JP2502988B2 - Process for producing dried soybean protein with enhanced gel-forming ability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a dried soybean protein having an enhanced gel-forming ability.

<Prior Art> Soy protein has been conventionally used for meat processing, fish paste products, etc., but it itself has a drawback that it has a small gel forming ability. Therefore, studies have been conducted to improve the gel-forming ability, for example, a method of adjusting the pH of soybean protein to the alkaline side, then neutralizing and heating.

<Problems to be Solved by the Invention> However, according to the method described above,
There is a problem that it takes a lot of trouble because pH adjustment and neutralization with an acid have to be performed.

In view of such circumstances, it is an object of the present invention to provide a method for producing dried soybean protein which can improve the gel forming ability of soybean protein powder without much effort.

<Means for Solving Problems> The constitution of the present invention which achieves the above object has a water content of 3 to
It is characterized in that 18% by weight of soybean protein powder is stored at 45 to 150 ° C for a certain period of time.

Soybean protein powder used in the present invention may be, for example, dried soybean protein liquid or paste soybean protein before producing isolated soybean protein powder or concentrated soybean protein, or produced by various other methods, for example, Commercially available soybean protein powder can also be used. An example of a commercially available soy protein powder production method is soybean obtained by defatting soybeans crushed according to a conventional method with hexane and then water-extracting from low-temperature defatting food grade foods with an NSI (nitrogen solubility index) of 80 or more. The protein solution is dried to obtain soybean protein powder, and spray drying, freeze drying and the like are adopted as the drying method. And, in the present invention, the water content of the dried soybean protein powder is 3-18%. This is because if the water content is less than 3%, the gel strength is difficult to be strengthened by the subsequent heat storage step, while if it exceeds 18%, it tends to boil due to heat storage and lose its solubility, and gelation tends to be impossible. .

In the present invention, the gel-forming ability is improved by thus heat-storing soybean protein powder having a water content of 3 to 18% by weight. Here, the term "heat storage" means holding at a predetermined temperature for a certain period of time. For example, if soybean protein powder is contained in a container such as aluminum, glass, or plastic and kept in the heat storage at a predetermined temperature for a certain period of time. Good. Further, when it is desired to shorten the holding period, it may be treated with a continuous heating device such as an extruder.

The holding temperature for this heat storage is 45 to 150 ° C. This is because it is hard to strengthen the ell strength below 45 ° C,
If it exceeds, the soybean powder will be boiled and lose its solubility, and gelation tends to become impossible. The heat storage period is not particularly limited, and may be changed depending on the water content of soy protein powder and the holding temperature. For example, if the water content of soy protein powder is 3% and the holding temperature is 45 ° C, it will take about 14 days.
When the water content of soybean protein powder is 18% and the holding temperature is 150 ° C, it may be 1 to 2 minutes.

In the present invention, the soybean protein powder having a water content of 3 to 18% by weight is thus heat-stored to improve its gel forming ability, but it is not clear why this action occurs. However, by soaking the soybean protein powder having a certain water content for a certain period of time, originally, by stimulating the heat coagulation property of the soybean protein, the heat coagulation property is further enhanced and the gel forming ability is improved. Seem.

Hereinafter, the present invention will be described in more detail with reference to test examples and examples.

〈Test example〉 Test example 1 Separated soybean protein powder with water content adjusted to 2%, 3% and 4%
It heat-stored at 75 degreeC for 2 days. Also, the water content is 17%, 18%, 19
The separated soy protein powder (%) was heated at 105 ° C. for 2 minutes by a rotor type heater.

7 parts by weight of water was added to 1 part by weight of each sample stored in the heat and dissolved. Then, put each in a plastic casing with a diameter of 57 mm, heat at 80 ° C for 60 minutes, and after cooling
It was cut into a thickness of 3 cm, and the gel strength of each was measured with a rheometer. At this time, the planer has a spherical shape of 8 mmφ. The test results are shown in Table 1.

From these results, it was confirmed that the gel strength is enhanced when the one having a water content of 3 to 18% is heated, as compared with the unheated one.

Test Example 2 Separated soybean protein powder having a water content of 15% was used at 40 ° C, 50 ° C and 60 ° C for 10 minutes.
Heated for each minute. Separated soybean protein powder having a water content of 4% was heated at 140 ° C., 150 ° C. and 160 ° C. for 1 minute with a rotor type heater.

The gel strength of each sample was measured in the same manner as in Test Example 1, and the results are shown in Table 2.

As a result, it was confirmed that the gel strength was strengthened when the holding temperature of the heat storage was 45 ℃ ~ 150 ℃ compared to that of the unheated storage.

Test Example 3 Separated soybean protein powder having a water content of 18% at 150 ° C.
It was heated with a rotor type heater for 30, 45 seconds. Samples with the same water content were prepared and stored at 45 ° C for 8, 10 and 12 days, respectively.

The gel strength of each of the obtained samples was measured in the same manner as in Test Example 1, and the results are shown in Table 3.

As a result, it was confirmed that the gel strength was enhanced as compared with the unheated one.

Test Example 4 Soy protein powder that had been stored at room temperature for a long time (one year) and no longer formed a gel was stored at 50 ° C. for 8 days, and the gel strength was measured in the same manner as in Test Example 1. The results are shown in Table 4.

In general, soybean protein powder loses its gel-forming ability when stored at room temperature for a long period of time, but when this soybean protein powder is stored in heat, the gel-forming ability is restored and its gel strength is twice as high as that before storage. Was recognized.

Example 1 An isolated soybean protein powder having a water content of 6% was obtained by spray drying from acid-precipitated soybean protein according to a conventional method. When this soybean protein powder was packed in a polyethylene bag and heat-treated at 65 ° C. for 2 days, dried soybean protein with enhanced gel-forming ability could be obtained.

Example 2 Separated soybean protein powder having a water content of 10% was obtained from acid-precipitated soybean protein according to a conventional method. When this soybean protein powder was heated with a rotor type heater at 120 ° C. for 10 minutes, dried soybean protein with enhanced gel-forming ability could be obtained.

Example 3 A defatted soybean powder having an NSI of 85 defatted with hexane according to a conventional method was extracted with water. This solution was spray-dried to obtain soybean protein powder having a water content of 6%. When this soybean protein powder was heated with a continuous kneader at 150 ° C. for 2 minutes, dried soybean protein with enhanced gel-forming ability could be obtained.

<Effects of the Invention> As described above in detail with reference to Test Examples and Examples, according to the present invention, the gel-forming ability is significantly enhanced by heating soybean protein powder having a certain water content for a certain period of time. Therefore, when the obtained dried soybean protein is used as an auxiliary raw material such as ham and sausage, the effect of gel strengthening is exerted, and a product with smooth and crisp crispness can be obtained.

Claims (1)

(57) [Claims] 1. A soybean protein powder having a water content of 3 to 18% by weight is used.
A method for producing a dried soybean protein with enhanced gel-forming ability, which comprises heat-storage at a temperature of up to 150 ° C for a certain period of time.