双酶法制备大豆降胆固醇活性肽的研究

Preparation of Soybean Hypocholesterolemic Peptides by Double-protease Method

通过比较4种酶对大豆分离蛋白的水解效果,并通过单因素及L9(34)正交试验优化其水解工艺条件,研究其最佳水解工具酶及最佳酶解参数。结果表明:木瓜蛋白酶和植物蛋白酶联合应用可作为大豆分离蛋白的水解工具酶;其最佳酶解参数为:酶解温度55℃、初始pH7.0、底物浓度12%、酶添加量8%、植物蛋白酶与木瓜蛋白酶的质量之比为1∶2,水解度可达14.20%;用双蛋白酶水解大豆分离蛋白,水解度为14.71%的产物降胆固醇活性最高,对胆固醇胶束溶解度的抑制率为61.67%。

Plant protease and papain were regarded as the compound enzyme of soy protein isolate（SPI） in comparison with hydrolysis effects of four kinds of protease. The premium working conditions for enzymolysis were determined by means of single factor and L9 （ 3^4 ） orthogonal experiments. The optimal enzymic hydrolysis parameters were as followes ： hydrolysis temperature55℃ ,initial pH 7.0,substrate concentration 12%, proteinase quantity 8%, the mass ratio of plant protease to papain 1：2. Under the optimized conditions, the hydrolysis rate reached 14.2%. The hypocholesterolemic activity of the hydrolysate of SPI with 8.27 % - 16.57 % DH prepared by two protease was studied. The results indicated that the sample prepared by hydrolyzing SPI with two protease at DH = 14.71% shown highest hypocholesterolemic activity among all the samples, the inhibitory ratio of micellar solubility of cholesterol was 61.67% .