JPH06217730A - Production of cooked frozen food using bean curd as ingredient - Google Patents

Abstract

PURPOSE:To obtain a method for producing a cooked and frozen food, capable of maintaining the palatability and flavor of raw bean curd and containing bean curd as an ingredient without causing freezing denaturation of the bean curd even after preserving for a long period. CONSTITUTION:Gelatin and starch are uniformly premixed in water and the resultant mixture is then added and mixed with soybean milk. A bean curd coagulant is subsequently added to prepare a bean curd, which is suitably cut and mixed with a cooked liquid sauce and subsequently frozen to afford a cooked and frozen food. Both the gelatin and the starch are added in amounts of 0.05-2.0 pts.wt. based on 1 pts.wt. solid content in the soybean milk. The solid content other than solid materials in the liquid sauce is 10-40wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing cooked frozen foods containing tofu as a ingredient, which does not undergo freezing denaturation and whose quality does not deteriorate even after long-term frozen storage.

[0002]

2. Description of the Related Art Tofu is a traditional Japanese food and has recently been reevaluated as a high-protein, low-calorie food that effectively utilizes soybean protein, and is gaining interest from all over the world. Furthermore, tofu is also used as a material for secondary processing such as deep-fried tofu, cancerous food, and frozen tofu, and is a food material with a wide range of applications.

However, tofu contains about 90% water, and has a drawback that it is extremely poor in storability. Therefore, various methods for improving the preservability of tofu have been conventionally researched and developed. As one of them, freezing treatment of tofu has been proposed. But if you freeze the tofu,
Since ice crystals grow in the tofu during the freezing process, the tofu structure becomes layered and becomes a spongy structure during frozen storage, so-called "su" occurs, and it is significantly different from the texture of normal tofu even after thawing. I will end up. Frozen tofu is produced by positively utilizing freezing denaturation such as tofu.

As a method of preventing freezing denaturation of such tofu and maintaining the texture similar to that of raw tofu even after thawing after freezing, addition of foods such as sugars, emulsifiers and natural gums to soy milk or powdered soy milk. A method has been proposed in which a tofu is added to produce a tofu, and the tofu is stored in a frozen state as it is (for example, JP-A-55-153574 and JP-A-54-145247,
JP-A-52-90650).

[0005]

However, the above-mentioned food additives have extremely low solubility in soymilk, and require homogenization treatment after being added to soymilk, or food of tofu before freezing treatment. The feeling and flavor are far from those of conventional tofu, and it is not always a satisfactory technology for practical use. Furthermore, even with such a method, it has not been possible to completely prevent freezing denaturation of tofu.

[0006] Therefore, the conventional freezing method as a method for preserving tofu itself, and further the method for preventing freezing denaturation, are not satisfactory, and are not in practical use at present.

[0007] Therefore, the present inventors tried to prepare a frozen frozen food containing tofu as an ingredient, not to freeze-process only the tofu as it is, but to cook the tofu into mapo tofu or the like and then to freeze-process. It was If the tofu of the ingredient does not undergo freeze denaturation after thawing such cooked frozen food, it is expected that the use of tofu as a cooked food will become popular.

[0008] Therefore, the present invention has been made for the purpose of providing a method for producing a cooked frozen food containing tofu as a ingredient which is free from denaturation after thawing and can maintain a smooth texture.

[0009]

That is, according to the present invention, a method for producing a cooked frozen food containing tofu as a ingredient is gelatin 0.05-2.
Tofu was prepared by uniformly mixing 0 parts by weight and 0.05 to 2.0 parts by weight of starch with water in advance, adding this to soymilk, and further adding and mixing a tofu coagulant to coagulate the tofu. Tofu cut into an appropriate size is mixed with a liquid sauce having a solid content of 10 to 40% by weight other than solid matter and cooked, and then frozen, or a cooked liquid sauce and cut tofu Is mixed and then frozen.

According to the present invention, the tofu contained as an ingredient suppresses the growth of ice crystals in the tofu tissue during long-term frozen storage due to the action of gelatin and starch, and removes the tofu after thawing. As a result, freezing denaturation can be prevented, and a smooth and elastic texture can be maintained. Further, since the tofu is frozen together with the liquid sauce, the tofu is protected by the liquid sauce. As a result, the denaturation of the tofu during frozen storage and the water separation of the tofu during thawing are prevented more effectively.

In carrying out the present invention, first, a mixed suspension of gelatin and starch is added to and mixed with soymilk prepared by a conventional method. In order to prepare a mixed suspension of gelatin and starch, gelatin is swollen in advance with an appropriate amount of water and dissolved by heating with hot water or the like, and the starch dissolved in water is mixed to form a suspension. In the present invention, since the mixed suspension in which gelatin and starch are suspended in advance is mixed with soymilk, the dispersibility is higher than that in the case where gelatin and starch are separately mixed with soymilk, and the mixture is homogeneous in a short time. It can be dissolved in soy milk. By the way, if you mix soymilk with gelatin only,
Since the viscosity of the gelatin solution is high, strong stirring and long time are required to uniformly dissolve it in soymilk, and especially when the soymilk is cold, the temperature lowers before the gelatin is dispersed, resulting in a sol state. . On the other hand, if you mix only soymilk with starch,
When the soymilk is at a high temperature, the starch is rapidly gelatinized, so that the viscosity of the soymilk also rises rapidly, which hinders the subsequent work of mixing the coagulant, and the soymilk coagulates in a state of containing bubbles. Further, when the soybean milk is at a low temperature, the starch itself does not dissolve in the soybean milk and thus precipitates, which does not serve the purpose of adding the starch.

The amount of gelatin and starch added varies slightly depending on the type of gelatin or starch, but the solid content in soymilk is 1%.
Both gelatin and starch are in a ratio relative to parts by weight.
Generally 0.05 to 2.0 parts by weight, preferably 0.1.
~ 1.0 parts by weight. When the amount of gelatin is less than 0.05 parts by weight, the effect of preventing freezing denaturation of tofu does not appear,
On the other hand, when the amount is more than 2.0 parts by weight, the soymilk protein concentration is relatively decreased, and a large amount of gelatin in the tofu is dissolved during heating and thawing after freezing, so that the tofu has no coagulability and the shape of the tofu is lost. Cannot be maintained. If the amount of starch is less than 0.05 parts by weight, the effect of preventing freezing denaturation of tofu will not be exhibited, while if it is more than 2.0 parts by weight, the tofu protein concentration will be relatively reduced and the starch will be Since it is not heated after it is added to soymilk, it does not gelatinize and has no coagulation power, so tofu does not coagulate.

After a mixed suspension of gelatin and starch is added to and mixed with soymilk, a tofu coagulant is further added to coagulate the soymilk to prepare tofu. As the tofu coagulant, conventionally used calcium salts, magnesium salts, glucono delta lactone and the like can be used. The tofu thus obtained is cut into a suitable size and used as a frozen food ingredient.

As the liquid sauce for mixing the tofu, various kinds can be used depending on the kind of food to be cooked, and various compounding materials for these liquid sauces and various cooking methods can be considered. However, the liquid sauce used in the present invention for preventing freezing denaturation of the tofu of the ingredient has a solid content other than the solid material of 10 to 40% by weight, preferably 15 to 30%.
What was made into the weight% is used. The solid content of the liquid sauce is 10
If the content is less than 5% by weight, the amount of water released from the tofu of the ingredients increases during the heating and thawing of cooked frozen foods, and even in the tofu containing the gelatin and starch produced as described above, "su" is generated. turn into. On the other hand, when the solid content of the liquid sauce is more than 40% by weight, the viscosity of the sauce becomes too high and it becomes difficult to mix it with tofu.

In order to prepare a frozen and cooked food product by mixing tofu and a liquid sauce, a liquid sauce in which ingredients other than tofu are appropriately mixed and tofu cut to a desired size may be mixed and then frozen. Alternatively, a liquid sauce in which ingredients other than tofu are appropriately mixed may be cooked in advance, and tofu cut into desired dimensions may be mixed therewith and then frozen. After the mixture of tofu and liquid sauce is put in an appropriate container, it is frozen using a freezer, a contact freezer, air blast, liquid nitrogen or liquefied carbon dioxide. The freezing temperature is -70 ° C to -10 ° C, preferably -50 ° C to -20 ° C,
Rapid freezing is preferred to obtain stable freezing tolerance.

[0016]

The present invention will be described in more detail with reference to the following examples. Example 1 Production of Frozen Mapo Tofu Based on the formulation of Table 1, soymilk (solid content 11.5% by weight, temperature 80 ° C.), gelatin (“gelatin SN”, manufactured by Nitta Gelatin Co., Ltd.) and After mixing starch (potato starch) and stirring until homogeneous, mix and stir the tofu coagulant (glucono delta lactone), pour into a tofu coagulating can, let stand to coagulate, and then cool by exposing to water. In Test Nos. 1 to 3 of Table 1, gelatin was swollen in water, and then dissolved by heating in hot water and mixed with soymilk as a 15% solution. To 1.5
It was mixed with soymilk as a suspension suspended in a double amount of water. Test Nos. 7 to 9 were mixed with soymilk as a homogeneous suspension by mixing a 15% gelatin solution similar to that used in Test Nos. 1 to 3 with a starch suspension similar to that used in Test Nos. 4 to 6. did. In Test No. 10, gelatin and starch were directly mixed as powders with soymilk. Test No. 11 is a control group, and tofu was prepared using soy milk to which neither gelatin nor starch was added.
Cut the tofu prepared with each test number into 15 mm squares,
Used as tofu for mapo tofu.

[0017]

A liquid sauce for mapo tofu was prepared on the basis of the composition table in Table 2. First, onion, grated ginger, and grated garlic were fried with vegetable oil, and then pork was added and fried. Next, seasonings were added, and finally, potato starch dissolved in water was added, and the mixture was stirred well until it thickened. The solid content of this liquid sauce excluding solids such as pork, ginger and garlic was 22.5% by weight.

[0019]

After cooling the cooked liquid sauce to about room temperature, 100 g of the liquid sauce and the tofu 1 for the mapo tofu 1
00 g was mixed and filled in a container, and quick frozen at -30 ° C for 2 hours, and then stored in a freezer at -15 ° C.
After 30 days and 180 days of storage, the container was taken out from the freezer and heated and thawed, and the texture and flavor of tofu were sensory evaluated. The results of the sensory evaluation are shown in Table 3.

[0021]

As can be seen from Table 3, the tofu (Test Nos. 1 to 3) to which only gelatin was added was unfrozen immediately after production, which was smoother than that of the control group, but was stored frozen for a long time. Due to this, freeze denaturation was unavoidable. On the other hand, the tofu added with only the starch (Test Nos. 4 to 6) was more rough than the one added with the gelatin alone, but the texture was roughened. In addition, when the starch was added to and mixed with soymilk, the viscosity increased remarkably, which hindered the subsequent work of mixing the tofu coagulant and pouring it into a coagulating can.

The tofu (test Nos. 8 and 9) in which a predetermined amount of gelatin and starch were used together as a uniform suspension showed a synergistic effect of the combination, and even after 180 days of frozen storage, the tofu had no freeze denaturation. The appearance and texture were indistinguishable from the unfrozen state immediately after production. No change in flavor, color, viscosity, etc. was observed in the liquid sauce portion. But,
Even when gelatin and starch are used together as a uniform suspension,
When the amount of gelatin and starch was less than the predetermined amount (Test No. 7), the effect of preventing freezing denaturation of tofu was not observed.

Even when gelatin and starch are used in combination, the one in which gelatin and starch are added to soymilk as powder (Test No. 10) causes both gelatin and starch to be lumpy and cannot be uniformly dispersed in soymilk. It became possible, and it was not possible to obtain homogeneous tofu.

Example 2 Effect of Solid Content of Liquid Sauce Using Mabo tofu as an example, the effect of the solid content of the liquid sauce mixed with tofu on the freeze denaturation of tofu was tested.
The tofu used was the tofu obtained in Test No. 8 of Example 1. The material and cooking method of the liquid sauce for mapo tofu are the same as in Example 1 and Table 2, but the amount of potato starch and the amount of melted water used to give a thickening are shown in Table 4, Test No. 12 to.
The solid content of the liquid sauce was adjusted by changing as in 14.
The test No. 15 in Table 4 is a control group, the tofu used was the tofu obtained in Test No. 11 of Example 1 (without addition of gelatin and starch), and the liquid sauce was the liquid sauce of Test No. 14 (solid). The one with the highest amount) was used.

100 g of liquid sauce and 100 g of tofu were mixed and filled in a container, which was rapidly frozen at -30 ° C for 2 hours and then stored in a freezer at -15 ° C. After 30 days, 60 days and 180 days of storage, the container was taken out from the freezer and heated and thawed, and the texture and flavor of tofu were sensory evaluated. The results of the sensory evaluation are shown in Table 5.

[0027]

[0028]

As can be seen from Table 5, in Test Nos. 13 and 14 in which the liquid sauce had a predetermined solid content, the freezing denaturation of tofu was suppressed, and the quality immediately after production was maintained even after frozen storage. On the other hand, in Test No. 12 in which the solid content of the liquid sauce was less than 10% by weight, the effect of suppressing freezing denaturation of tofu was not recognized.

Example 3 : Gratin containing tofu The tofu used was the tofu obtained in Test No. 8 of Example 1. The liquid sauce for gratin was prepared based on the recipe of Table 6. First, onion, carrot and celery were fried with butter.
Separately, wheat flour was fried with butter, brandy, liquid soup, and milk were added and boiled, and the fried vegetables were mixed to prepare a liquid sauce for gratin. The solid content of this liquid sauce excluding vegetables was 25.2% by weight.

[0031]

100 g of this liquid sauce for gratin and 100 g of the above-mentioned tofu were placed in a heat-resistant container and heated in an oven at 220 ° C. for 3 minutes to make the surface brown. This was allowed to cool to room temperature, rapidly frozen at -30 ° C for 2 hours, and then stored in a freezer at -15 ° C. After 30 days and 180 days of storage, the container was taken out from the freezer and heated and thawed, and the texture and flavor of tofu were sensory evaluated.
The results of the sensory evaluation are shown in Table 7.

[0033]

As can be seen from Table 7, no change in texture and flavor of tofu was observed even after 180 days of frozen storage, and the quality immediately after production was maintained. The color, flavor, viscosity, etc. of the gratin sauce other than tofu did not change.

[0035]

As described above, according to the present invention, tofu prepared by adding a predetermined amount of gelatin and starch to soymilk is mixed with a liquid sauce having a predetermined solid content and then frozen. By doing so, there is no stratification of the tofu tissue due to freeze denaturation of tofu during long-term frozen storage, there is no change in texture due to the occurrence of so-called "su" or deterioration of flavor, and a smooth and elastic original tofu original food The feeling and flavor can be retained. Therefore, the method of the present invention can be widely applied to various kinds of cooked frozen foods containing tofu.

Particularly in the present invention, since gelatin and starch are mixed in a state of being suspended in advance in soy milk, the dispersibility in soy milk is higher than that in the case where gelatin and starch are separately mixed in soy milk. It is high and can be homogeneously dissolved in soymilk in a short time. As a result, a homogenizing device is not required, and a conventional tofu manufacturing device can be sufficiently used.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Banba 2-17-8 Mochida, Gyoda-shi, Saitama Asahi Eclipse Products Co., Ltd.

Claims (1)

[Claims] 1. Gelatin 0.05-2.0 parts by weight and starch 0.05-by weight relative to 1 part by weight of solid content in soymilk.
Tofu was prepared by uniformly mixing 2.0 parts by weight of water in advance, adding and mixing this to soymilk, and further adding and mixing a tofu coagulant to coagulate and cut the tofu into an appropriate size. Characterized by mixing with a liquid sauce having a solid content other than solid matter of 10 to 40% by weight and cooking, or by freezing, or by mixing a cooked liquid sauce with cut tofu and then freezing. A method for producing a cooked frozen food using tofu as a ingredient.