Abstract：For 12 kinds of brewing vinegar in four brands and different years which were purchased from market, the analysis of the changes in their six indexes were performed, which include total polyphenols, flavonoids, total oxidation value, 1,1diphenyl2picrylhydrazyl free radical（DPPH〖DK〗·）, hydroxyl free radical (〖DK〗·OH) and superoxide anion (O2〖DK〗·) clearance. And by analyzing correlation, doing principal component analysis,their antioxidant properties were evaluated. The results showed that with the aging time increasing, the clearance rate of three free radicals of Zhenjiang vinegar increased, Z10>Z6>Z3, whereas the content of total flavonoids, total polyphenols and total antioxidant capacity were Z10>Z3>Z6. Six indexes of Sichuan bran vinegar showed that 5 year old vinegar was better than 3 year old vinegar. The content of total flavonoids, total polyphenols and total antioxidant capacity in Shanxi aged vinegar were positively correlated with the aging time, O2· and DPPH radical clearance showed S3>S10>S5, and ·OH clearance trend was S10>S3>S5. There was no obvious rule between the changes of 6 indexes and the aging time of single aged vinegar products. The content of total flavonoids, total polyphenols and total antioxidant capacity all presented D4>D8>D3>D5, O2·and ·OH scavenging rates were D5>D4>D8>D3,and DPPH radical scavenging rates were D5>D8>D4>D3.Correlation analysis showed that the total polyphenols and total flavonoids in all products tested were significantly correlated. Principal component analysis showed that O2·clearance and DPPH radical clearance had a highly positive correlation with component 2, ·OH clearance, total polyphenols and total flavonoids had a highly negative correlation with PC2, and all the above variables had a good positive correlation with PC1. This paper can provide theoretical basis and technical support for the study of antioxidant properties of brewing vinegar.
