Binary mixture of proteases increases the antioxidant properties of white bean (Phaseolus vulgaris L.) protein-derived peptides obtained by enzymatic hydrolysis

In this study, hydrolysates from white bean protein concentrate were obtained using the commercial proteases Flavourzyme® 500 L, Alcalase® 2.4 L and Neutrase® 0.8 L and a statistical mixture design. The antioxidant properties of the protein hydrolysates, the modulation of the protease activities by substrates and products and the antioxidant activities of fractionated samples by ultrafiltration were investigated. The results showed that the antioxidant activities of the white bean protein increased from 45% to 70% after enzymatic hydrolysis. The use of the binary mixture of Flavourzyme® 500L and Alcalase® 2.4 L showed a significant synergistic effect and resulted in maximum antioxidant activity of the protein hydrolysates when evaluated by DPPH-radical scavenging and reducing power assay. It was observed that proteins from white bean decreased the t1/2 and D values of the enzymes and their combinations during enzymatic hydrolysis. For the fractionated samples, a tendency was observed to show less antioxidant activities with a reduction in molecular weight, reaching the lowest values in the 3 kDa permeate fraction. This study demonstrated the usefulness of statistical mixture design in the production of protein hydrolysates with improved antioxidant properties.