木瓜蛋白酶水解大豆浓缩蛋白及糖基化修饰对水解产物溶解性的影响

Effect of Papain Hydrolysis and Glycosylation on Solubility of Soybean Protein Concentrate

为提高大豆浓缩蛋白(soy protein concentrate,SPC)在等电点处的溶解性,采用木瓜蛋白酶对大豆浓缩蛋白进行酶解,形成可溶性大豆蛋白,然后将其与葡聚糖进行糖基化反应,形成亲水的蛋白质-多糖复合物。结果表明:大豆浓缩蛋白酶解最佳条件为大豆蛋白与水质量配比5:100、酶添加量10000U/g、反应温度55～60℃;糖基化最佳条件为葡聚糖与蛋白配比1:1、反应时间3.5h;大豆浓缩蛋白在等电点附近(pH4)的氮溶指数由原来的9.53%提高到39.12%。本实验制备的等电点可溶大豆蛋白,可增加其在中等酸度食品中的应用。

In order to increase the solubility of soybean protein concentrate（SPC） at the isoelectric point,SPC was hydrolyzed by papain to form soluble protein and then glycosylated with dextran to form a hydrophilic protein-polysaccharide complex.The best hydrolysis conditions of SPC were determined as follows： SPC concentration 5%,papain concentration 10000 U/g,and temperature 55-60 ℃.The best glycosylation was achieved after 3.5 h of reaction at a dextran/SPC ratio 1：1.As a result,the nitrogen solubility index of SPC near the isoelectric point increased from 9.53% to 39.12%.The obtained soybean protein soluble at the isoelectric point can have more applications in moderately acidic foods.