JPS604702B2 - Dry separation method of soybean protein - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dry separation of proteins, and its object is to obtain a high-protein fraction from defatted soybeans in a good yield by a dry operation method.

Defatted soybeans have a high protein content of 45 to 50% and are widely used in feed and food, but with the recent spread of processed foods, soybean flour with a particularly high protein content is desired for use as a raw material. ing. Currently, a wet method is used to obtain high-protein soybean flour from defatted soybeans, but recently problems have been raised in terms of pollution caused during wastewater treatment.
In other words, protein separation using a wet method not only requires complicated operations such as water or alkali extraction from defatted soybeans, concentration of the extract, and drying, but also that the waste liquid causes environmental pollution in rivers and other areas. have a disadvantage. On the other hand, although attempts have been made to obtain soybean protein by a dry method, commercial satisfaction has not been reached, and there is no alternative method to the wet method.

The conventional dry method for soybean protein is GE. lnge
“S mposlmm: SeedPm-tei” by Mr. tt
ns” (1972 King edition), page 239,
Defatted soybeans with a protein content of 55.5% are 200 mesh (74
The protein content is 59.3% after being crushed and classified to 59.3% (micron) or less.
The yield of only about 8% is obtained. For this reason, it was thought that it would be difficult to obtain a high protein content from defatted soybeans by a dry method commercially. As a result of extensive research into the degree of pulverization and the relationship between the particle size and protein content of defatted soybeans to be separated, the present inventors found that defatted soybeans were pulverized to a certain particle size, and then selected by wind selection into relatively small particles. It has been found that by separating the fleas, a product with high protein content can be obtained in good yield.

Describing the method of the present invention in detail, first of all, defatted soybeans are ground to an average particle size of 5 to 20 microns.

If the degree of pulverization is too large than the above range, the protein-rich portion will not be separated sufficiently, while if it is smaller than the above range, the protein-rich portion and the non-protein-enriched portion will be excessively mixed, making it difficult to perform subsequent classification work. cause trouble. The crushing means used should be those that do not generate heat in the objects to be crushed, and for this purpose an impact crusher is used. Specific examples include impact mills such as hammer mills, ball mills, and rotary plate mills. The pulverizing conditions when using these pulverizers vary depending on the model, but preferably a peripheral speed of 40 to 150 m/sec and a pulverizing time of several seconds. The finely ground defatted soybeans thus obtained are classified.

When defatted soybeans containing soybean seed coats are used as raw materials, it is preferable to use a sieve of 80 to 170 mesh to divide and remove large particle diameter portions in advance for subsequent operations prior to classification. The device used for classification is preferably a dry air classifier, examples of which include a free-vortex air classifier and a forced air classifier.

Classification is carried out using these devices to separate fractions of 15 microns or less, preferably 5 to 10 microns.

The fraction thus obtained has a high protein content and yield, and is extremely easy to obtain. This high-protein defatted soybean has a variety of uses, and is particularly expected to be used as a food material for hamburgers and other foods. Example 1 Defatted soybean (NS188 protein content 49.1%) 3k9 was mixed with Coloplex 25 eave type (
It was supplied to a West German Alpine pin mill (processing capacity 3k9/hr) and processed at 1063 small pm (peripheral speed 140/sec).

Finely ground defatted soybeans (average particle size 13 microns) are used as Mu
When the mixture was classified using ltiplexlo OMZR model (Seidokusan Pine Co., Ltd.) and a 5 to 10 micron fraction was collected, it was found that both protein content and yield were high.

The results obtained by this treatment are shown in the table. (Primary treatment) (Re-processing of the 0 to 10 parts) As is clear from the above data, according to the method of the present invention, the 2 parts with approximately 10% increased protein content compared to the raw material are
It could be obtained with a high yield of 4.4%.

Example 2 Defatted soybeans (NS18 & protein content 49.1%) 2k9 were supplied to a Nara type Meyu crusher M2 type (manufactured by Nara Kikai Seisakusho) (screen opening 2 side, processing capacity 2k9/hour).
Grinding was carried out at 0 specific pm (peripheral speed 50 per second).

Claims (1)

[Claims] 1. A dry separation method for soybean protein, which comprises finely pulverizing defatted soybeans into particles of 5 to 20 microns, and separating the particles having a particle size of 15 microns or less by air selection.