几种常规改性方法对大豆蛋白化学结构的影响

摘要

The soybean protein was modified by several conventional methods and then the soybean protein’s chemical structure was analyzed by infrared spectrum. The result showed that thermal modification did not change the primary structure of soybean protein, but it made the soy protein thermal denaturation and combined with each other,leading increase of solution viscosity. Enzyme could hydrolyze the peptide or amide bond of the polypeptide chain to some extent, and the intramolecular or intermolecular crosslinking of the peptide chain. Acid-modification partially hydrolyzed peptide bond, but it would not change the peptide chain, and acid could dissociated soybean globulin, causing reduction of viscosity. Alkali could greatly hydrolyze peptide or amide bonds, catalyzing many polar groups crosslinking reaction,which producing greater weighted molecules, and making viscosity of solution increasing sharply.%采用红外光谱分析研究了热改性、酸碱改性和酶改性对大豆蛋白化学结构的影响。结果表明：热改性不会对大豆蛋白的一级结构造成影响，但会使大豆蛋白发生热变性，并发生缔合作用，使溶液粘度升高；酶能在一定程度上水解多肽链上的肽键或酰胺键，且能增加肽链分子内或分子间的交联；酸改性会部分水解肽键，但不会对肽链造成大的影响，并且酸还能解离大豆球蛋白，使溶液粘度大幅降低；碱能大幅度地水解肽键或酰胺键，暴露出大量的极性基团，并且这些基团在碱的催化作用下，发生了交联反应，生成了分子量更大的分子，使得溶液粘度急剧升高。