DPPH Radical Scavenging Activity of Extract from Soybean Residue and Coordination Effect

To study the DPPH radical scavenging activity of the extracts from soybean residue and the coordination effect with other antioxidants,DPPH-TLC and DPPH-Microplate assays were used to determine the free radical scavenging activities of the petroleum ether,ethyl acetate,acetone and ethanol extracts from soybean residue.The results revealed that these extracts all had free radical scavenging activities.The DPPH radical scavenging activity of the ethanol extracts was much higher than that of petroleum ether,ethyl acetate and acetone extracts.At concentration of 10.0 mg·mL-1,the ethanol extract from soybean residue could reach 76.48% of 0.4 mg·mL-1 DPPH radicals after incubating at 37℃ for 15 minutes.At the same time,coordination of DPPH radical scavenging activity of the ethanol extract from soybean residue with Vc and citric acid was studied.Vc and citric acid could intensify DPPH radical scavenging activity of ethanol extract from soybean residue.Vc exhibited stronger synergistic effect than that of citric acid.