JPH01148166A - Processed bean curd food - Google Patents

Abstract

PURPOSE:To obtain the title food with a high amino acid content, by reacting bean curd with a proteolytic enzyme and hydrolyzing proteins. CONSTITUTION:Bean curd is produced according to a conventional method and the surface water is adjusted to about 65%. A proteolytic enzyme (e.g., Aspergillus oryzae) is then uniformly sprayed on the surface thereof to carry out cultivation at 28-35 deg.C for 20-35hr to hydrolyze proteins. Common salt is subsequently rubbed into the surface and the resultant bean curd is stored at <=15 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to processed tofu foods, particularly to processed tofu foods with high amino acid content.

Tofu has been served as a very common food for a long time, but it has traditionally been cooked as is, fried, or fried.
It is simply processed into foods such as Koya tofu. Therefore, to date, no attempt has been made to process and denature tofu to produce a food product that has a completely different flavor from the tofu that is the raw material.

The present inventor has now completed the present invention by discovering that a food product with a high free amino acid content and a cheesy flavor can be obtained by treating tofu with a proteolytic enzyme.

Therefore, according to the present invention, a processed tofu food with a high content of amino acids (free amino acids) is provided, which is obtained by decomposing the protein in tofu by allowing a proteolytic enzyme to act on the tofu.

In the following, the method for producing the processed tofu food of the present invention will be explained in detail.

In producing the processed tofu food of the present invention, first,
Tofu is produced from soybeans according to conventional methods. The tofu is then dehydrated during the pressing process during tofu production to reduce the water content to 70% or less to obtain firm tofu. The firm tofu thus obtained is cut (sliced) into layers. In this case, the thickness of the tofu should be adjusted to 4.5 cm, because if the tofu is too thick, the enzymatic decomposition of the protein will not be carried out sufficiently.
It is preferable that the thickness be c11 or less (note that tofu having such a thickness may be manufactured from the beginning).

Therefore, in this process, for example, 10xlOx4 (thickness)
cm, IOX 4 x 1.5 (thickness) cm, or 4 x 4 x 4 (thickness) cII pieces of tofu are produced.

The moisture on the surface of the tofu can be reduced by 65% by absorbing the moisture on the surface of the tofu pieces using a piece of cloth, or by placing them in a high-heat oven at 100 to 150°C for a short time to evaporate the moisture.
% is preferable.

Next, in the present invention, a protease is applied to the dehydrated tofu pieces produced above to decompose the protein in the tofu and generate free amino acids. (a) Using and propagating Aspergillus oryzae, the protein in tofu is degraded by the action of the proteolytic enzyme secreted by Aspergillus oryzae.

(o) Using RM koji powder, proteins are decomposed by the action of the proteolytic enzyme possessed by the koji mold in i.

(c) Use a powder containing protease.

Therefore, the term "proteolytic enzyme" as used herein refers not only to the protease itself or to preparations containing it as a main ingredient, but also to the proteolytic enzymes secreted by Aspergillus oryzae such as those mentioned above, and to the aspergillus Aspergillus oryzae produced during visits to China. It also contains proteolytic enzymes possessed by.

When using koji mold according to the method described in (a),
Aspergillus spores are sprayed uniformly onto the entire surface of the tofu pieces to inoculate them. Next, the tofu pieces inoculated with koji mold were heated to 28-35°C.
The bacteria are cultured for 20 to 35 hours by placing them in a constant temperature bath maintained at a temperature of . The reproduction rate varies depending on the type of koji mold used, so cultivation can take as long as 20 hours for a fast culture or 35 hours for a slow culture.
It takes time.

Commonly used koji molds, namely,
Aspergillus aspergillus of the genus Aspergillus, such as Aspergillus aspergillus (Amazake Aspergillus), Miso Serum.

Oil koji mold]"November↓US 7- etc. can be used. however,
If bacteria with strong proteolytic ability are used, a product with better taste can be obtained.

The pieces of tofu on which the koji mold has sufficiently grown and the protein has been sufficiently decomposed are taken out from the thermostatic bath, the surface is sprinkled with salt to prevent deterioration, and the pieces are stored in a refrigerator at 15° C. or lower. The expiration date after storage is about 3 weeks.

When grain koji is used according to the method of (II) above, koji fine powder obtained by crushing koji produced from grains such as rice and wheat to a diameter of IW or less is used as tofu pieces produced by the above method. The tofu pieces are then wrapped and sealed in a suitable plastic film. Then, the packaged tofu pieces are placed in a thermostatic water bath or thermostatic chamber maintained at a temperature of 50° C. to 65° C. and left for 1 to 4 hours.

Then, it is stored in a refrigerator at 10°C or lower for 2 days or more, and then used for consumption. Mix the koji powder with salt according to your preference,
It is also possible to impart a salty taste to the product.

In addition, when producing the above grain koji, the same koji mold as described above can be used.

Next, when using the protease-containing powder according to the method (c) above, an aqueous solution of the protease preparation (for example, 1 g of the enzyme preparation dissolved in 500 cc of water),
A proteolytic enzyme-containing powder with a water content of 15% or less is prepared by mixing it with grain powder such as rice or wheat or legume powder.

As the above-mentioned grain or legume powder, those that are roasted or dry heat sterilized at a temperature of 100° C. or higher are usually used. Furthermore, as the enzyme preparation, a commercially available enzyme preparation or one prepared by the method described in Example 3 below can be used.

The enzyme-containing powder prepared by the above method is applied and rubbed onto the entire surface of the tofu pieces described above, and the tofu pieces are wrapped and sealed with a plastic film. Thereafter, the packaged tofu pieces are processed in the same manner as in (υ) above. By processing, the processed tofu food of the present invention can be obtained.

The processed tofu food of the present invention obtained by the above method is Product 1
It is a cheese-like food containing more than 1000 amino acids per 00g (dry weight), and as is clear from the examples below, it is very delicious because it has a high content of free amino acids, especially glutamic acid, and can be used as a snack food. It is suitable. In addition to glutamic acid, nutritionally,
Since it contains a large amount of amino acids that are considered essential amino acids, it is an excellent high-vegetable protein food and a so-called health food.

Examples of the present invention are shown below.

Backyard ■ - Tofu was produced according to a conventional method, but firmer tofu was obtained by increasing the pressure in the pressing process (moisture 68.5
%), cut this tofu into 10 cm x 4 cm x
Tofu pieces of 1.5 am were obtained. The pieces of tofu were wrapped in highly absorbent cotton cloth to remove as much water as possible from the surface of the pieces of tofu.

Seed koji of yellow koji mold (Kagoshima type, manufactured by Kawachigen Some Shoten Co., Ltd., Bay koji mold was used) was uniformly sprinkled on the entire surface of the surface-dehydrated tofu pieces obtained above.

After the seed koji inoculation was completed, the tofu pieces were placed in a 30-35°C incubation room (koji room) and koji mold was propagated for about 35 hours.

During this time, the koji mold cells were allowed to extend over the entire surface of the tofu piece, so that the entire surface of the tofu piece was coated with koji mold cells to a thickness of about 0.2 mm.

Next, in order to improve the shelf life of the product, salt in an amount of 5% of the weight of the tofu pieces is rubbed over the entire surface of the tofu pieces on which the koji mold has grown, wrapped in plastic film, and placed in a refrigerator at 12°C or below for preparation. Ripe. From around the third day of ripening, the amino acid content increased, further enhancing the flavor. The shelf life of this product is approximately 30 days after manufacture when stored at 10°C or below. The analytical values of this product after 7 days of ripening are as shown in the ingredient list below.

Implementation test-1 10cm x 4c manufactured by the same method as Example 1
A mixed powder of barley koji powder and common salt prepared by the method described later was uniformly rubbed onto the entire surface of a 5 cm piece of tofu, wrapped in a plastic film, and sealed. The sealed tofu pieces were then immersed in a constant temperature water bath at 55°C and left in the water bath for about 3 hours to undergo enzymatic decomposition.

After being removed from the water tank, the package was stored in a refrigerator at 10°C and aged for 7 days to obtain a cheese-like product. The analytical values of this product are as shown in the ingredient list below.

The mixed powder of barley koji powder and salt used in the above method is made by making barley koji using barley as a raw material in a conventional manner (40-hour koji making), drying this at 60°C or less to a moisture content of about 13%, and then grinding. The obtained dried barley koji was ground into a powder having a diameter of 1 mm or less, and this barley koji powder was mixed with common salt in an amount of 5% of the weight of the powder.

[ Disperse 1 g of the crude enzyme preparation prepared by the method described later in 30 cc of water, dissolve the resulting solution, and add 15 g of fine roasted barley powder.
After mixing with 0 g of sodium chloride and further adding 7.5 g of common salt, the mixture was thoroughly mixed to obtain a protease-containing powder.

This enzyme-containing powder was thoroughly rubbed over the entire surface of a piece of tofu similar to that described in Example 1, and the piece of tofu was then wrapped and sealed in a plastic film. 20 kg of tofu pieces can be treated with 100 g of the above enzyme-containing powder.

The sealed tofu pieces obtained above were immersed in a constant temperature water bath at 55°C, enzymatically decomposed in the bath for 4 hours, and then rapidly cooled. After taking it out from the water tank, it was aged in a refrigerator at 10° C. for 7 days to obtain a cheese-like product of the present invention.

The analytical values of this product are shown in the table below.

The crude enzyme preparation used above was prepared by the following method: 600g of yellow koji made from rice bran as a raw material and 1% salt solution 37%. was added, and the enzyme was extracted at 30°C for 3 hours.

Alcohol was added to this extract to precipitate the crude enzyme, and the precipitated enzyme was air-dried to obtain 42 g of crude enzyme with a water content of 15.5%.

Note that similar results can be obtained when a commercially available enzyme preparation is used instead of the crude enzyme preparation prepared by the above method.

Claims (1)

[Claims] Processed tofu food with high amino acid content, made by decomposing the protein in tofu by allowing proteolytic enzymes to act on tofu.