核桃粕蛋白抑菌肽的制备工艺及纯化

为探究具有抑菌作用的核桃粕蛋白酶解抑菌肽的制备工艺，本实验以核桃仁经压榨提油后的副产物-核桃粕为原材料，利用酶解法制备核桃粕蛋白抑菌肽，优化制备工艺，进一步分离纯化，测试抑菌肽对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌的抑制效果，筛选出具有最佳抑菌效果抑菌肽组分。研究结果表明:响应面优化胃蛋白酶酶解核桃粕工艺最佳条件为:温度54℃，pH3.46，加酶量5475.71 U/g，蛋白质水解度最优，可达13.99%；利用超滤技术对酶解肽分离纯化，得到4种不同分子量的酶解肽，抑菌实验表明H-Ⅱ （分子量为3~10 kDa）范围的酶解肽抑菌效果显著高于其他分子量范围的酶解肽（P<0.05）。本研究为核桃粕的深入研究利用以及新型抑菌肽产品的开发提供了数据支撑。

Preparation and Isolation of Antibacterial Peptides from Wulnut Dregs Protein

The preparation process of walnut dregs protein enzymatic bacteriostatic peptide with antibacterial activity was explored.In this experiment,walnut dregs,a by-product of walnut kernel after extraction of oil was used as raw materials to obtain walnut protein antibacterial peptide by enzymatic hydrolysis,the preparation process was optimized and the antibacterial peptide was further purified.The inhibitory effect of the antibacterial peptide against Escherichia coli,Staphylococcus aureus and Bacillus subtilis were tested,and the antibacterial peptide component with the best bacteriostatic effect was selected.The results showed that,the optimal conditions for the pepsin enzymatic hydrolysis process were:Temperature of 54℃,pH of 3.46,enzyme dosage of 5475.71 U/g,which exhibited the highest degree of protein hydrolysis,up to 13.99%.The separation and purification of enzymatic peptides were carried out by ultrafiltration technology,and four enzymatic peptides with different molecular weights.The bacteriostatic experiments showed that the antibacterial effect of H-II(molecular weight 3~10 kDa)was significantly higher than that of other molecular weight ranges(P<0.05).This study would provide the data support for the in-depth research and the development of walnut meal.