Preparation method of soy isolate protein rich in branched chain amino acid

Abstract

The invention discloses a preparation method of a soy isolate protein rich in branched chain amino acid. The preparation method comprises the following steps: preparing the soy isolate protein firstly, stirring uniformly, heating, hydrolyzing with alkaline protease, stabilizing the pH (potential of hydrogen) within an appointed range in the hydrolysis process by using NaOH; inactivating the hydrolysate with boiling water, adjusting the pH value by adding HCl, centrifugally separating, taking supernatant for later use; freeze-drying the hydrolysate by a vacuum freeze-drying machine, and porphyrizing the hydrolysate to be put into the drying machine; adjusting the pH value of the solution, and under the presence of L-cysteine, adding papain to catalyze the reaction, wherein the enzyme adding amount is 2%; after the reaction is finished, depositing protein with ethanol, centrifugally separating, enabling the protein to pass through a dialysis bag, centrifugally separating, and freeze-drying, so as to obtain the final product, namely the precipitate. Compared with the prior art, the branched chain amino acid is introduced into proteins such as soy protein by using a plastein synthesis method, so as to obtain a plastein product rich in branched chain amino acid, the purpose of supplementing the branched chain amino acid can also be achieved after the plastein product is eaten; furthermore, the product is stable in character, preferable in processability, and does not have any bad mouth feel.

Description

technical field [0001] The invention relates to a method for preparing soybean protein isolate, in particular to a method for preparing soybean protein isolate rich in branched-chain amino acids. Background technique [0002] It has been known for a long time that branched-chain amino acids including three kinds of amino acids, namely, extractine, leucine, and isoleucine, have the function of increasing protein, or can play an important role as an energy source during exercise, and various types of amino acids have been developed. Drugs, food and supplements containing branched-chain amino acids were launched and launched. [0003] However, the existing medicines, foods and supplements containing branched-chain amino acids usually prepare free branched-chain amino acids or small peptides containing more branched-chain amino acids into injections, granules or tablets, or add them to food , beverages to obtain products rich in branched chain amino acids. On the one hand, the...

AI Technical Summary

Problems solved by technology

On the one hand, these products have a unique bitter smell derived from branched-chain amino acids. In addition, the stability of free amino acids or small peptides is poor. During storage and sales of products, it is easy to reduce the content of branched-chain amino acids and even change the shape of the product.

At the same time, because branched-chain amino acids are hydrophobic amino acids, for example, granular preparations containing branched-chain amino acids are difficult to be compatible with water. Problems such as a large amount of residue in the mouth

Some researchers have also used enzymatic hydrolysis and separation using specific techniques to prepare small peptides rich in branched-chain amino acids, but these small peptides do not have functional properties such as texturization, and may have a certain bitter taste, which is not conducive to food Industrial application