Investigation into factors influencing antioxidant capacity of vinegars

Thirty commercial vinegars were investigated in order to study the factors influencing antioxidant capacity. Total phenols and flavonoids, 1,1-diphenyl-2-picrylhydrazyl, and 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging capacity, nitrite scavenging capacity, reducing capacity, and lipid oxidation inhibition method were used. Factor and k-means cluster analysis partitioned the vinegars into three clusters according to antioxidant capacity. Traditional balsamic vinegar (TBV), balsamic vinegar, and tomato vinegar were grouped as cluster 2, which contained the highest antioxidant capacity. Especially, TBV exhibited the highest antioxidant capacity. In high-performance liquid chromatography analysis, cluster 2 also had a high content of polyphenols and 5-hydroxymethylfurfural. These compounds presented positive correlation with the antioxidant capacity. The results suggested that polyphenols and 5-hydroxymethylfurfural were important factors influencing the antioxidant capacity of vinegars.