酶法制备阿拉斯加鳕鱼降压肽的工艺优化及其产物的结构鉴定

以体外血管紧张素转化酶(ACE)抑制率为指标,筛选出制备阿拉斯加鳕鱼降压肽的最优酶。本研究通过正交实验以及单因素优化实验确定了阿拉斯加鳕鱼降压肽的最优酶解工艺,考察了最优工艺降压肽的氨基酸含量与分子量分布范围。结果表明:在菠萝蛋白酶、木瓜蛋白酶、胰蛋白酶、复合蛋白酶、碱性蛋白酶和酸性蛋白酶6种蛋白酶中,经胰蛋白酶酶解得到的降压肽ACE抑制率最高,为68.48%,其中影响胰蛋白酶活性大小的因素依次为温度、酶与底物质量比、料液比、pH和时间,最优酶解温度40℃,酶与底物质量比3%,料液比1:7,pH=7,酶解时间2 h。在此工艺条件下,降压肽ACE抑制率可达79.62%,氨基酸总含量为83%,分子量低于500 Da的降压肽可达到70.74%。优化的阿拉斯加鳕鱼降压肽的提取工艺可行、合理,降压肽也具有较高的体外ACE抑制活性。本研究结果为进一步考察食源性降压肽提供了参考。

Extraction Optimization and Structure Identification of Anti-hypertensive Peptide from Alaskan Cod by Enzymatic Method

The technology for preparation of anti-hypertensive peptides from Alaska cod skins with optimum enzyme was optimized by using the index of ACE inhibitory rate in vitro. In this study,the optimal enzymatic hydrolysis process of anti-hypertensive peptides from Alaskan cod was determined by single-factor and orthogonal experiments,and the amino acid content and molecular weight distribution range of anti-hypertensive peptides were investigated. The results showed that the trypsin had the best hydrolyzing capacity,the ACE inhibition rate reached a constant value of 68.48%. And the optimum hydrolysis conditions were as follows:Hydrolysis temperature 40℃,the ratio of enzyme to substrate 3%,the ratio of solid to liquid 1:7,pH7,hydrolysis time 2 h. Under these conditions,the ACE inhibition rate was 79.62%,content was 83%,the relative molecular weight below 500 Da was 70.74%,respectively. The optimized extraction process of anti-hypertensive peptides from Alaskan cod was feasible and reasonable. The results of this study could provide a reference for further investigation of food-derived anti-hypertensive peptides.