Abstract:In order to study the functional components and in vitro antioxidant activity of sea-buckthorn Jiaosu，changes in total acid，total free amino acid and total flavonoid as well as scavenging abilities on superoxide radical，hydroxyl radical and DPPH radical during fermentation of sea-buckthorn Jiaosu were investigated；species and concentration of organic acids and free amino acids of sea-buckthorn Jiaosu were analyzed using high performance liquid chromatography；in vitro antioxidant activity of sea-buckthorn Jiaosu after 60 days of fermentation was assessed in comparison with the control（ascorbic acid）.During fermentation，scavenging ability on superoxide radical，hydroxyl radical and DPPH radical all presented a rising tendency.The level of total acid，total free amino acid and total flavonoid showed an increasing trend generally，which was （32.493±0.64）mg/mL，（3.059±0.07）mg/mL and （0.570±0.01）mg/mL respectively on the 60thday.DPPH radical scavenging ability showed very strong positive correlations with both total acid content and total free amino acid content（p<0.01，the spatial correlation coefficient was 0.947 and 0.956 respectively）.The main organic acid in sea-buckthorn Jiaosu was L-malic acid of（11.262±0.23）mg/mL，while the main free amino acid was glutamic acid of（1.257±0.05）mg/mL.Scavenging abilities on superoxide radical，hydroxyl radical and DPPH radical all exhibited a dose-dependent manner，and the IC50of these indices were 4.049 mgVC/mL，2.554 mgVC/mL，0.406 mgVC/mL respectively.In the experimental concentration range，the hydroxyl radical scavenging ability and DPPH radical scavenging ability of sea-buckthorn Jiaosu were better than the control（ascorbic acid）.