Preparation of enzymatic pretreated corn gluten meal hydrolysate and in vivo evaluation of its antioxidant activity

• Hydrolysate of corn gluten meal exhibiting high antioxidant activity was prepared.
• Soaking with Na2CO3 solution, starch removal, and cooking are used as pretreatments.
• Enzymatic catalysis by proteases at substrate protein concentration of 13.5% (w/w).
• Molecular weight of the peptides in hydrolysate was 1200–250 Da.
• It exhibited good antioxidant activity both in vitro and in vivo.

Corn gluten meal (CGM) is a major by-product of corn wet milling. Pretreatments of CGM by Na2CO3, starch removal, and cooking reduced the total starch and fat by 93% and 78%, respectively. Higher antioxidant hydrolysate was prepared by using Alcalase, Protamex and Flavourzyme at a substrate concentration of 13.5% (w/w). The degree of hydrolysis reached 29.49% and 27.11%. The peptides in hydrolysate were in the range of 1200–250 Da. It increased the activities of superoxide dismutase, glutathione peroxidase, and reduced MDA equivalents of mice at a dose of 300 mg/kg. Therefore, corn gluten can be developed into an antioxidant supplement.