Abstract:The polyphenols in coriander were extracted using ultrasound-assisted extraction method，and the optimal extraction process for coriander polyphenols was determined through single-factor and orthogonal experiments.The total antioxidant capacity of coriander polyphenol extract was measured using the iron reduction/antioxidant capacity analysis method，and the hydroxyl radical scavenging capacity was determined using the o-phenanthroline method.The antibacterial activity of coriander polyphenols was determined using the filter paper sheet method.The results showed that the optimal conditions for ultrasound-assisted extraction of coriander polyphenols were as follows：the solid-to-liquid ratio of 1∶16（g/mL），ethanol volume fraction of 75%，and extraction time of 60 min.Under these conditions，the extraction yield was（13.11±0.19）mg/g.The antioxidant test results showed that the total antioxidant capacity and hydroxyl radical scavenging rate of coriander polyphenol extract increased with increasing concentration.The total antioxidant capacity of coriander polyphenol extract at a concentration of 0.6 mg/mL was（102±2）μmol/L，and the hydroxyl radical scavenging rate was（60±1）%.The antibacterial test results showed that coriander polyphenols had inhibitory effects on Escherichia coli and Staphylococcus aureus，and the antibacterial activity increased with increasing polyphenol concentration.The inhibition zone diameter of the coriander polyphenol extract at a concentration of 0.6 mg/mL against E.coli was（6.76±0.02）mm，and the inhibition zone diameter against S.aureus was（7.04±0.02）mm.