JPS61192256A - Production of whole grain soya milk for bean curd or food prepared from soya milk - Google Patents

Abstract

PURPOSE:To obtain a whole grain soya milk for bean curd or for a food prepared from soya milk, having improved coagulation property, by grinding soaked soybeans in the presence of water, heating under specific condition, and homogenizing with an ultra-high pressure homogenizer. CONSTITUTION:Raw soybeans (dried soybeans) are soaked with water by immersing in water for 12-18hr, and the soaked beans are added with water to attain a solid soybean content of 7-20%. The beans are ground with a grinder to obtain ground liquid of whole soybean having particle diameter of 0.1-500mu. The liquid is heat-treated at 90-100 deg.C for 10min to reduce the S-S group of the soybean protein to SH group. The objective soya milk can be prepared by homogenizing the treated liquid with an ultra-high pressure homogenizer under 400-1,000kg/cm<2> pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing whole grain soymilk for use in tofu or soymilk-based foods with improved coagulation properties.

Research into foods using soy milk has become particularly active in recent years, and soy milk has come to be used as an ingredient not only in tofu but also in almost all foods.

However, soy milk is usually produced by removing okara, which is a water-insoluble component, from soybeans (whole grains), so the yield is low and it is uneconomical, and it is also difficult to dispose of the okara.

On the other hand, recent nutritional research has shown that dietary fiber and indigestible components, which are the main components of okara, are deeply related to human health through a qualitatively different effect from that of essential nutrients, and are important for the body. Because it has homeostasis maintenance and therapeutic effects, it has been found to be useful in preventing colon cancer, constipation, heart disease, diabetes, gallstones, arteriosclerosis, etc. caused by the current meat-based diet.

Therefore, a method for producing whole grain soy milk (beverage) that contains all the components (whole grains) of soybeans without producing okara (for example,
1052, JP 53-66466) and foods using the same (e.g. JP 57-33021, JP 52-110852) have been published, but conventional whole grain soymilk During the manufacturing process, soybean protein is subjected to excessive denaturation due to long-term heat treatment at high temperatures.
The binding of tofu coagulants such as Ca, Mg salts, or GDL (glucono delta lactone) with proteins (protein-salt bond) is inhibited, resulting in poor curd-forming ability and poor soybean production. In order to incorporate all of the components into soymilk, protein denaturation must be done properly under heating conditions suitable for curd-forming ability, and if sufficient protein-field bonding is not achieved, the grains will be coarse and may have drawbacks such as a poor texture. Ta.

In other words, even if you try to make tofu from whole grain soy milk,
Normal tofu coagulants alone cannot coagulate completely and have poor shape retention, so instead of using the coagulant properties of protein-salt or acid, the coagulant itself is a gelling agent, and the coagulation agent itself is a gelling agent. Some agents gel by themselves, and some do not involve protein.
By adding two arbitrary substances, a coagulation reaction is caused. Therefore, the unique curd texture due to the protein-salt or acid bonds of tofu cannot be obtained, and the curd texture is similar to that of a gelling agent, which is different from tofu in texture and similar in appearance to tofu. In addition, when producing soy milk pudding, soy milk soup, etc., it was not possible to produce products that were smooth and had a good texture.

In view of the fact that it is known that changing the S-8 group in soybean protein to an SH group is effective in improving the coagulability of soymilk, the inventor conducted extensive research on a method for promoting the reaction. As a result, it was discovered that when unheated whole soybean grinding solution was treated at a previously unknown temperature, the SH groups in soymilk increased.In addition, in order to improve the roughness (texture) of whole soybean milk, The present invention was completed by discovering that whole grain soybean milk can be processed using an ultra-high pressure homogenizer, which has not been used in the past.

In other words, this invention (1) raw soybeans (dried soybeans)
$1 process of soaking in water for 2 to 18 hours to absorb water (
2) Add water to the water-absorbed soybeans obtained in the first step so that the soybean solid content is 7 to 20%, and grind with a grinder to obtain a whole soybean grinding liquid with a particle size of 0.1 to 5004. (3) a third step in which the whole soybean grinding solution obtained in the second step is heat-treated at 90 to 1°C for less than 10 minutes;
Step (4) The soybean grinding liquid obtained in the third step is 400 to 1000 Kg/c using an ultra-high pressure homogenizer.
By sequentially passing through the fourth step of homogenizing at a pressure of rn', the S-3 group of the protein in whole grain soymilk is changed to an S)I group, increasing the coagulation ability of soymilk, and improving the coagulation ability of the soymilk. This was developed with the aim of providing a method for producing whole grain soymilk for use in tofu or soymilk-based foods that has sufficient coagulation ability using only a tofu coagulant and is free from graininess.

In this invention, tofu refers to stuffed tofu, firm tofu, silken tofu, fried tofu, etc., and soymilk-based foods include all foods that use soymilk as a raw material, such as soymilk pudding and soymilk soup.

The details of the first to fourth steps according to the present invention are as follows.

First step: This is a step in which raw soybeans (dried soybeans) are soaked in water for 12 to 18 hours. The immersion temperature is usually 5 to 30°C. Since the whole grain soymilk of the present invention is mainly used for producing tofu, there is no need to heat (steam) soybeans to inactivate lipoxidase, trypsin inhibitor, etc. Conversely, if heat treatment is carried out for this purpose, the soybean protein will be denatured outside the range suitable for gel-forming ability, making it impossible to obtain whole soybean milk for producing tofu, which is the object of the present invention. This point is explained in the above-cited Japanese Patent Application Laid-open No. 51-66466 or Japanese Patent Application Laid-open No. 51-6646, which requires heat treatment at high temperature and for a long period of time during soybean grinding or before soybean grinding.
It differs from the soymilk described in Japanese Patent No. 2-110852 in terms of wood quality.

2nd step: Add water to the water-absorbed soybeans obtained in the 1st step so that the soybean solid content is 7-20%, and grind with a grinder to obtain a particle size of 0.1-500%. This is the process of making a whole soybean grinding solution.

3rd step: Whole soybean grinding liquid obtained in the 2nd step
This is a process of heat treatment at 0 to 100°C for less than 10 minutes.

In this invention, the whole soybean grinding solution is heated to 90 to
Complete io minutes at 100°C. In order to coagulate soy milk (whole grain soy milk) by adding only a regular tofu coagulant and obtain tofu with sufficient hardness (80 g/crn'), heat treatment at 80°C for 3 minutes or more is necessary. It is necessary to thermally denature the proteins in soy milk (whole soybean grinding solution) in advance. On the other hand, SH groups in soymilk undergo a decomposition reaction and a formation reaction simultaneously during heat treatment, and their content is 70°
C (3 minutes, same below) decreases from 80℃ to 80℃
It was found that when the temperature gradually increases from C to 98°C and exceeds 100°C, the decomposition reaction is significantly accelerated and the SH group suddenly decreases. Therefore, the above-mentioned 90 to 100 ”0
By heating within 10 minutes, the S-8 group in soybean protein is efficiently reduced to -SH group and remains.
By simply adding a normal tofu coagulant to the whole soybean milk produced through this treatment, it is possible to produce tofu with sufficient hardness. Next, the SH when the whole soybean grinding liquid (solid content 1O12%) was subjected to the above heat treatment.
Changes in the amount of soybeans produced and GDL in whole soymilk treated with this process
Table 1 shows changes in the hardness of filled tofu produced by adding (glucono delta-lactone).

Table 1 In conventional methods for producing whole grain soymilk, the main focus was on softening the soybeans when determining the heating conditions, and no consideration was given to promoting the reaction. The time was high and too long, so it was not possible to produce satisfactory tofu using a normal soy milk coagulant. Therefore, the present invention combines whole grain soymilk with a conventional tofu coagulant (
This made it possible for the first time to produce tofu using only calcium salts, GDL, etc.).

4th step: ・The soybean grinding liquid obtained in the 3rd step is 400 to 1000 Kg /
This is a step of homogenizing at a pressure of crn'.

The ultra-high pressure homogenizer used in this invention has a maximum of 400
Although any type may be used as long as it has a pressure of ~1000 Kg/cm2, the Manton-Gorlin type was mainly used in the testing of the present invention.

The particle size of the whole soybean grinding liquid before being treated with an ultra-high pressure homogenizer should be 500 JL or less, but
If possible, the particle size of whole grain soybean milk is preferably 150 μ or less, and the particle size of whole grain soy milk is usually reduced to 50 μ by processing with an ultra-high pressure homogenizer.
It needs to be less than L.

As mentioned earlier, in order for tofu to form curd through protein-salt bonds or protein-acid bonds (GDL), it is better that the ground soybean particles are finer, and this condition must be met. As a prerequisite, whole soybean milk is heated under conditions suitable for curd formation to promote the above reaction.

Next, we will discuss soybean particle size, gel strength and sensory evaluation when the above reaction is carried out appropriately.

(1) For particle size 15-30, gel strength 125g/
For cm': Fine and silken tofu-like texture.

(2) Particle size is 31-50 pL, gel strength is nog/
In the case of Cm': Random coagulation, somewhat like firm tofu, is felt.

(3) Particle size is 51-100 l, gel strength is 85g/
In the case of cm': The curd has a weak and lumpy texture.

"Example" 100 kg of whole soybean grinding solution (solid content 11.0%) was heat-treated at 98°C for 10 minutes using a tofu boiler, and then 600 kg was processed using a Manton-Gorlin type ultra-high pressure homogenizer.
The mixture was homogenized at a pressure of /cm2 to obtain whole soy milk for tofu or soy milk foods. The SH group content of this whole grain soymilk is 6,8
X10'M/g Protein.

[Example of tofu production]

A coagulant (
GD L: Ca 5O4 = 8: 2) to 0.3
Filled tofu was prepared by adding 6% tofu, sealing the package, and heating at 88°C for 45 minutes. This stuffed tofu has better water retention (less whey-off phenomenon) than regular stuffed tofu.
Hardness is 130g/Cm' (regular stuffed tofu is 90g'
/ crn'), it was hard and rich, with an accentuated sweet bean aroma, and was similar to firm tofu, making it particularly suitable for hotpot cooking.

As described above, according to the method for producing whole soybean milk for tofu or soymilk foods according to the present invention, soybean protein can contain a large amount of SH groups, so that whole soybean milk that can be easily coagulated with a common tofu coagulant is used. Granular soy milk can be obtained.

Therefore, tofu produced using whole grain soymilk as a main ingredient according to the present invention (tofu mixed with ordinary extracted soymilk, etc. in any proportion) has (1) higher hardness than ordinary tofu, and has better shape retention. It also has good water retention properties, making it excellent for cooking hotpots, simmered dishes, etc.
(2) It has more soybean flavor than regular tofu, with a distinct cotton-like flavor; (3) It is economical as all the okara parts are edible, and it also contains a large amount of indigestible ingredients such as soybean fiber. It has many excellent characteristics, such as being useful in preventing adult diseases.

Claims (1)

[Scope of Claims] A method for producing whole grain soymilk for use in tofu or soymilk-based foods, which comprises sequentially carrying out the following first to fourth steps. First step: A step in which raw soybeans (dried soybeans) are soaked in water for 12 to 18 hours to absorb water. 2nd step: Add water to the water-absorbed soybeans obtained in the 1st step so that the soybean solid content is 7-20%, and grind with a grinder to grind whole soybeans with a particle size of 0.1-500μ. Process of making crushed liquid. 3rd step: Whole soybean grinding liquid obtained in the 2nd step
A process of heat treatment at 0 to 100°C for less than 10 minutes. 4th step: The soybean grinding liquid obtained in the 3rd step is 400-1000Kg/cm^2 using an ultra-high pressure homogenizer.
A process of homogenization under pressure.