核桃粕中多肽的酶法制备工艺

The Enzymatic Preparation of Polypeptide in Walnut Residue

探索生物酶法水解核桃蛋白制备核桃多肽的工艺。以酶解蛋白的水解度和氮溶指数作为考察指标,单因素筛选核桃蛋白水解酶、反应底物的液料比、酶解时间等条件,优化酶水解核桃蛋白及制备核桃多肽的提取的工艺参数。选用胰蛋白酶作为核桃蛋白的水解酶,酶解条件为:pH 7.0,温度45℃,液料比10∶1 (mL/g),酶解时间240 min,添加量4 000 U/g。该条件下改性后的核桃蛋白氮溶指数为69.61%,水解度为39.31%,提取的多肽分子量小于1 450 Da的含量为36.33%。基于酶水解法,此次试验的提取工艺合理可行,为核桃多肽的提取提供了理论依据。

To explore the extraction process of enzymatic hydrolysis of walnut protein to obtain walnut polypeptide,taking hydrolysis degree and nitrogen solubility index of hydrolyzed protein as the investigation index,the extraction process parameters of walnut polypeptide were optimized by single factor screening of walnut protein hydrolase,liquid ratio of reaction substrate and enzymolysis time.Trypsin was selected as the hydrolysate.The hydrolysis conditions were pH 7.0,temperature 45℃,ratio of liquid to material 10∶1(mL/g),enzymatic hydrolysis time 240 min,and adding amount 4 000 U/g.The nitrogen solubility index of modified walnut protein was 69.61%,while the degree of hydrolysis was 39.31%,and the content of polypeptide molecular weight less than 1 450 Da was 36.33%.Based on the method of enzymatic hydrolysis,the extraction process of walnut polypeptide was reasonable and feasible,which provided the theoretical basis for extraction of walnut polypeptide.