核桃蛋白的酶解工艺优化及产物特性研究

Optimization of enzymatic process and product properties of walnut protein

将核桃饼脱脂、碱溶酸沉制备核桃蛋白,再利用碱性蛋白酶对核桃蛋白酶解,采用单因素实验研究底物质量分数、酶解pH、酶用量、酶解温度、酶解时间对水解度的影响,在此基础上采用正交实验对酶解工艺条件进行优化,同时测定了酶解产物的溶解特性、乳化特性和起泡特性。结果表明:碱性蛋白酶酶解核桃蛋白最优酶解条件为底物质量分数5.0%、酶解pH 9.0、碱性蛋白酶(活性为10000 U/g)用量4.0%、酶解温度50℃、酶解时间2 h;相较核桃蛋白,不同水解度的核桃蛋白酶解产物的表面疏水性下降,溶解特性、乳化特性和起泡特性提高。

Walnut protein was prepared from walnut cake by defatting and alkali solubilization and acid precipitation,then it was hydrolyzed by alkaline protease,and the effects of enzymolysis pH,mass fraction of substrate,enzyme dosage,enzymolysis temperature and enzymolysis time on the degree of hydrolysis were studied by single factor experiment,then the enzymatic hydrolysis process was optimized using orthogonal experiment.The solubility,emulsification and foaming properties of the enzymatic hydrolysis products were measured.The results showed that the optimal conditions for the enzymatic hydrolysis of walnut protein with alkaline protease were obtained as follows:mass fraction of substrate 5.0%,enzymolysis pH 9.0,amount of alkaline protease(activity 10000 U/g)4.0%,enzymolysis temperature 50℃and enzymolysis time 2 h.Compared with walnut protein,the surface hydrophobicity of the enzymatic hydrolysis product with different degrees of hydrolysis decreased,and the solubility,emulsification and foaming properties increased.