JPS6043106B2 - Method for producing fried tofu-like foods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for producing fried tofu-like foods, and in particular, to produce fried tofu-like foods without going through the tofu manufacturing process and without using any coagulating agents such as bittern. This relates to an improvement method.

Traditionally, so-called "deep-fried tofu" was produced by cutting hard tofu into thin slices and frying them, but in recent years, this method has been replaced with a method using heat-coagulable soybean protein as a coagulant. A method for producing fried tofu-like foods that eliminates the use of
8-80263, 50-88255 and 41-51
541 Publication)).

However, in such methods, a method of frying the molded product in multiple stages or a continuous fryer frying method is adopted, and since heat transfer from the oil to the molded product occurs from the surface part during frying, the inside does not expand sufficiently. The defect is that the surface part hardens due to dehydration and the swelling is suppressed, so that it is not possible to obtain a good swelling and degree of swelling in terms of structure, and the degree of swelling in the center becomes extremely poor, especially if the material is thick. existed. In order to eliminate such defects, the present inventors have conducted various studies on a deep-fried tofu method that utilizes heat-coagulable soybean protein and does not go through the tofu manufacturing process, and as a result, they have discovered a kneaded molded product that uses heat-coagulable soybean protein as the main raw material. First, microwave dielectric heating is performed to perform swelling treatment, and then one-stage deep-frying treatment is performed, or microwave dielectric heating is continued to perform partial dehydration and surface hardening, so that a good tissue swelling state is obtained, and flavor is obtained. He discovered that it was possible to produce a good fried tofu-like food with excellent gloss etc., and applied for a patent.
1-110419, Japanese Unexamined Patent Publication No. 53-3495). Thereafter, as a result of various studies regarding this method, the following findings were obtained and the present invention was completed. (1) By appropriately selecting the preparation conditions for thermocoagulable soybean protein material, the degree of swelling during microwave dielectric heating can be significantly increased; (2)
) If the degree of swelling is increased as described above and the product is puffed excessively, the vacuoles in the internal tissue of the product will become extremely large and the texture will become rough.
(3) The above-mentioned excessive puffing can be avoided by appropriately setting the blending amount of okara, or by adding an appropriate amount of concentrated denatured soybean protein instead of okara. or by substituting a part of the heat-coagulable soybean protein substance with the concentrated modified soybean protein, and the degree of swelling can be controlled within an appropriate range.

The thermocoagulable soybean protein substance used as the main raw material in the present invention refers to soybean protein-derived substances used in the production of tofu, including soybean flour, defatted soybean flour, dried soymilk, Extracted soy protein, isolated soy protein, etc. or mixtures thereof are included. A typical example of a thermocoagulable soybean protein substance that causes excessive expansion during microwave dielectric heating is extracted soybean soy milk that is vacuum concentrated at a temperature of 55°C or lower and heated to 70°C.
Below, there is dried soy milk obtained by instant sterilization under conditions of 2 to 3 seconds and spray drying. The degree of thermal denaturation is lower than that of commercially available soybean protein that is spray dried. Furthermore, the concentrated modified soybean protein used in place of or in combination with okara in the present invention is produced by removing water-soluble sugars, ash, etc. from defatted soybean flakes or defatted soybean flour with water, dilute acid, and solvent. It refers to proteins that have been denatured and insolubilized, which are generally referred to as concentrated proteins with a protein content of 70% or more in dry matter. It is generally produced by heating defatted soybean flakes or defatted soybeans in the presence of water to denature and insolubilize the protein, washing with water, drying, and then pulverizing. However, after washing defatted soybean flakes or defatted soybeans with a water-soluble organic solvent such as 20% to 80% alcohol to remove solvent-soluble substances such as carbohydrates and minerals, or after washing with dilute acid and washing with water. It includes all products produced through a process of denaturing proteins in the production method of concentrated proteins, such as those produced by heating in the presence of a protein to denature and insolubilize the protein. On the other hand, 1 used in the present invention
Okara refers to the dregs after squeezing one soybean milk prepared by the usual method, or the okara etc. produced when producing soybean protein products such as normal extracted protein and isolated protein. This okara is usually used by grinding it with a grinder such as a roll mill or a ball mill. Next, the procedure for carrying out the present invention will be explained.First, an appropriate amount of okara and/or concentrated modified soybean protein powder is added to a heat-coagulable soybean protein material, and then water is added and kneaded.

The amount of water added is such that the resulting kneaded product is integrated into a paste-like form and does not flow when placed on a flat surface. Next, if necessary, other appropriate edible auxiliary raw materials such as fats and oils and egg components are added and used, but the amount of these additions is within the range that allows the subsequent preparation of the kneaded product. The paste-like kneaded material is then molded into any shape such as a flat plate, rod, or circular shape, and the molded dough is left at room temperature for about 3 days or more while preventing the surface from drying, and then soaked in water. Measures the affinity between protein and protein. Further apply oil and fat to the surface of this formed dough,
Alternatively, after the formed dough is immersed in oil and expanded by microwave dielectric heating, the dough is taken out and the expanded dough is partially dehydrated, surface hardened, and oil flavored at 140~
Heating in oil at 200°C, preferably 140-160°C,
To obtain an extremely excellent fried tofu-like product in which the surface of the puffed dough is golden brown, the flavor, color, and degree of puffing are controlled to the desired level, and the vacuoles of the internal structure are evenly arranged and the texture is fine. Alternatively, microwave dielectric heating pre-treatment is performed while the dough is immersed in oil, and after the dough has expanded, microwave dielectric heating is continued without taking it out from the microwave dielectric heating device, essentially frying the dough (soot and oil). ), expand it to the desired size, perform partial dehydration of the dough, perform surface hardening treatment, and impart oil and fat flavor, i.e., by a manufacturing method that does not require a single frying process after microwave dielectric heating treatment. Similarly, the degree of swelling is suppressed and adjusted to the desired level, the vacuoles of the internal tissue are uniform in size, and the texture is fine.
It is possible to produce fried tofu-like foods with good flavor and color. Table 1 shows the differences in the swelling degree of the blended products due to the difference in the dry soybean milk as the main heat-coagulable soybean protein substance, and when kara and/or concentrated denatured soybean protein are added to the dried soymilk at various levels of addition. The swelling degree is determined by the method of the present invention, which involves one-stage deep-frying following the swelling treatment by microwave dielectric heating, and the conventional method, 2.
The results of a comparison of the Yang combination of the tiered oil frying method are shown. However, the degree of swelling in the table is the value obtained by dividing the product of the vertical dimension x lateral dimension of the product after swelling by the product of the vertical dimension x lateral dimension of the kneaded dough before swelling. Sample No. l and no. 2 is a comparison of the degree of swelling in formulations that do not contain okara or concentrated denatured soybean protein. Sample No.
．． The heat-coagulable soybean protein material used in 1 is commercially available dried soymilk (4.5% moisture), and its preparation conditions are as described above, with a degree of swelling of 3.8 and an internal structure. The result is a fine-grained product with uniformly sized vacuoles. On the other hand, sample No. 2~NO. The thermocoagulable soybean protein material used in step 7 is a prototype product with a low degree of heat denaturation obtained by concentrating soymilk at 55°C or lower, then instant sterilizing it at 70°C or lower for 2 to 3 seconds, and then spray drying. dried soy milk (moisture 5
．． 0%). Sample No. The swelling degree of the control product of sample No. 2, which was formulated only with dried soy milk and subjected to conventional two-stage deep-frying, was 2.5. It is the same level as 2.2 when frying in two stages of 1, and there is no big difference, and there is also a defect that the center is not puffed.

On the other hand, sample No. When No. 2 was subjected to microwave dielectric heating according to the method of the present invention, the swelling degree significantly increased to 6.3. This marked increase in the degree of swelling was observed in sample No. Compared to the soybean protein in the commercially available dry soymilk used in Sample No. This is thought to be because the soybean protein in the dried soymilk of the prototype used in step 2 is in a more undenatured state due to the low-temperature treatment, and because the degree of swelling is further increased by internal preliminary heating using microwave dielectric heating. However, when the degree of swelling is 6.3, the vacuoles in the internal tissue are excessive and irregular, and the texture is rough, so it cannot be said to be a desirable product. Sample No. 3
~NO. 5 and NO. The okara added in step 7 is a paste with a moisture content of 75% that has been ground in a roll mill. is about 80%. Sample No. 6 and NO. The concentrated denatured soybean protein (moisture 2.0%) used in No. 7 is a commercially available product, and its fineness is such that when passed through a 200-mesh Japanese Industrial Standard sieve, the amount (weight) passing through is 80% or more. Sample No. 3~N
O. In No. 5, a dough formulation was used in which the above-mentioned okara paste was added to the dry soybean milk prototype with a low degree of thermal denaturation, which caused excessive puffiness, at various levels; in this comparative test, the amount of okara added was Sample No. corresponding to each. The swelling degree of 2 was changed from 4.9 to 3. ? I was able to control and control it.

The degree of puffing to obtain the preferable internal structure and fineness of the texture of the fried tofu-like food according to the method of the present invention is in the range of 3.0 to 4.5, and when the degree of puffing is 4.5 or more, there is a defect of excessive puffing. If it is less than 3.0, the degree of swelling is too small and the texture of the product is sluggish.

Furthermore, sample No. In No. 6, concentrated denatured soybean protein was added alone to the dry soybean milk prototype with a low degree of heat denaturation. In this case, as with okara, the degree of swelling is suppressed,
By changing the amount of concentrated denatured soybean protein added, the degree of swelling can be adjusted to 3.5, which is the same as when using okara.
It is possible to control the degree of swelling within a suitable range of 4.5 to 4.5. Furthermore, sample No. This is the case where okara and concentrated denatured soybean protein are used together in No. 7, and it has the same swelling suppressing and regulating effect as when either okara or concentrated denatured soybean protein is added alone. The appropriate swelling degree, that is, the swelling degree is 3.0 to 4.
The amount of soybean curd and/or concentrated denatured soybean protein necessary to suppress the soybean protein content to within the range of 5 depends on the type of soybean protein material having heat coagulability, its swelling performance, and the formulation of the kneaded product mainly containing it. Generally speaking, when okara is added alone to 100 parts by weight of the solid content of a soybean protein substance having heat coagulability, it is calculated as 4 to 2 parts by weight (with a water content of about 75%). In the case of adding concentrated denatured soybean protein alone, it is about 11 to 6 parts by weight (concentrated denatured soybean protein with a moisture content of 1 to 2%) in terms of solid content. It is about 11.2 to 68.4 parts by weight of soybean protein, and when okara and concentrated modified soybean protein are used together, it is necessary to add about 4 to 6 parts by weight in terms of solid content. be. The excessive swelling phenomenon of the thermocoagulable soybean protein material during microwave dielectric heating, which is subject to the swelling degree suppression or adjustment by the addition of okara and/or concentrated modified soybean protein of the present invention, is due to the above-mentioned low-temperature processing conditions. This problem occurs not only in dried soybean milk in which the soybean protein is in an undenatured state, but also due to differences in the rods of commercially available isolated proteins.

The reason for this is thought to be that subtle changes in the degree of heating during the manufacturing process affect the degree of denaturation of the separated protein. Table 2 shows the degree of swelling of separated proteins for different commercially available rods (sample NO.
．． l and NO. 2) difference and excessive swelling of sample No. 2
The degree of swelling obtained when adding okara (sample no. 3) or concentrated denatured soybean protein (sample no. 4) as described above is determined by the method of the present invention, in which swelling treatment by microwave dielectric heating is followed by one-stage deep-frying. The results of a comparative test are shown between the conventional two-stage deep-frying method and the conventional two-stage deep-frying method.

Sample No. 1 using isolated soybean protein from a commercially available rod.
Sample No. 1 showed an appropriate degree of swelling of 4.0 through dielectric heating swelling using microwaves and subsequent one-stage deep-frying treatment, but Sample No.
In No. 2, the swelling degree was 5.7 and an excessive swelling phenomenon occurred. Sample No. After microwave dielectric heating and one-stage deep-frying of a blended product (sample no. 3) in which okara paste was added to commercially available isolated soybean protein and a blended product (sample no. 4) in which concentrated denatured soybean protein was added (sample no. 4) from the same lot as 2. The degree of swelling is 4.0 and 3.7, respectively.
Therefore, it was possible to suppress and adjust it within an appropriate range.
The degree of grinding of the okara to be added is such that the amount of dried okara passing through a 200 mesh sieve according to the Japanese Industrial Standards is at least 10%, preferably at least 80%.

If the grain size of okara is coarse, the texture will be unpleasant when eaten. 200
This tendency is particularly strong when the amount passing through the mesh sieve is less than 38%, and even if the degree of swelling can be suppressed or adjusted within the desired range, the product will feel rough and have a feeling of foreign matter being mixed in when eaten. Undesirable.

In this way, the addition of appropriate amounts of kara and/or concentrated modified soybean protein prevents excessive expansion of thermocoagulable soybean protein material during microwave dielectric heating treatment, and subsequent conventional one-stage deep-frying treatment or this. If microwave dielectric heating is continued, preferably while immersed in oil, the vacuoles in the internal tissue are uniform, the texture is fine, and the degree of swelling is suppressed and adjusted within an appropriate range. Furthermore, the addition of okara and/or concentrated denatured soybean protein does not impair the quality of the final puffed product in terms of flavor, color, etc.

Furthermore, the method of the present invention, which uses okara, which is currently of extremely limited use in food products, has important significance from the standpoint of effective use of resources. Example 1 Whole soybeans were soaked in water for 1 hour, then ground with water using a grinder, centrifuged to separate raw soy milk and okara, and the raw soy milk was heated to a soy milk temperature of 50 to 50°C using a vacuum concentrator. Concentrated soybean milk is prepared by keeping the temperature at 55°C, then sterilized at 70°C for 2 to 3 seconds in a continuous heat exchanger, and then spray-dried with hot air at 120°C to obtain dried soymilk.

This dried soy milk 56.3 parts (moisture 5.0%) and water 36.5 parts
In addition, 91 parts of okara paste with a water content of 75% was added, which was obtained by pulverizing commercially available okara in a roll mill and vacuum-drying it so that the amount passing through a 200-mesh sieve according to the Ryumoto Industrial Standards was 80%. Kneaded for 30 minutes using a twin-screw mixer, the kneaded product had a thickness of 57 TL. Form into a square with each side 40mIm.

Covering the upper and lower surfaces of the formed dough with vinyl sheets to prevent the dough from drying out, leave it at room temperature for 1 hour to measure the affinity between water and protein, then apply palm oil to the surface of the formed dough and place it in a home microwave oven. (output 600W) for 2 minutes in 6 enclosures, then immediately removed from the dielectric heating device and heated to 150°C.
The product was fried for 3 minutes in oil to obtain a product with uniform vacuoles in the internal structure and excellent flavor and color. The degree of swelling of this product was 4.3. Example 2 46.8 parts of water was added to 56" parts of dried soymilk in Example 1,
Furthermore, commercially available concentrated denatured soybean protein (moisture 2.0%, protein content 71.6%, and 95% of protein is insoluble in water) was added to 6. A thickness of 5Tn17Tt. 1
It was formed into a square with sides of 40 TL and 1 m, the top and bottom surfaces were covered with vinyl sheets, and left to stand at room temperature of about 20°C for 1 hour, then taken out, the surface was coated with 0.5y of salad oil, and after 6 years of microwave dielectric heating treatment, it was heated to 150°C. The product was fried in palm oil for 3 minutes to obtain a product with uniform internal tissue vacuoles and excellent flavor and color.

Example 3 7.8 parts of palm oil, 10.7 parts of raw whole eggs, and 48.7 parts of water were added to 17.6 parts of commercially available isolated soy protein (moisture 4.0%), and the okara prepared in Example 1 was further prepared. 8.1 parts of the paste and 5.1 parts of the concentrated modified soybean protein from Example 2 were added and formed into a disk shape with a thickness of 5ml and a diameter of 457T1.1m in the same manner as in Example 1. Cover the bottom surface with a vinyl sheet 3
After leaving it for a while, take it out and apply palm oil to the surface.45
After being subjected to microwave dielectric heat treatment for 2 seconds, the product was fried in palm oil at 160°C for 2 minutes to obtain a product with uniform vacuoles in the internal structure and excellent flavor and color.

The degree of swelling of this product was 3.9.

Example 4 A product with a thickness of 5 m and an I7T1. Formed into a square with sides of 40 TrL and Im, covered with a vinyl sheet and left at room temperature of about 20°C, then immersed in palm oil heated to 140°C and microwaved for (a) seconds. After dielectric heating, the upper and lower surfaces of the dough, which had swelled and floated on top of the oil, were turned over and microwave dielectric heating was continued for another 2 hours. As a result, partial dehydration and surface hardening occurred to the extent that the next frying process was not necessary. As the process progressed, a product was obtained in which the vacuoles inside the tissue were uniformly aligned and had excellent flavor and color.

The degree of swelling of this product was 4.5.

Claims (1)

[Scope of Claims] 1 The main raw material is a soybean protein material having thermocoagulability, to which concentrated denatured soybean protein or okara and concentrated denatured soybean protein, and other edible auxiliary materials are added as necessary. The molded product is kneaded and then molded, and the molded product is heated by microwave induction while being immersed in oil or fat or the surface of the molded product is coated with oil, and then subjected to one stage of deep-frying treatment using a known method. A method for producing foods for deep-frying. 2 The main raw material is a soybean protein substance that has thermocoagulability, and the mixture is kneaded and shaped after kneading with the addition of okara, concentrated denatured soybean protein, or okara and concentrated denatured soybean protein, and other edible auxiliary materials as necessary. . A method for producing a fried tofu-like food product, which comprises subjecting the molded product to microwave dielectric heating while immersed in oil and fat, and continuing the dielectric heating to perform partial dehydration and surface hardening. 3. In the manufacturing method according to claim 1 or 2, 4 to 22% by weight of okara and concentrated denatured soybean protein are added in terms of solid content based on the solid content of the heat-coagulable soybean protein material. 11
A method for producing a fried tofu-like food, which comprises adding okara and concentrated soybean protein at a ratio of 4 to 67% by weight. 4. The manufacturing method according to claim 1, 2 or 3, characterized in that the okara is added after being crushed to an amount of 38% or more that passes through a 200 mesh sieve according to the Japanese Industrial Standards. A method for producing fried tofu-like foods. 5. A fried tofu-like food, characterized in that, in the manufacturing method described in claim 4, okara is added after being crushed to an amount of 80% or more passing through a 200 mesh sieve according to the Japanese Industrial Standards. Manufacturing method.