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

Abstract

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.

Effects of fermentation conditions on the potential anti‐hypertensive peptides released from yogurt fermented by Lactobacillus helveticus and Flavourzyme®

“…4a,b), ACE-I activity in yogurt without L. helveticus was lower than that in yogurt with L. helveticus (Fig. These results were consistent with the recent study by Ahtesh et al (2016b) using the same strains in the fermentation of 12% of RSM (Ahtesh et al, 2016b;Tsai et al (2008) Figure 4 The HPLC chromatogram of peptide profile (20 mg mL À1 ) obtained from normal yogurt (a) and yogurt added with L. helveticus without Flavourzyme Ò (b) and with Flavourzyme Ò (c) after 12 h fermentation at 37°C. Many anti-hypertensive milk peptides have been isolated and identified (Hannu & Anne, 2006).…”

“…2a). In agreement with this result, a previous study showed that ACE-I reached the highest level (approximate 70%) after 12 h fermentation of RSM by L. helveticus strain 881315 without Flavourzyme Ò addition; however, more than 70% ACE-I activity was obtained after only 4 h fermentation by the same strain with the supplementation of Flavourzyme Ò (Ahtesh et al, 2016b). 2a).…”

“…The pH was further decreased to 4.06 AE 0.03 when Flavourzyme Ò and L. helveticus strains were added in the yogurt for 16 h of fermentation (P < 0.01; Fig. Previous research has demonstrated the same trends using these L. helveticus strains in the 12 h fermentation of skim milk and the pH of the fermented product was 3.4 when Flavourzyme Ò was added compared with 5.0 without addition of Flavourzyme Ò (Ahtesh et al, 2016b). The decrease of the pH could be due to the production of lactic acid by lactic acid bacteria strains (Donkor et al, 2007a).…”

“…1a). This was possibly due to the low pH and heat treatment reducing available nutrients for growth (Dissanayake et al, 2013;Ahtesh et al, 2016b). The pH of yogurt in the presence of Flavourzyme Ò was significantly lower than that without Flavourzyme Ò for the same fermentation time (P < 0.01; Fig.…”

“…The decrease of the pH could be due to the production of lactic acid by lactic acid bacteria strains (Donkor et al, 2007a). In this study, yogurt was used as a media while RSM was used in the study by Ahtesh et al (2016b). 1a).…”