Evaluation of wheat gluten hydrolysates as taste-active compounds with antioxidant activity

Wheat gluten was subjected to enzymatic hydrolysis with various proteases (Alcalase, Flavourzyme, Protamex) and the taste-enhancing properties and antioxidant activities of the resulting wheat gluten hydrolysates (WGHs) were characterized. The contents of the hydrophobic amino acid of the WGHs were highly correlated with the degree of hydrolysis by Flavourzyme and Protamex, except Alcalase. The taste profiles of the Alcalase-treated WGHs showed decreased bitterness while umami and overall acceptability increased. On the other hand, the WGHs produced by Flavourzyme and Protamex showed increased bitterness with increasing hydrolysis duration. However, taste profiles, such as umami, kokumi, and overall acceptability of the WGHs by Flavourzyme and Protamex were unaffected by the degree of hydrolysis. The WGH treated by Alcalase for 24 h (A24h) exhibited taste-enhancing property and its antioxidant effects were concentration-dependent. As a result, the A24h may be used as a multi-functional seasoning ingredient having potential antioxidant activity.