JP3387423B2 - Method for producing soy protein with excellent flavor and gel properties - Google Patents

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 soybean protein having a good flavor and excellent gel properties.

[0002]

2. Description of the Related Art Generally, in the case of hydration of polymers, the hydration rate is slow in the temperature range of room temperature or slightly higher than room temperature, as seen in the hydration of polysaccharides or gelatin. Are known. Soy protein is also a high polymer, and it usually takes time to hydrate and neutralize. The soybean protein neutralization solution is prepared by adding an alkaline solution to the acidic aggregate (curd). At that time, the soybean protein in the curd is insolubilized, and it is considered that the addition of alkali causes the soybean protein to be hydrated and dissolved, and the pH gradually decreases to neutral. In this operation, soybean protein is denatured and insolubilized when heated to accelerate hydration, so high temperature treatment must be avoided. It was necessary to perform hydration / neutralization at a temperature below the denaturation temperature of soybean protein for a long time.

According to the knowledge of the present inventors, it is considered that the following disadvantages occur due to the time required for neutralization as described above. That is, it is the deterioration of flavor due to the growth and oxidation of bacteria. Many fungi are soil fungi that adhere to soybeans, which are the raw material, and are kept low during the process, but they tend to increase during the neutralization process. Regarding the oxidation, the residual lipids present in the neutralized solution are mixed with air by stirring, and are further oxidized, which tends to promote the production of bad taste. From this, it was considered that the deterioration of flavor could be prevented by shortening the neutralization time. In fact, shortening the neutralization time improves them. However, when the hydration of the protein is insufficient, the solubility of the neutralization solution becomes low, and the gel properties of the isolated soybean protein prepared with the neutralization solution remarkably deteriorates.

However, as a result of various investigations, the present inventors have found that after curd is preliminarily stirred into a curd slurry, a high energy treatment is carried out all at once while pouring an alkaline solution in an amount required for neutralization in a sealed manner. It was found that it is possible to instantaneously and continuously prepare a neutralizing solution having high solubility. The inventors have reached the present invention by discovering that neutralization at a high concentration, which seems to be more difficult, can be performed for a short time.

The present inventors have also found that by degassing the curd slurry in advance during the treatment, the flavor and gel strength are further improved.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing soybean protein excellent in flavor and gel properties by efficiently hydrating, neutralizing and heat sterilizing soybean protein curd. is there.

[0007]

[Means for Solving the Problems] As described above, the present inventors suddenly injected a quantity of alkali required for neutralization into a curd slurry prepared by pre-stirring an acidic aggregate of soybean protein in a sealed manner while High energy treatment is performed to continuously complete hydration and neutralization of soybean protein in a short time. Furthermore, the soybean protein production method is characterized in that the neutralized solution is immediately sterilized by heating and then spray-dried.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The acidic aggregate of soybean protein referred to in the present invention may be any form as long as soybean protein is aggregated and precipitated by the addition of an acid, and specifically, an aqueous extract of soybean protein is used. From the acid-precipitated soybean protein by removing the whey fraction from acid-precipitated soybean protein by adding an acid to soybean or defatted soybean.

Further, unless the "high energy treatment at once" according to the present invention, hydration / neutralization of soybean protein is insufficient even with a short-time neutralization treatment, and soybean prepared by spray drying after heat sterilization is prepared. It adversely affects the gel properties of proteins.

The high-energy treatment to be used may be a strong stirring device in a line, ultrasonic treatment, a high-speed circulation device, etc., but the most suitable is a high-pressure homogenizer. This pressure is 50 kg / cm 2 or more, preferably 1
The target neutralization liquid can be prepared by making one pass at a pressure of 50 kg / cm 2 or more. Further, in-line high-speed agitator treatment can be performed in one pass.

In the present invention, the target degree of hydration / neutralization is determined by the protein solubility described below. That is, solid content of neutralization solution 10% by weight, soybean protein concentration 9% by weight
Adjust the concentration of the neutralizing solution to 10,000 G, centrifuge for 10 minutes,
The value obtained by converting the ratio of the weight of the liquid that did not precipitate to the total weight into% was taken as the solubility. The solubility of the neutralization solution was determined on that scale, and the relationship between the gel properties of the powdery soybean protein powder separated by spray sterilization (130 ° C, 15 seconds) and spray drying and the solubility of the neutralization solution was determined. When the solubility of the Japanese solution exceeds 80, the gel value remarkably improves, and when the solubility exceeds 90, the gel value further improves. With a normal stirrer (in-line homomixer), the solubility of the neutralization solution was 71 and the gel value was extremely low, 30 when one pass was performed without repeating. On the other hand, when the in-line high-speed stirrer (Ebara Corporation, "Milder") is installed in the line and the solubility of the neutralizing solution is 88 when processed in 1 pass, it is processed in 1 pass with a high pressure homogenizer (150 kg / cm2). In that case, the neutralization solution had a solubility of 95.

In particular, by performing hydration / neutralization with an in-line high-speed stirrer and a high-pressure homogenizer for a short time in a sealed state, even if the time from card preparation to neutralization, sterilization, and drying is greatly shortened, gel A high-value neutralizing solution can be prepared. Further, by degassing the curd and continuously performing hydration / neutralization treatment in the line, that is, under closed condition, the oxygen concentration during the neutralization treatment can be suppressed. As a result, it is possible to prepare a neutralizing liquid with a good taste in which the growth of bacteria is suppressed and the enzymatic oxidation is suppressed.

The pH of the neutralized solution treated as described above is preferably 6.5 or more, more preferably 7.0 or more neutral to slightly alkaline, but can be adjusted according to the purpose.

Furthermore, by heating and sterilizing immediately after hydration / neutralization and spray-drying, oxidation in the process can be suppressed, and soybean protein having a good flavor can be obtained.

[0015]

EXAMPLES Hereinafter, the embodiments of the present invention will be specifically described with reference to Examples, but the technical scope of the present invention is not limited by these.

Example 1 Low-denaturation defatted soybean flakes (NSI 9 manufactured by Fuji Oil Co., Ltd.)
0) Add 15N of 40 ℃ warm water to 10kg and add 1N Na
The pH was adjusted to 7.5 with an OH solution. This was stirred and extracted for 3 hours, and then the okara component was removed by a centrifuge to obtain defatted soymilk. To this, 1N hydrochloric acid was added to adjust the pH to 4.5, the soybean protein component was precipitated, collected by a centrifuge, and separated soybean protein curd (hereinafter referred to as "curd").
Got The solid content of this curd was about 40% by weight, and the crude protein purity in this solid content was 95% by weight.

Water is added to the curd and preliminarily stirred to obtain a solid content of 1
A 5 wt% curd slurry was prepared. Calculate the amount of alkali needed for neutralization in this curd slurry, and add 1N NaOH
The solution was sent to a high-pressure homogenizer while continuously injecting it closed (without touching air). The pressure of the high-pressure homogenizer was 150 kg / cm @ 2 and one pass treatment was performed. Immediately heat sterilize this neutralized solution (130 ° C, 15 seconds)
And spray-dried to obtain powdery soybean protein isolate.

[0018]

Example 2 The curd slurry prepared in the same manner as in Example 1 was fed to an in-line high-speed stirrer (“Milder” manufactured by EBARA CORPORATION) while continuously injecting an alkali in a sealed manner in the same manner as in Example 1. One pass processing was performed. This neutralized solution was immediately sterilized by heating (130 ° C., 15 seconds) and spray-dried to obtain powdered soybean protein isolate.

[0019]

Example 3 The curd slurry prepared in the same manner as in Example 1 was put into a deaerator and deaerated. This degassed card slurry was fed to a high-pressure homogenizer while continuously injecting an alkali in a sealed manner in the same manner as in Example 1 to perform a one-pass treatment. Immediately heat sterilize this neutralized solution (130
(15 ° C., 15 seconds) and spray-dried to obtain powdery soybean protein isolate.

[0020]

Comparative Example 1 A curd slurry prepared in the same manner as in Example 1 was placed in a tank, and after adding an alkali amount required for neutralization,
By circulating the liquid from the bottom surface of the tank to the liquid surface with an in-line homomixer, hydration and neutralization were gradually performed, and neutralization was performed over 2 hours. Heat sterilize this (130 ℃, 15 seconds)
And spray-dried to obtain powdery soybean protein isolate.

[0021]

Comparative Example 2 A curd slurry prepared in the same manner as in Example 1 was circulated for 20 minutes after adding an alkali in the same manner as in Comparative Example 1, and the neutralized solution was further fed to a high pressure homogenizer. High pressure homogenizer pressure is 150kg / c
One pass treatment was performed at m2. Heat sterilize this solution (130
(15 ° C., 15 seconds) and spray-dried to obtain powdery soybean protein isolate.

[0022]

[Comparative Example 3] The curd slurry prepared in the same manner as in Example 1 was fed to an in-line homomixer while continuously injecting an alkali in a sealed manner in the same manner as in Example 1 to perform one-pass treatment. Immediately heat sterilize this neutralized solution (130 ° C,
15 seconds) and spray-dried to obtain a powdery soybean protein isolate.

Sensory evaluation of various prepared powdery soybean proteins (5% solution) in flavor and solubility, gel value (20% solution was 9%).
After heating at 0 ° C. for 20 minutes, measurement with a card meter) is shown in the table below. Regarding the sensory evaluation of flavor, the larger the score, the better the flavor, and the average value of 24 panelists. −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Solubility / Gel value Machinery Evaluation ----------------------------------------- Example 1 × ○ High pressure homo 95 80 6.2 Example 2 × ○ High-speed stirrer 88 75 6.0 Example 3 ○○ High-pressure homo 95 2 82 7.5 Comparative example 1 ×× in-line mixer 92 80 3.0 Comparative example 2 ×× in-line mixer + high-pressure homo 95 80 4. 6 Comparative Example 3 × ○ In-line Mixer 71 30 5.8 ---------------------------------------------------------------------------------------------------------------------------------------------------

As shown here, the flavor is good if it is neutralized continuously in a short time under sealing. It is even better to degas with a card. In addition, even if a high-pressure homogenizer treatment is carried out, the one which is hydrated and neutralized in an open system for several tens of minutes at the time of neutralization does not have a good flavor (Comparative Example 2). The physical properties of the gel are preferably those treated with a high pressure homogenizer, treated with an in-line high speed stirrer and neutralized for a long time. Therefore, in order to obtain a soybean protein having a good flavor and excellent gel properties, it is effective to prepare a neutralized liquid by high pressure homogenizer treatment with high stirring ability in a short time under sealing, in-line high speed agitator treatment. I understand.

[0025]

As described above, according to the present invention, a soybean protein having a good taste and excellent gel properties can be prepared, and when the neutralizer is a high pressure homogenizer or an in-line high speed stirrer, a high concentration of neutralization is obtained. There is an advantage that the liquid can be continuously prepared in a short time.

Front page continuation (72) Keiko Yamase, 1 Sumiyoshi-cho, Izumisano-shi, Osaka Prefecture Fuji Oil Co., Ltd. Hannan Works (72) Inventor Norio Sawamura, 1 Sumiyoshi-cho, Izumisano City, Osaka Fuji Oil Co., Ltd. Hannan Works (72) Inventor Tomohiko Adachi 2-18-24 Hamanaka-cho, Hyogo-ku, Kobe-shi, Hyogo Fuji Oil Co., Ltd. Kobe factory (56) Reference JP-A-53-62850 (JP, A) JP-B-55- 23058 (JP, B1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A23J 1/14-3/16

Claims (4)

(57) [Claims] 1. A soy protein curd slurry is subjected to a high-energy treatment at a stretch while pouring an amount of alkali required for neutralization in a sealed manner, and continuously soaking the soy protein in a short time.
Neutralization is completed, and the neutralized solution is immediately sterilized by heating.
A method for producing soybean protein, which comprises spray drying. 2. The method according to claim 1, wherein the high energy treatment for neutralization is a high pressure homogenizer treatment. 3. The production method according to claim 1, wherein the high energy treatment for neutralization is an in-line high speed agitator treatment. 4. The method according to claim 2, wherein the acidic aggregate (curd) before the neutralization treatment is degassed.