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.

The development of agricultural products as well as the industrialization of food production have led to dramatic lifestyle changes, particularly in dietary patterns, which in turn has increased the occurrence of chronic diseases and hypertension. In order to help overcome this, the food industry has developed functional milk products. Milk products, particularly fermented milk containing probiotics, are popular. Probiotics may promote gut health, reduce allergenicity, increase the bio-accessibility of fats/proteins in foods, and lower blood pressure because they contain poly-amines and bioactive peptides. Bioactive peptides have been shown to lower the risk of hypertension and cancer. Herein, we discuss the potential role of fermented milk as a functional drink acting against hypertension. However, longer-term research studies are necessary to evaluate the role of fermented milk drinks in supporting human health.

Summary This study was carried out to examine the proteolytic and angiotensin‐converting enzyme (ACE‐I) activities of probiotic lactic acid bacteria (LAB) as influenced by the type of media, fermentation time, strain type and media supplementation with a proteolytic enzyme (Flavourzyme®). Lactobacillus casei (Lc210), Bifidobacterium animalis ssp12 (Bb12), Lactobacillus delbrueckii subsp. bulgaricus (Lb11842) and Lactobacillus acidophilus (La2410) were grown in 12% of reconstituted skim milk (RSM) or 4% of whey protein concentrates (WPC‐35) with or without combination (0.14%) of Flavourzyme® for 12 h at 37 °C. All the strains were able to grow in both media depending on type of strains used and fermentation time. All the strains showed higher proteolytic activity and produced more antihypersensitive peptides when grown in RSM medium at 12 h, when compared to WPC. Combination with Flavourzyme® also increased LAB growth and proteolytic and ACE‐I activities. Of the four strains used, Bb12 and La2410 outperformed Lc210 and Lb11842. The highest ACE‐I activity and proteolytic activity were found in B. animalis ssp12 combined with Flavourzyme®. Flavourzyme® led to an increase in the production of bioactive peptides with ACE‐I activity during 12 h at 37 °C.

Sensory evaluation is an important task for manufacturers to improve the product quality of new functional fermented milk drinks (FFMD) containing angiotensin-converting enzyme inhibitory (ACE-I) bioactive peptides produced during milk processing by enzymatic/mechanical hydrolysis. Herein, a fermented reconstituted skim milk (RSM) was made with Lactobacillus helveticus supplemented with Flavourzyme â using a bioreactor to improve cell viability and levels of ACE-I bioactive peptides. Sensory evaluations of three different fermented RSM drink samples were conducted by 20 trained panellists. There were no significant differences in flavour, bitterns, appearance and acceptance of FFMD compared to the commercial product Yakult â . Addition of sucrose and flavour provided positive changes in terms of acceptability by consumers.

Seven strains of selected probiotic bacteria were separately combined with Kluyveromyces marxianus LAF4 to ferment 12% reconstituted skim milk (RSM) at 37°C for 0-12 h. The growth characteristics of the probiotic strains and K. marxianus, pH levels, proteolytic activity and angiotensinconverting enzyme inhibitory (ACE-I) activity of the fermented RSM were measured. The highest ACE-I activity of 60% was for K. marxianus at 37°C for 12 h (P < 0.005) when compared to K. marxianus in combination with the probiotic bacterial strains.