ANGIOTENSIN-I-CONVERTING-ENZYME INHIBITORY PEPTIDES DERIVED FROM BOVINE-MILK PROTEINS

Milk whey and casein proteins were fermented with different lactic aci d starters and digestive enzymes. ACE-inhibition activity was observed only after the digestion of proteins with pepsin and trypsin. Whey pr oteins resulted in 35-61% inhibition and caseins 86% inhibition under the applied conditions. The hydrolysates having inhibitory activity we re fractionated by size exclusion and reversed phase chromatography. S everal ACE-inhibitory peptides were purified and identified by amino a cid and MS-analysis. The identified peptides were alpha-la f105-110, b eta-lg f9-14, f15-20, alpha(s1)-cn f142-147, f157-164, f194-199 and be ta-cn f108-113, f177-183 and 193-198. Among whey hydrolysates peptides with small molecular weight (<1000 Da) were the most active inhibitor s. The highest ACE-inhibitory activity was found in the peptides deriv ed from alpha(s1)-casein. (C) 1998 Elsevier Science Ltd. All rights re served.