Antioxidant activities of enzymatic rapeseed protein hydrolysates and the membrane ultrafiltration fractions

► Alcalase and proteinase K were the most effective enzymes for converting rapeseed proteins into antioxidant peptides. ► Low molecular weight peptides (<1 kDa) were more effective radical scavengers than peptides >1 kDa in size. ► Peptides with sizes >3 kDa were the more effective iron chelators than peptides <3 kDa in size. ► The protein hydrolysates effectively inhibited linoleic acid oxidation up to five days before losing antioxidant activity.