Small Peptides Isolated from Enzymatic Hydrolyzate of Fermented Soybean Meal Promote Endothelium-Independent Vasorelaxation and ACE Inhibition

Abstract

Fermentation of soybean is a process in which soy proteins are broken down into small peptides to exert various physiological functions beyond their nutritional value and to improve food source bioactive components responsible for health benefits. Enzymatic hydrolysis could speed up the degradation of proteins during fermentation of soybean, thus resulting in higher peptide production. In the present study, fermented soy meal (fermented with Bacillus subtilis from Douchi) was hydrolyzed by thermolysin, and the water extraction was then separated into four fractions using ultrafiltration membranes. Their vasorelaxation activities were screened, and the most potent fraction was further isolated and purified to obtain four peptides. Briefly, three peptides exerted a dose-dependent vasorelaxation (0.01-4.10 μM) in the phenylephrine preconstricted thoracic aorta ring of Sprague-Dawley rat (relaxation actions were all endothelium-independent), while one peptide induced vasoconstriction. Furthermore, an independent causal relationship between vasorelaxation and angiotensin converting enzyme (ACE) inhibition activities was found.

Effects of liquid protein feed on growth performance and ruminal metabolism of growing lambs fed low-quality forage and compared to conventional protein sources

“…The improved fibre digestion in SBM-fed lambs could also be an effective factor in improving gain. Soybean meal is a protein source which could produce relatively high peptide levels (Wang et al ., 2017). Addition of a peptide source in continuous culture has been reported to increase branched chain volatile fatty acid (BCVFA) production (Griswold et al ., 1996), which has potential for increasing fibre digestion (Gorosito et al ., 1985).…”

Newly manufactured Marukome MK-34-1 miso with angiotensin-converting enzyme inhibitory activity and its antihypertensive effects in genetic hypertensive rat models

“…The main objective of this study was to produce new miso with hypotensive effects by modifying the fermentation process. Many studies have reported that there is ACE inhibitory activity in enzyme-hydrolyzed fermented soybean or dipeptides derived from soybean [17][18][19]. To our knowledge, however, there have been few studies in vivo on the involvement of ACE inhibition in BP reduction by miso.…”

Synergism of microorganisms and enzymes in solid-state fermentation of animal feed. A review

“…However, the impact of antinutritional factors can be decreased and the nutritional value can be improved by adding fibrolytic enzymes and lactic acid bacteria to the fermentation process (Cheng et al, 2019). By such treatments, the protein of soyabean meal can be degraded into numerous kinds of small peptides by fermentation, as well as the content of angiotensin-converting enzyme can be increased to ensure animal health (Wang et al, 2017). After the co-fermentation and decomposition by Lactobacillus plantarum, Bacillus subtilis and Saccharomyces cerevisiae, soyabean meal can be widely used in piglet feeding without affecting the daily gain of piglets, but augmenting their immune ability and promoting the development of small intestinal epithelial cells (Zhu et al, 2017).…”