Abstract:  Soybeans were processed into Douchi,a traditional Chinese food.The DPPH(2,2-diphenyl-1-picrylhydrazyl hydrate)radical-scavenging activity and ABTS [2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)] radical-scavenging activity of 50% ethanol extracts of Douchi were assayed during the pretreatments(soaking and boiling),fermentation with Aspergillus oryzae(AS3.951)and salt supplement.The effects of process technic on the antioxidant activity of Douchi were evaluated.The antioxidant activity of soybean changes a little affer soaking and boiling.However,a remarkable increase of the antioxidant activity of Douchi was observed during the koji fermentation.In the process of fermentation ripening,the antioxidant activity of Douchi increases.After adding salt into Douchi,the antioxidant activity of Douchi decreases with the increase of salt content.

Key words:  , Douchi； antioxidant activity； DPPH； ABTS； process technic；