Separation and purification of ACE inhibitory peptides from casein

ACE inhibitory peptides prepared by alkaline protease enzyme on casein were studied in this article.Optimized by orthogonal test,the optimum enzymatic hydrolysis conditions were:temperature 50 ℃,pH value 7.5,enzyme dosage 5%,substrate concentration 5%,under this conditions,the ACE inhibitory activity was 47.23%.Use of ultrafiltration on hydrolyzate for initial separation,obtained the molecular weight of less than 4 ku components,its ACE inhibitory activity was 57.34%.With gel filtration SephadexG-25 for further purification,the purified components of ACE inhibitory activity up to 62.78%,24.77% higher than the original hydrolysates,and its relative molecular weight was 1 500 u below.