Preparation and assessment of bioactive extracts having antioxidant activity from rice bran protein hydrolysates

Abstract

Rice bran protein concentrate (RBPC) was digested using four commercial enzymes, Alcalase, Trypsin, Protamex, and Flavourzyme at a various digestion time (2, 4, and 6 h), in order to produce antioxidant active peptides. The degree of hydrolysis (DH), total phenolic content (TPC), and antioxidant activity, including DPPH, ABTS, and metal chelating assays were examined. The obtained results indicated that DH varied with the type of enzyme used, Protamex > Trypsin > Alcalase > Flavourzyme, respectively. The optimum conditions of hydrolysis was 2 h using Flavourzyme, which gives protein content of 62.90 ± 0.77 mg/100 g, TPC of 893.75 ± 0.57 mg GAE/100 g, DPPH of 83.68 ± 0.97%, ABTS of 35.11 ± 0.66%, and a metal chelating activity of 53.90 ± 0.13%. These results indicate that the hydrolysate produced by digesting RBPC using Flavourzyme may contain bioactive components useful as natural food antioxidants. That can increase their potentials as natural food additives which could be useful in the food industry sector.