Optimized PEF treatment for antioxidant polypeptides with MW 10-30Â kDa and preliminary analysis of structure change

► OFAT tests and RSM analysis based on a BBD were designed perfectly. ► FRAP value was used to evaluate antioxidant activity. ► PEF technology was applied to improve antioxidant activity of polypeptides. ► NIR and MIR were used to analyze the change of functional groups.