New potentially antihypertensive peptides liberated in milk during fermentation with selected lactic acid bacteria and kombucha cultures

Abstract

Compounds with the ability to inhibit angiotensin-converting enzyme (ACE) are used medically to treat human hypertension. The presence of such compounds naturally in food is potentially useful for treating the disease state. The goal of this study was to screen lactic acid bacteria, including species commonly used as dairy starter cultures, for the ability to produce new potent ACE-inhibiting peptides during milk fermentation. Strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus, Lactobacillus paracasei, Lactococcus lactis, Leuconostoc mesenteroides, and Pediococcus acidilactici were tested in this study. Additionally, a symbiotic consortium of yeast and bacteria, used commercially to produce kombucha tea, was tested. Commercially sterile milk was inoculated with lactic acid bacteria strains and kombucha culture and incubated at 37°C for up to 72 h, and the liberation of ACE-inhibiting compounds during fermentation was monitored. Fermented milk was centrifuged and the supernatant (crude extract) was subjected to ultrafiltration using 3- and 10-kDa cut-off filters. Crude and ultrafiltered extracts were tested for ACE-inhibitory activity. The 10-kDa filtrate resulting from L. casei ATCC 7469 and kombucha culture fermentations (72 h) showed the highest ACE-inhibitory activity. Two-step purification of these filtrates was done using HPLC equipped with a reverse-phase column. Analysis of HPLC-purified fractions by liquid chromatography-mass spectrometry/mass spectrometry identified several new peptides with potent ACE-inhibitory activities. Some of these peptides were synthesized, and their ACE-inhibitory activities were confirmed. Use of organisms producing these unique peptides in food fermentations could contribute positively to human health.

Angiotensin‐converting enzyme inhibition, antioxidant activity and cytotoxicity of bioactive peptides from fermented bovine colostrum

“…In similar studies, antihypertensive properties of kefir‐fermented milk were showed to be in close dependence with peptides size and their proteolysis during product storage led to a sharp decrease in ACE inhibitory activity (Sanli et al ). Thus, it was reported a significantly higher ACE inhibition activity of milk peptides with MW lower than 10 kDa, compared to those with MW lower than 3 kDa (Elkhtab et al ). HPLC‐tandem mass spectrometry identified two hydrophobic peptides with sequences PYVRYL and LVYPFTGPIPN released from caprine kefir caseins, which showed high ACE inhibitory properties (Quiros et al ).…”

Anti-hypertensive peptides released from milk proteins by probiotics

“…However, whey fermented with Lactobacillus brevis produced a different peptide AEKTK, but also with ACE-I activity [62]. Additionaly, using Lactobacills casei and kombucha cultures resulted in 21 new peptides (6-18 amino acids in length) of which LVESPPELNTVQ, VLESPPELN, WGYLAYGLD were confirmed to have ACE-I activity [66].…”

Protective Effect of Prunus mume Fermented with Mixed Lactic Acid Bacteria in Dextran Sodium Sulfate-Induced Colitis

“…In a previous study, Lizardo et al (2020) [18] reported that mixed LAB-fermented cherry silverberry extract showed the effective production of viable lactobacillus compared to mono LABfermentation under harsh conditions such as acidity and low pH. In addition, the pH decreased and the cell counts increased during the LAB-fermentation of kombucha [26]. Mixed-fermentation with LAB strains using food materials contributed to higher survival rates than mono-fermented cells.…”