JP7748830B2 - Fried food manufacturing method - Google Patents

Description

The present invention relates to a method for producing fried foods that have a textured tempura-like appearance and maintain their texture after cooking.

Prepared fried foods, which are sold mainly in convenience stores and the prepared food sections of supermarkets, are required to have a crispy texture and to maintain that texture for a long period of time. Known methods for imparting a crispy texture to fried foods include mixing granular breadcrumbs, cracker crumbs, etc. into the coating (see, for example, Patent Document 1). Furthermore, reported methods for maintaining the texture of fried foods include using coating materials containing sugar alcohols (Patent Document 2) and egg white powder (Patent Document 3).

Japanese Patent Application Publication No. 11-46712 Japanese Patent Application Laid-Open No. 2000-300198 Japanese Patent Application Laid-Open No. 2002-78460

However, the method described in Patent Document 1 makes it difficult to maintain the texture for a long period of time. Furthermore, fried foods with an even crispier texture than those produced by the methods described in Patent Documents 2 and 3 are desired. Therefore, an object of the present invention is to provide a method for producing fried foods that have a crispy texture and that maintain that texture for a long period of time.

The inventors discovered that in the production of fried foods, fried foods with a crispy texture can be obtained by dividing the coating material into batter and breading powder, adding alginic acids and divalent metal salts to each, and maintaining a constant viscosity of the batter, leading to the completion of the present invention.

That is, the present invention provides the following.
(1) The following steps:
(i) applying a batter liquid to the entire surface of the food material, the batter liquid containing alginic acids and having a viscosity of 2000 to 20000 mPa s;
(ii) applying breading flour to the entire surface of the food material of (i), wherein the breading flour comprises a divalent metal salt; and (iii) frying the food material of (ii).
(2) The method according to (1), wherein the frying in step (iii) is started within 30 minutes after step (ii).
(3) The method according to (1) or (2), wherein the concentration of alginic acids contained in the batter is 0.15 to 0.8% by weight.
(4) The method according to any one of (1) to (3), wherein the amount of the divalent metal salt contained in 100 parts by weight of the breading powder is 0.1 to 3.0 parts by weight.
(5) A fried food produced by the method according to any one of (1) to (4).

The present invention provides a method for producing fried foods that have a crispy texture that is maintained for a long period of time.

1 is a photograph showing the appearance of fried chicken from Test Example 6 in Example 1. 1 is a photograph showing the appearance of fried chicken from Test Example 10 in Example 1.

In this specification, "A to B" (A and B are numerical values) means "greater than or equal to A and less than or equal to B" unless otherwise specified. In this specification, "%" means "weight %" unless otherwise specified.

1. Method for Producing Fried Food The method for producing fried food of the present invention (hereinafter also referred to as "the method of the present invention") is characterized by comprising the following steps:
(i) applying a batter liquid to the entire surface of the food material, the batter liquid containing alginic acids and having a viscosity of 2000 to 20000 mPa s;
(ii) applying breading flour to the entire surface of the food material of (i), wherein the breading flour comprises a divalent metal salt; and (iii) frying the food material of (ii).

As used herein, "fried food" refers to food obtained by deep-frying ingredients. Specific examples include fried chicken, tempura, cutlets, and fritters. While fried foods may be food directly deep-fried, they typically refer to food that has been deep-fried with its surface covered in a coating. As used herein, "food" refers to the substance of the food to be deep-fried, specifically a single ingredient such as meat, fish, or vegetables that has been pre-processed, or a mixture of ingredients that has been cooked and shaped. As used herein, "coating material" refers to a coating used to coat ingredients before deep-frying, and primarily serves the purposes of imparting a crispy texture after cooking and preventing overheating of ingredients. Coating materials can be broadly divided into liquid batters (batter liquid) and powdered breading materials (breading powder).

1-1 Process (i)
Step (i) of the method of the present invention is a step of applying batter to the entire surface of the food material. The batter is applied to the food material, which has been pre-treated, washed, shaped, etc. as necessary. The application method is not particularly limited as long as it can be applied so that the entire surface of the food material is covered with batter to a certain thickness or more. Any method such as immersion, shower application, or brush application can be used, but immersion application is particularly preferred. Alternatively, the batter can be applied automatically using a battering machine.

In this specification, "batter" refers to a liquid coating material, and is not particularly limited, but is typically prepared by dissolving flour, starch, oils and fats, seasonings, spices, etc. in water. In addition to these, batter may also contain leavening agents, emulsifiers, thickening polysaccharides, colorings, pH adjusters, etc.

In the method of the present invention, the batter contains alginic acids at a concentration of 0.15 to 0.8% by weight, preferably 0.3 to 0.7% by weight. In this specification, "alginic acids" includes any substance having an alginic acid skeleton, such as alginic acid, alginate salts, and propylene glycol alginate, with alginate salts being particularly preferred. Alginate salts include both monovalent metal alginate salts and polyvalent metal alginate salts, with monovalent metal alginate salts and sodium alginate being particularly preferred. The molecular weight of the alginic acid skeleton is preferably 50,000 to 5,000,000 (250-25,000-mer), and particularly 120,000 to 150,000 (600-750-mer).

In the method of the present invention, the viscosity of the batter is 2,000 to 20,000 mPa·s, preferably 3,000 to 10,000 mPa·s. In this specification, "viscosity" refers to the liquid viscosity (Pascal-seconds) defined in JIS Z 8803:2011. Viscosity can be measured, for example, using a rotational viscometer (e.g., Model BM or Model TVC-7 manufactured by Toki Sangyo Co., Ltd.). Because the batter has the above viscosity, when applied to food materials by immersion or the like, it can be more easily maintained on the surface of the food materials as a layer of a certain thickness or greater.

1-2 Process (ii)
Step (ii) of the method of the present invention is a step of applying breading powder to the entire surface of the food material coated with the batter in step (i). The method of applying breading powder is not particularly limited, but for example, the food material coated with the batter is placed in a flat container such as a tray containing breading powder, and then breading powder is applied from above, or a flour duster or a breading machine can be used.

In this specification, "breading flour" refers to a powdered coating material and is not particularly limited, but is usually prepared by mixing powders of wheat flour, starch, oils and fats, seasonings, spices, etc. In addition to these, breading flour may also contain leavening agents, emulsifiers, thickening polysaccharides, colorings, etc. Furthermore, breading flour may also be mixed with breadcrumbs, cracker flour, rice flour, corn flour, or corn grits to increase the crispiness of the texture.

In the method of the present invention, the breading flour contains a divalent metal salt in an amount of 0.1 to 3.0 parts by weight, preferably 0.5 to 2.0 parts by weight, per 100 parts by weight. As used herein, "divalent metal salt" is not particularly limited as long as it is usable as a food additive, but calcium salts and magnesium salts, with calcium salts being particularly preferred. When calcium salts are used, the amount of calcium contained in the breading flour is preferably 0.02 to 1.5% by weight, and particularly preferably 0.1 to 1.0% by weight. The calcium salt is not particularly limited, but examples include calcium carbonate, calcium lactate, calcium chloride, calcium acetate, and calcium phosphate. Calcium carbonate is particularly preferred, as it has little effect on taste and has a slow reaction rate with alginic acid, as described below.

In step (ii) of the present invention, the alginic acids in the batter applied in step (i) come into contact with the divalent metal salt in the breading powder, forming a gel-like film of divalent metal alginate at the boundary between the batter and the breading powder.

The particle size of the breading flour is not particularly limited, but can be, for example, 20 to 100 mesh. If the breading flour has a sufficiently fine particle size, it can be applied more evenly to cover the layer of batter on the surface of the food material.

In step (ii) of the present invention, the alginic acids in the batter liquid applied in step (i) come into contact with the divalent metal salt in the breading powder, forming a gel-like film of divalent metal alginate at the boundary between the batter liquid layer and the breading powder layer. As a result, the batter liquid remains as a liquid layer without mixing with the breading powder inside the film. However, as time passes after the breading powder is applied, the thickness and hardness of the film that is formed increase, and eventually the entire batter liquid layer gels over time. For this reason, it is desirable to keep the time required for step (ii) as short as possible. The time required for step (ii) is not particularly limited, but it is preferable to keep it within 30 minutes, particularly within 10 minutes, within 5 minutes, or within 1 minute.

1-3 Process (iii)
Step (iii) of the method of the present invention is a step of deep-frying the food material coated with breading powder in step (ii). As mentioned above, when the batter liquid and breading powder are brought into contact with each other, a gel-like film is formed at their boundary, and the batter liquid remains liquid within the film. When this is heated (deep-frying), the batter liquid moves within the film, forming a wavy pattern on the surface of the batter. Furthermore, small ruptures occur in places, especially in areas where the batter liquid layer moves within the film and accumulates, forming lumps, forming even more complex irregularities on the surface of the batter. Heating a batter with such a complex irregularity imparts a crispier texture to the surface than usual. Because the outermost surface of this irregularity is far from the food material, it is less susceptible to the moisture inside the food material, making it easier to maintain a crispy texture.

As used herein, "frying" refers to a cooking technique in which food ingredients are heated by contacting them with heated edible oils and fats. The edible oils and fats used are not particularly limited as long as they are oils and fats typically used in frying, and can include soybean oil, rapeseed oil, canola oil, sunflower oil, olive oil, corn oil, cottonseed oil, coconut oil, sesame oil, lard, beef tallow, palm oil, etc., or mixtures of these. "Edible oils and fats" as used here includes not only the above-mentioned oil and fat materials themselves, but also oil and fat compositions in which emulsifiers, antioxidants (e.g., vitamin E), etc., have been added to the above-mentioned oil and fat materials. It is desirable to use an amount of edible oil and fat when frying that exceeds the amount sufficient to completely submerge the food ingredients being cooked.

The frying temperature varies depending on the ingredients being cooked, and is not particularly limited, but can be set to 150-200°C, especially 160-180°C. The frying time is also not particularly limited, but can be set to 0.5-10 minutes, especially 1-7 minutes.

It is preferable to deep fry within 30 minutes, particularly within 10 minutes, 5 minutes, or 1 minute after the breading powder has been applied to the entire surface in step (ii). As mentioned above, the film at the boundary between the batter liquid layer and the breading powder layer formed after step (ii) becomes thicker and harder over time. As the film becomes thicker and harder, it becomes less likely that the unevenness of the batter surface, such as that caused by the movement or rupture of the batter liquid layer, will occur, as described above.

After frying, the ingredients are removed from the cooking oil and the excess oil is drained off to obtain fried food.

1-4 Other Steps The method of the present invention may include a step of packaging or storing the fried food obtained in step (iii). The method of the present invention may also include other steps before step (i), between steps (i), (ii), and (iii), and/or after step (iii). The other steps are not particularly limited, and may include, for example, a step of applying a different breading powder that does not contain a divalent metal salt to the food material before step (i). Furthermore, after step (i), a step of removing excess batter liquid adhering to the surface of the food material (a step of draining excess liquid) may also be included. Furthermore, after step (ii), a step of removing excess breading powder adhering to the surface of the food material (a step of brushing off excess powder) may also be included.

For example, the method of the present invention may include a step of marinating the food material before step (i). The marinating step may involve immersing the food material in a seasoning liquid, sprinkling powdered seasoning on the food material, or the like. In addition to or instead of this, the method may include a step of dusting the food material with flour. The dusting powder is not particularly limited, but examples include potato starch, wheat flour, etc.

Step (ii) may be repeated multiple times. In this case, it is desirable that the time required for the process not be too long.

For example, the method of the present invention may include a step of heating the food material by applying steam at a temperature above 100°C (e.g., 150-170°C) after step (iii). While the food material may be heated only by deep frying, depending on the food material, the inside may not be heated sufficiently and the coating may burn. By adding a steam heating treatment, it is possible to heat the food material thoroughly to the inside without burning the coating.

The fried foods produced according to the present invention may be flash-frozen for storage and distribution, if necessary. Flash-freezing makes it easier to store and distribute the fried foods while maintaining the crispy texture of their surface. Frozen fried foods can be made edible by, for example, cooking them again with heat, such as frying.

2. Fried Food The fried food of the present invention is characterized by being produced by the method of the present invention. By being produced by the method of the present invention, the fried food of the present invention has a batter surface with a complex wavy structure.

The ingredients and coating materials used in the fried food of the present invention are as described in "1. Method for producing fried food."

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

[Example 1] Study of batter viscosity (1)
A mixed flour (containing wheat flour, vegetable oil, spices, seasonings, leavening agents, emulsifiers, thickening polysaccharides, and paprika pigment) was prepared, and 1 part by weight of sodium alginate was added to 100 parts by weight of the mixed flour and mixed uniformly. 140, 150, 155, 160, 170, 180, 200, 220, 270, or 320 parts by weight of water was added to the mixed flour and mixed with a whisk for 1 minute to prepare various batters. The viscosity of each batter was measured using a rotational viscometer (Model BM or Model TVC-7, manufactured by Toki Sangyo Co., Ltd.). The viscosities of the various batters are shown in Table 1.

100 parts by weight of the mixed powder was added to 1 part by weight of calcium carbonate powder and mixed uniformly to prepare breading powder. The particle size of the breading powder was 80 mesh.

Chicken thigh meat was cut into pieces approximately 60g in size, soaked in a marinade liquid (containing seasonings, egg white, starch, and water), and tumbled for 1 hour. After draining the liquid, the meat was dusted with starch. Batter was placed in a tray, and the floured meat was dipped into the liquid to coat the entire surface of the meat. The meat was then coated with breading flour. The weight of the coated material was approximately 10g per piece of meat. The time required from start to finish of applying the breading flour was approximately 30 seconds.

The coated meat was placed in 170°C cooking oil within 1 minute of coating, deep-fried for 4 minutes and 30 seconds, and then removed from the cooking oil. The appearance of the meat (fried chicken) immediately after removal and the texture of the fried chicken 30 minutes after removal were evaluated. The evaluation results for appearance and texture were a composite of the evaluation results of five panelists. The evaluation criteria are shown in Table 2. The evaluation results for each fried chicken are shown in Table 1. Figure 1 shows a photograph of the appearance of the fried chicken from Test Example 6, and Figure 2 shows a photograph of the appearance of the fried chicken from Test Example 10.

As shown in Table 1, when the viscosity of the batter was approximately 2,320 to 19,000 mPa·s, and particularly 3,260 to 8,380 mPa·s, tempura-like irregularities were formed on the surface of the fried chicken, and a good texture was maintained.

[Example 2] Study on batter viscosity (2)
Fried chicken was prepared in the same manner as in Example 1, except that the amount of sodium alginate added to the batter was increased to 2 parts by weight per 100 parts by weight of the mixed flour, and the amount of water added was the amount shown in Table 3. The viscosities of the various batters are shown in Table 3. The appearance of the fried chicken immediately after frying and removing it from the cooking oil, and the texture of the fried chicken 30 minutes after removal were evaluated in the same manner as in Example 1. The evaluation results for each fried chicken are shown in Table 3.

As shown in Table 3, when the viscosity of the batter was approximately 2,570 to 18,500 mPa·s, and particularly 4,500 to 10,000 mPa·s, the surface of the fried chicken was uneven and a good texture was maintained.

[Example 3] Study on sodium alginate concentration Fried chicken was prepared in the same manner as in Example 1, except that the amounts of sodium alginate and water added to the batter were changed as shown in Table 4. The viscosities of various batters are shown in Table 4. The appearance of the fried chicken immediately after frying and removing it from the cooking oil, and the texture of the fried chicken 30 minutes after removal were evaluated in the same manner as in Example 1. The evaluation results for each fried chicken are shown in Table 4.

As shown in Table 4, the viscosity of the batter was 3800 to 5000 mPa·s, which was roughly the same for all test examples. When the sodium alginate concentration in the batter was around 0.18 to 0.80% by weight, particularly around 0.34 to 0.60% by weight, an uneven surface was formed on the fried chicken, and a good texture was maintained.

[Example 4] Investigation of various calcium salts Fried chicken was prepared in the same manner as in Example 1, except that the same batter liquid as used in Test Example 23 of Example 3 was used, and the type and amount of calcium salt mixed with the breading powder were changed as shown in Table 5. The appearance of the fried chicken immediately after deep-frying and removing from the cooking oil, and the texture of the fried chicken 30 minutes after removal were evaluated in the same manner as in Example 1. The taste of each fried chicken was evaluated by five panelists using the evaluation criteria shown in Table 2, and the results were combined. The evaluation results for each fried chicken are shown in Table 5.

As shown in Table 5, the fried chicken made using any of the calcium salts contained in breading flour had an uneven surface and maintained a good texture. On the other hand, the fried chicken made using calcium chloride had a bitter and astringent taste that is characteristic of calcium chloride.

[Example 5] Study on the time until frying after coating Fried chicken was cooked in the same manner as in Example 1, except that the same batter liquid as used in Test Example 23 of Example 3 was used and the time until frying after coating was set to the time shown in Table 6. The appearance of the fried chicken immediately after removal from the cooking oil and the texture of the fried chicken 30 minutes after removal were evaluated in the same manner as in Example 1. The evaluation results for each fried chicken are shown in Table 6. As shown in Table 6, the shorter the time until frying after coating, the more irregularities formed on the surface of the fried chicken and the better the texture was maintained.

Claims (4)

The following steps:
(i) applying a batter liquid to the entire surface of the food material, the batter liquid containing alginic acids and having a viscosity of 2000 to 20000 mPa s;
(ii) applying breading flour to the entire surface of the food material of (i), wherein the breading flour comprises a divalent metal salt; and (iii) frying the food material of (ii ) ,
The frying in step (iii) is initiated within 30 minutes after step (ii);
Methods for producing fried foods. 2. The method of claim 1, wherein the frying in step (iii) is initiated within 1 minute after step (ii). The method of claim 1 or 2, wherein the concentration of alginic acids contained in the batter is 0.15 to 0.8% by weight. The method described in any one of claims 1 to 3, wherein the amount of divalent metal salt contained in 100 parts by weight of the breading flour is 0.1 to 3.0 parts by weight.