Effect of Flavourzyme® on Angiotensin-Converting Enzyme Inhibitory Peptides Formed in Skim Milk and Whey Protein Concentrate during Fermentation by Lactobacillus helveticus

Angiotensin-converting enzyme inhibitory (ACE-I) activity as affected by Lactobacillus helveticus strains (881315, 881188, 880474, and 880953), and supplementation with a proteolytic enzyme was studied. Reconstituted skim milk (12% RSM) or whey protein concentrate (4% WPC), with and without Flavourzyme® (0.14% w/w), were fermented with 4 different L. helveticus strains at 37 °C for 0, 4, 8, and 12 h. Proteolytic and in vitro ACE-I activities, and growth were significantly affected (P < 0.05) by strains, media, and with enzyme supplementation. RSM supported higher growth and produced higher proteolysis and ACE-I compared to WPC without enzyme supplementation. The strains L. helveticus 881315 and 881188 were able to increase ACE-I to >80% after 8 h of fermentation when combined with Flavourzyme® in RSM compared to the same strains without enzyme supplementation. Supplementation of media by Flavourzyme® was beneficial in increasing ACE-I peptides in both media. The best media to release more ACE-I peptides was RSM with enzyme supplementation. The L. helveticus 881315 outperformed all strains as indicated by highest proteolytic and ACE-I activities.