Feta cheese: A pool of Non-Starter Lactic Acid Bacteria (NSLAB) with anti-hypertensive potential

In the present work, we examined the angiotensin-I-converting enzyme-inhibitory (ACE-I) activity of the water soluble extracts of four long-ripened Feta cheese samples. High activity (>87 %) was determined for all of them. Additionally, we fingerprinted the non-starter lactic acid bacteria (NSLAB) isolated from the cheese samples. All NSLAB isolates were screened for their proteolytic activity and the most proteolytic ones were further evaluated for their ACE-I activity as well as ability to produce γ-aminobutyric acid (GABA). The NSLAB isolates comprised 130 lactobacilli and 24 enterococci, with the dominant species being Levilactobacillus brevis, Lactiplantibacillus plantarum, Lacticaseibacillus paracasei and Enterococcus faecium. Among them, 40 selected isolates exhibited high proteolytic activity, with 13 lactobacilli and two enterococci exhibiting strong ACE-I activity (>50 %), and six lactobacilli producing GABA. Thus, the hypertension risk associated with over-consumption of Feta cheese because of its high sodium content may be compensated by the anti-hypertensive traits of NSLAB microbiota members, which are active during the long cheese ripening time.