an inventive solution involving the use of hydrolyzed gluten in the coating to avoid the drawbacks mentioned herein above.

[0015] The invention is described in the General Description section below. Summary of the Invention

[0016] The inventors have shown that the use of hydrolyzed wheat gluten in coatings allows the meat to retain its juicy taste even when stored in a hot showcase (infrared lamps) immediately after frying or after 4 hours. A clear difference with conventional products is shown in the following examples: fried foods obtained with coatings containing hydrolyzed wheat gluten retain moisture inside, maintain a crispy texture, and maintain better adhesion of the batter and breadcrumbs.

[0017] As shown in the examples below, a coating composition containing only hydrolyzed wheat gluten is not strong enough to retain the juices in the fried food. In the coating composition, the hydrolyzed wheat gluten should be greater than 1% and less than 65%.

[0018] A first embodiment is a coating composition for fried foods, comprising hydrolyzed gluten in an amount of about 1% to 65% by weight, preferably 14% to 65% by weight, of the total dry weight of the coating. In a particular embodiment, the hydrolyzed gluten wheat has a degree of hydrolysis of 0.5 to 5%. The coating composition may further comprise native wheat gluten and / or wheat flour. In a more particular embodiment, the coating composition as defined above consists of hydrolyzed gluten in an amount of 1% to 65% by weight of the total dry weight and native gluten in an amount of 35% to 99% by weight of the total dry weight.

[0019] In a second embodiment, the present invention relates to a method for producing a coating composition as defined above, comprising the following steps: 1) Providing natural wheat gluten; 2) Hydrolysis of wheat gluten to obtain a degree of hydrolysis (DH) of 0.5% to 5%; 3) mixing the hydrolyzed wheat gluten with other compounds to provide between 1% and 65% by weight of the total dry weight of the hydrolyzed wheat gluten; 4) Optionally, drying the mix obtained in step 3.

[0020] A third embodiment is a fried food product comprising a foodstuff coated with the coating composition defined above.

[0021] A final embodiment relates to a method of preparing a fried food product comprising the steps of coating a food product with a base-coating composition as defined above, coating the base-coated food product with a batter composition, and coating the batter-coated food product with a breading composition. [Brief description of the drawings]

[0022] [Figure 1] 1 shows a photograph of fried foods obtained with coatings of different compositions, below which is a description of the state of the batter skin of the fried foods and the texture of the batter skin. [Diagram 2]5 shows photographs of fried foods obtained with different amounts of flour containing hydrolyzed gluten wheat. [Diagram 3] Photographs of fried foods obtained by coating with a mix of gluten and hydrolyzed gluten and with wheat flour are shown. [Figure 4] Photographs of fried foods obtained using a mixture of gluten and hydrolyzed gluten and a wheat flour coating after storage for 4 and 5 hours under a high-temperature showcase at 60° C. are shown. [Diagram 5] The photographs show fried foods coated with a mixture of gluten and hydrolyzed gluten and with wheat flour, which were flash frozen at -40°C for 1 hour and then reheated at 220°C for 10 minutes in a conventional oven. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The first embodiment is a coating composition for fried foods, comprising hydrolyzed gluten in an amount of 1% to 65% by weight, preferably 14% to 65% by weight, based on the total dry weight of the coating. As shown in the examples, the inventors have demonstrated that the use of hydrolyzed gluten in the coating of the present invention improves the texture and color of fried foods, even in very small amounts of about 1%.

[0024] In this application, "mabushi" should be understood as a blend or pure powder composed of finely ground ingredients. Mabushi is usually applied as the first layer of a batter skin system, as it prepares the surface of the filling so that the rest of the system can be "built" on top of it. Shimo-mabushi may be pre-made or made for a specific product or process. They are usually flour-based, but may contain additional agents to help the batter skin better bind to the filling.

[0025] Typical dustings used in the food industry are wheat flour, rice flour, tapioca flour, corn starch or potato starch.

[0026] In the present application, "hydrolyzed gluten" should be understood as hydrolyzed vital wheat gluten (see its definition below) and as a reduction in the molecular weight of the proteins that make up wheat gluten. To hydrolyze wheat gluten, the skilled artisan can choose between all currently known processes, including chemical processes, such as acid hydrolysis or alkaline hydrolysis, or biochemical processes, such as proteases, peptidases.

[0027] In a preferred embodiment, the hydrolyzed wheat is characterized by a degree of hydrolysis (DH) of 0.5% to 5%, preferably 1% to 4%, more preferably 2% to 3%. The degree of hydrolysis is defined as the percentage of broken peptide bonds in the protein hydrolysate. The degree of hydrolysis can be easily determined using well-known protocols such as the o-phthaldialdehyde (OPA) or trinitrobenzenesulfonic acid (TNBS) colorimetric method. In the present application, the preferred method is OPA.

[0028] In a preferred embodiment, the coating composition also contains only wheat gluten, preferably hydrolyzed wheat gluten, free of wheat gluten and other compounds.

[0029] In the present application, "wheat gluten" should be understood as native wheat gluten, which is one of the most abundant proteins in the wheat crop, composed of gliadin and glutenin. Native gluten should be understood as gluten obtained by a process that does not denature wheat gluten and maintains its viscoelastic properties. In other words, native wheat gluten is also known as vital gluten.

[0030] In another preferred embodiment, the dusting also includes wheat flour.

[0031] In this application, "wheat flour" should be understood as wheat seeds that have been milled to reduce particle size. Wheat flour can be processed internally or purchased on the commercial market.

[0032] A second embodiment is a method for producing mabushi as described above, comprising the steps of: 1) providing wheat gluten; 2) hydrolyzing the wheat gluten to reach a DH of 0.5%-5%, preferably 1%-4%, more preferably 2%-3%; 3) mixing the hydrolyzed wheat gluten with other compounds to reach a content of 1%-65%, preferably 14-65%; and 4) optionally drying the mixture.

[0033] The first step consists of providing wheat gluten. Wheat gluten can be purchased on the commercial market. It can be natural or vital. Wheat gluten can also be extracted from wheat seeds. To extract natural gluten, those skilled in the art generally use known processes.

[0034] The second step consists of hydrolyzing the wheat gluten. The first solution may be the use of acid or alkaline reagents to reduce the size of the gluten. The second solution, which is more preferred, may be the use of proteases and / or peptidases. The enzymes selectively cleave the amino acid bonds and reduce the protein molecular weight. In a preferred embodiment, the enzyme is Neutrase, a protease produced from Bacillus amyloliquefaciens broth. The hydrolysis protocol consists of 1) adding a selected amount of protease to the native gluten, 2) adjusting the temperature and pH at the enzyme optimum, 3) carrying out the hydrolysis by homogenizing the gluten / enzyme mix and checking the degree of hydrolysis, and 4) stopping the reaction by adjusting the pH far from the optimum when the correct degree of hydrolysis is reached.

[0035] The third step consists of mixing the hydrolyzed wheat gluten with other compounds.

[0036] The other compounds may preferably be selected from the list: wheat gluten, wheat flour. In a more preferred embodiment, the other compounds consist of gluten and / or wheat flour.

[0037] The mixing can be carried out wet with sufficient stirring and homogenizing power, or it can be carried out dry with the aid of known selected equipment.

[0038] In the mixture, the hydrolyzed wheat gluten comprises from 1% to 65%, preferably from 14% to 65%, of the total dry matter of the coating composition.

[0039] The fourth optional step consists of optional drying to remove residual water and optimize shelf life stability. This step is necessary especially if the mixing is done wet. The dry matter of the mix should be increased to more than 80%, preferably more than 85%, more preferably more than 90%.

[0040] Another embodiment is the industrial use of such coatings for deep frying.

[0041] The present invention also relates to a method for preparing fried food products and fried foods comprising a foodstuff coated with a coating composition as defined above, the method comprising the steps of coating a food product with a coating composition as defined above, coating the coating-coated food product with a batter composition, and coating the batter-coated food product with a breading composition.

[0042] The present invention will be better understood with the aid of the following detailed description of the embodiments. EXAMPLES

[0043] In the following examples, a commercially available hydrolyzed wheat gluten from Roquette Freres is used, which contains 88.5% protein (N6,25 method) and has a DH of 2.5 (OPA method).

[0044] Example 1: Effect of using hydrolyzed wheat gluten in coating on the quality of fried foods The different products listed in Table 1 used as drenches are compared. [Table 1]

[0045] As the second layer, the coating composition in Table 2 below is used for all samples. [Table 2]

[0046] Water is added to the powder in a ratio of 1.5 / 1 and the mix is ​​homogenized.

[0047] As the third layer, the crumb composition in Table 3 below is used for all samples. [Table 3]

[0048] The process of obtaining fried chicken is as follows: Coat the surface of the chicken pieces with each of the ingredients listed in Table 1. They are then dipped in batter and the surface is then coated with breadcrumbs. Fry at 180℃ for 5 minutes. Store in a high temperature showcase (60℃) for 0 to 9 hours.

[0049] Take a photo and evaluate the condition / texture of the batter skin (Figure 1).

[0050] The use of hydrolyzed gluten at 8% in wheat flour improves the coating properties. The adhesion and texture of the batter skin are similar to those of oil-coated starch (Amusko KI) coatings. The use of a mix of gluten and hydrolyzed gluten can also give good results, and all the starch can be removed from the coating (Figure 1).

[0051] The results are summarized in Table 4 below. [Table 4]

[0052] By incorporating hydrolyzed gluten into the coating, fried chicken can maintain its original texture even when stored in a high-temperature showcase, and the storage time can be increased fourfold.

[0053] Example 2: Effect of hydrolyzed wheat gluten on the quality of fried foods Different dosages of hydrolyzed wheat gluten (Nutralys® W from Roquette) in the flour are compared as a dusting. [Table 5]

[0054] The recipe for the batter and breadcrumbs is the same as in Example 1.

[0055] The process of obtaining fried chicken is as follows: Sprinkle ingredients evenly over surface of chicken. They are then dipped in batter and the surface is then coated with breadcrumbs. Fry at 180℃ for 5 minutes.

[0056] Photographs were taken and the condition and texture of the batter was evaluated after storing it in a high-temperature showcase (60°C) for 2.5 hours (Figure 2).

[0057] Texture and color were rated and are summarized in Table 6 below. [Table 6]

[0058] A dosage consisting of about 1% to 60% hydrolyzed wheat gluten in the coating makes it possible to reach a good texture and color of the fried chicken. Surprisingly, the use of a very small amount of hydrolyzed gluten in the coating (about 1%) allows an improvement in the texture.

[0059] Example 3: Performance of a mixed gluten and hydrolyzed gluten coating compared to wheat flour coating. The different powder mixtures listed in Table 7 below are compared as dustings. [Table 7]

[0060] The recipe for the batter and breadcrumbs is the same as in Example 1.

[0061] The process of obtaining fried chicken is as follows: Sprinkle ingredients evenly over surface of chicken. They are then dipped in batter and the surface is then coated with breadcrumbs. Fry at 180℃ for 5 minutes.

[0062] Photographs were taken of fried foods made using the flour and mabushi useful in the present invention, and the condition and texture of the batter immediately after frying were evaluated (Figure 3). The yield rate, which is the percentage change in weight of the meat piece before and after frying, was also calculated.

[0063] [1] Photographs were then taken and the condition / texture of the crust was evaluated after 4.5 hours of storage under a hot showcase (60°C) (Figure 4). Weight variations were also tracked and expressed as a percentage (1=100%), and compared to fried foods using wheat flour as the crust, those using gluten and / or hydrolyzed gluten crusts are improved in terms of preservation under heat. Furthermore, fried foods using crusts containing a combination of gluten and hydrolyzed gluten are closest to the control, with a crust that is not too rough and the food inside being as moist as the control.

[0064] Additionally, fried chicken is flash frozen at -40°C for one hour and then reheated in a conventional oven at 220°C for 10 minutes.

[0065] When gluten / hydrolyzed gluten mix is ​​used as a coating, less juice is released by the fried chicken when frozen / reheated (Figure 5), and compared to fried chicken using wheat flour as a coating, the present invention has better mouth melt and the coating skin is good and not too thick. The problem with fried chicken using gluten coating is that it also gives a bad organoleptic experience in the mouth due to the feeling of a thin film coating skin on the food. Fried chicken using hydrolyzed gluten coating becomes too hard and separates from the food too easily, and also has a bad organoleptic perception.

Claims

1. A coating composition for fried foods, comprising 1% to 65% hydrolyzed wheat gluten by weight of the total dry weight of the coating composition; A coating composition, wherein the hydrolyzed wheat gluten has a degree of hydrolysis of 0.5% to 5%.

2. 10. The coating composition of claim 1 comprising native wheat gluten.

3. A coating composition according to claim 1 or 2, comprising wheat flour.

4. 3. The coating composition according to claim 1 or 2, which comprises from 1% to 65% by total dry weight of said hydrolyzed wheat gluten and from 35% to 99% by total dry weight of native gluten.

5. 1) providing native wheat gluten; 2) hydrolyzing wheat gluten to obtain a degree of hydrolysis (DH) of 0.5% to 5%; 3) mixing the hydrolyzed wheat gluten with other compounds to provide a total dry weight of the hydrolyzed wheat gluten of 1% to 65% by weight; 4) Optionally, drying the mix obtained in step 3. A method for producing a coating composition according to any one of claims 1 to 4, comprising the steps of:

6. A fried food product comprising a foodstuff coated with the coating composition of any one of claims 1 to 4.

7. 1. A method for preparing fried foods, comprising: Coating a food product with a coating composition according to any one of claims 1 to 4; coating the coated food product with a batter composition; and coating the batter composition coated food product with a breading composition.

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