Significance of proteolytic microorganisms on ACE-inhibitory activity and release of bioactive peptides during fermentation of milk

In this study, bacterial isolates i.e. Lactobacillus rhamnosus (NS4 and NS6), Lactobacillus helveticus MTCC 5463 (V3), Lactobacillus delbruckii (009), Enterococcus faecalis (ND3), Enterococcus faecalis (ND11) and Lactobacillus rhamnosus (SH8) were evaluated for their proteolytic activity, ACE-inhibitory activity and release of peptides during fermentation of skim milk under specified growth conditions. Lactic acid bacteria have a strong proteolytic system. However, NS4 and OO9 showed maximum proteolytic activity and ACE inhibitory activity compared to other isolates. Water soluble extract derived from fermented milk exhibited bioactive peptides. OO9 showed maximum peptides separation compared to other isolates during RP-HPLC analysis. These peptides produced by the isolates may be responsible for showing ACE inhibitory activity .