Preparation method for low-phytic acid calcium-tolerant soybean protein

Abstract

The invention discloses a preparation method for low-phytic acid calcium-tolerant soybean protein. The method comprises the following steps of dissolving low-temperature defatted soybean flour into water, and processing low-temperature defatted soybean flour milk for more than 2 h by phytase to obtain soybean flour milk which is preliminarily processed; performing jet cooking on the soybean flour milk, regulating the pH value to be between 7.5 and 8.5, centrifugally separating, regulating the pH value of supernatant fluid to be between 4.0 and 4.5, dissolving precipitation again with water after centrifuging, and regulating the pH value to be between 6.5 and 7.5; filtering obtained protein solution by an ultrafiltration membrane of which the molecular weight cutoff is 80 kDa, performing spray drying or freeze drying on concentrated solution, and thus obtaining the low-phytic acid calcium-tolerant soybean protein powder. A production process of the low-phytic acid calcium-tolerant soybean protein is low in production cost, the content of the phytic acid reaches 0.12 percent, and the calcium tolerance amount of the protein is 1.0 percent of the weight of the protein. The low-phytic acid calcium-tolerant soybean protein served as a substitute of sodium caseinate can be applied to child and adolescent nourishments, calcium supplement food and medical and clinical nourishments.

Description

technical field [0001] The invention belongs to the technical field of food processing, and relates to a preparation method of functional soybean protein with low phytic acid content and good calcium tolerance and an application example of the soybean protein. Background technique [0002] Soy protein is a high-quality vegetable protein comparable to animal protein, and it is a healthy food raw material with a wide range of sources. At present, domestic soybean protein deep-processing products mainly include soybean protein isolate (SPI) and soybean protein concentrate (SPC). Soybean contains high phytate, the content is as high as 17.9mg / g (dry weight). When soy protein isolate is used in the production of dairy products, the content of phytic acid is too high, which will not only directly affect the solubility characteristics, but also reduce the The calcium content in dairy products also largely affects the body's absorption of nutritional elements such as Ca, Mg, Zn, Cu...

AI Technical Summary

Problems solved by technology

Most calcium supplement products currently on the market are derived from milk. However, due to the sensitivity of soybean protein to metal ions such as calcium, adding soybean protein to foods rich in minerals (especially alkali metal elements) tends to aggregate and form Flocculation and precipitation affect the quality of food, thus limiting the application of soybean protein in soy milk, special functional products such as medical clinical nutrition, liquid food, etc.

[0003] At present, phytase treatment is used alone in the industry to remove phytic acid, but the removed phytic acid and other small molecules cannot be completely dialyzed and exist in the solution in free form, which still affects the calcium resistance of the protein and the functional properties of the protein itself. , the effect is not very significant

When the ultrafiltration membrane molecular interception is large, the protein retention rate is greatly reduced, which affects the protein extraction rate. When the ultrafiltration membrane molecular interception is low, the membrane fouling is very serious, causing difficulties for industrial production.

From the perspective of calcium, using molecular calcium (such as calcium carbonate, calcium phosphate, etc.) or embedding calcium can reduce the contact between calcium and protein to a certain extent to avoid precipitation, but these methods are not conducive to calcium absorption.

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