Enzymatic preparation and antioxidant activity in vitro of brewer's spent grain antioxidant peptides.

The characteristic of enzymatic hydrolyzed brewer's spent grain(BSG) protein was studied.Four microbial proteinases(Alcalase,Flavourzyme,Neutrase and Protamex) were chosen,the change of degree of hydrolysis(DH) and the change of reducing power(RD) were measured.Alcalase had the powerful hydrolyzed ability for BSG protein,and the DHmax was almost got at 3h.The change of DHs had no corresponding relation with RD.RDs were fluctuated near DHmaxs,and RDmaxs almost presented about times when inflexions appeared as DH curves.Antioxidant activity had no corresponding relation with the change of DHs.