Bioaccessible bioactive compounds with antioxidant, antihypertensive, and neuroprotective properties from barley-malt beverages germinated under different conditions

Abstract

Bioactive compounds (phenolics, bioactive peptides, and γ-aminobutyric acid (GABA)) from beverages prepared using two different barley malts (brewery malt, MB1, or bioactive malt, MB2) and their gastrointestinal and colonic bioaccessibility were evaluated after in vitro digestion. Beverages were produced using the enzymatic potential of malts. After mashing, a higher degree of protein hydrolysis was achieved using MB1 (9.05 vs 2.23 %), with total phenolic compound content remaining the same for both malts (3.9 mg/100 mL). Additionally, GABA increased 2.0 and 2.6 times for MB1 and MB2, respectively. The beverages presented antioxidant (ABTS+ scavenging and ferric reducing antioxidant power (FRAP)), antihypertensive (angiotensin-converting enzyme-I (ACE-I) inhibition), and neuroprotective (acetylcholinesterase (ChE), tyrosinase (TYR), and prolyl oligopeptidase (POP) inhibition) activities after in vitro gastrointestinal digestion. MB1 had higher antioxidant activity for both methods evaluated, and MB2 exhibited higher neuroprotective activity for TYR and POP inhibition, while no differences were obtained for ACE-I and AChE inhibitions between both beverages. The bioactivity was related to bioactive peptides and phenolic compounds released by the process. After colonic fermentation, MB1 generated higher short-chain fatty acid (SCFA) content per fiber gram than MB2. Therefore, when used for beverage production, MB1 would provide greater antioxidant capacity and SCFA generation, while MB2 would provide greater neuroprotective activity.