Antioxidant activity and phenolic content of wine vinegars produced by two different techniques

BACKGROUND: The presence of phenolics in fruit, red wine and vinegar has positive health effects due to their significant antioxidant activity. The aim of the study was to determine the effects of two different vinegar production methods on antioxidant activity and phenolic level of vinegars derived from Ulugbey Karasi grapes. Traditional surface and industrial submerge methods were used to make vinegar. Samples were taken from fresh red grape juice, maceration, wine, traditional vinegar and industrial vinegar. RESULTS: Total phenolic content of traditional and industrial vinegar samples were 2690 mg L-1 and 2461 mg L-1 GAE, respectively. ORAC values of traditional and industrial vinegar samples were 10.50 mu mol mL(-1) and 8.84 mu mol mL(-1) TE, respectively. Antioxidant activity values of traditional and industrial vinegars were 13.50 mmol L-1 and 10.37 mmol L-1 TEAC, respectively. Gallic acid, catechin, epicatechin, chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid and ferulic acid were detected in grape juice, wine and vinegar samples. The content of catechin in industrial vinegar (27.50 mg L-1) was significantly higher than that of in traditional vinegar (13.76 mg L-1) (P < 0.05). Traditional vinegar had higher amounts of chlorogenic and syringic acids than the industrial vinegar (P > 0.05). CONCLUSION: Results of this study showed that different production methods affected the functional constituents of wine vinegars. (C) 2010 Society of Chemical Industry