不同来源蛋白酶水解对大豆分离蛋白分散性及溶解性的影响

研究了动物(胰蛋白酶)、植物(木瓜蛋白酶与菠萝蛋白酶)、微生物(碱性蛋白酶和中性蛋白酶)三种来源蛋白酶的低限度水解对大豆分离蛋白(SPI)分散性和溶解性的影响。结果表明,三种来源蛋白酶轻度水解可显著提高SPI的分散性,但却使其溶解性有不同程度的降低。三种来源蛋白酶水解产物的分散度大小依次为:植物来源蛋白酶>微生物来源蛋白酶>动物来源蛋白酶,而其溶解性则相反:动物来源蛋白酶>微生物来源蛋白酶>植物来源蛋白酶。本文对采用酶解的方法制备高分散性与高溶解性SPI具有一定的参考价值。通过对木瓜蛋白酶水解沉淀物进行分析,可以推测酶解使SPI溶解度显著下降的原因可能是SPI被水解后通过疏水作用力和氢键相互聚集形成了不溶性的沉淀。

Effect of hydrolysis by various proteases on the dispersibility and solubility of soy protein isolate

Soy protein isolate(SPI)was slightly hydrolyzed by animal protease(pancreatin),plant proteases(papain &bromelin)and microbe-proteases(alcalase&neutral proteinase)respectively,and the effect of hydrolysis on the dispersibility and solubility of SPI was systematically investigated.The results showed that the slight hydrolysis could improve the dispersibility obviously,while decrease the solubility significantly.As for the dispersibility,the three kinds of enzymes could be ranked according to the arrangement from high to low as follow:plant proteases >microbe-proteases>animal protease;and as for the solubility,the order was reversed.This study would have some reference value for preparing SPI with high dispersibility and solubility through enzymolysis.The results from the solubility of the insoluble fractions caused by papain hydrolyzation in the different solvents suggested that the hydrophobic area in the soy protein was exposed and promoted the forming of the precipitation.