Alcalase蛋白酶酶解高温豆粕制备水溶性大豆多肽

以氮溶指数为指标,应用Alcalase蛋白酶酶促降解高温豆粕,以获得高得率的水溶性大豆肽。酶促降解的优化实验结果表明:在加酶量1750U/g、底物浓度4%(w/w)、温度60℃、pH9.0的条件下酶促降解3h所得到的水解产物其氮溶指数达到了62.97%,比水解前提高了47.87%;酶解前后大豆蛋白的SDS-PAGE图谱表明:Alcalase蛋白酶可以催化大豆蛋白迅速地降解,水解1h后,7S蛋白的α-亚基,α’-亚基,β-亚基以及11S的酸性亚基已经完全消失,水解3h后,11S的碱性亚基也基本消失,且大多数的肽类分子量在20ku以下;与以大豆分离蛋白为原料制备的多肽相比,以高温豆粕为原料制备的多肽苦味值较低。

Preparation of water soluble peptides hydrolyzing high-temperature soybean meal by Acalase protease

Alcalase protease was used to hydrolyze the high-temperature soybean meal to improve the nitrogen solubility index(NSI).The optimum conditions of enzymatic hydrolysis were as follows:Enzyme quantity 1750U/g,substrate concentration 4%(w/w),temperature 60℃,pH9.0,and time 3h.Under the optimum conditions,the NSI value was 62.97% which was higher than before hydrolysis(47.87%).SDS-PAGE analysis showed that Alcalase protease could quickly hydrolyze soy protein.The α subunit,α’ subunit and β subunit of 7S and acidic subunits of 11S were completely degraded after hydrolysis of 1h.After 3h,basic subunits of 11S disappeared and the molecular weight of the peptides were almost under 20ku.Compared with SPI hydrolysate,the bitterness of high temperature hydrolysate was low.