Hydrolyzed Proteins From Brewer's Spent Yeast as an Ingredient With Bioaccessible Antihypertensive and Neuroprotective Properties

The aims of this work were to obtain bioactive peptides from brewer's spent yeast (BSY) proteins and to evaluate their antihypertensive and neuroprotective properties before and after the simulated gastrointestinal digestion (SGID) and in vitro colonic fermentation (CF) process. For this, BSY proteins and subsequently a hydrolysate (AF) were obtained. After the SGID and CF, two types of dialysates were obtained, representing the bioaccessible intestinal (D‐AF) and colonic (CD‐AF) peptides. All samples showed antihypertensive activity, which was reduced after SGID, ACE‐I‐IC 50 values being 6.2 ± 0.2 and 8.7 ± 0.7 mg protein mL −1 for AF and D‐AF, respectively. In contrast, the ACE‐I‐IC 50 value obtained for CD‐AF was the lowest one (0.55 ± 0.1 mg protein mL −1 ), indicating that CF increased the antihypertensive activity. The SGID increased the tyrosinase (TYR) and prolyl oligopeptidase (POP) inhibitory properties of BSY peptides, while the CF increased the acetylcholinesterase enzyme (AChE) inhibitory activity. In this regard, the AChE‐IC 50 value obtained for CD‐AF was 0.35 ± 0.05 mg protein mL −1 . The high AChE inhibitory activity of CD‐AF was due to hydrophilic peptides containing Lys with low molecular weight (< 1 kDa). The complete digestive process improved the antihypertensive and neuroprotective properties of BSY peptides. Thus, BSY protein hydrolyzate resulted in a good source of bioaccessible antihypertensive and neuroprotective peptides useful as a biofunctional ingredient for developing functional foods, since peptide bioactivity was enhanced after the complete digestive process.