罗非鱼鱼鳞胶制备降血压胶原肽的工艺及酶解物活性

以罗非鱼鱼鳞胶为原料,制备对血管紧张素转换酶(ACE)有抑制活性的降血压肽。以水解度(DH)及ACE抑制率为指标,筛选水解鱼鳞胶的最适酶种,并对其水解工艺条件进行优化;采用超滤技术对所制备的降血压肽进行分离纯化,比较不同组分的ACE抑制率,测定高ACE抑制率组分的氨基酸组成,并运用MALDI-TOF-MS法分析其分子质量分布。结果表明,复合蛋白酶是水解鱼鳞胶最适酶种,在50℃、pH7.5、料液质量体积比1∶5、酶与底物质量比(mE/mS)1.5%条件下,酶解6 h,酶解液的ACE抑制作用最强,其水解度DH 73%,ACE的抑制率76.15%。酶解液经超滤分离所获得的分子质量小于2 000 u的组分对ACE抑制率最高,达83.15%;该组分的氨基酸主要含有Gly和Pro,含量分别为22.04%和11.40%;该组分分子质量范围为1 300~2 000 u。

Preparation and Characterization of Anti-hypertensive Peptides from Scale Collagen of Oreochromis niloticus

The technology for preparation of antihypertensive peptides by hydrolyzing scale collagen from Oreochromis niloticus with optimum enzyme was optimized by using the index of hydrolysis degree(DH) and ACE inhibitory rate.The hydrolysates were separated by different ultrafiltration strain membrane,and the ACE inhibitory activities were measured.Then amino acid composition and molecular mass of the strongest anti-hypertension substances were determined.The results showed that the compound protease had the best hydrolyzing capacity;the optimum hydrolysis conditions were as follows: 50 ℃,pH 7.5,solid-liquid ratio 1∶5,the mass ratio of enzyme to substrate(mE/ mS) 1.5%,6 h.Under these conditions,the DH was 73% and ACE inhibitory rate was 76.15%.In addition,the results indicated that the fraction with molecular mass distribution under 2 000 u had the strongest ACE inhibitory activity,reaching up to 83.15%.The amino acid composition mainly consisted of Gly and Pro,respectively reaching to 22.04% and 11.40%,and the distribution of molecular mass was 1 300-2 000 u.