Determination of polyphenols content and antioxidant activity of some red wines by differential pulse voltammetry, HPLC and spectrophotometric methods

Red wines produced in three different wine growing regions of Croatia were analysed for total polyphenols (TP) content, concentration of individual polyphenols and antioxidant activity (AA). TP content was measured by differential pulse voltammetry (DPV), Folin–Ciocalteu (FC) and HPLC methods. Individual polyphenols were measured by HPLC and AA was determined by ABTS and DPPH methods. The results showed that DPV is a very sensitive method for the determination of TP. A very high correlation was obtained between the TP content determined by DPV, FC and HPLC. The major polyphenols in the wines were gallic acid and (+)-catechin. TP, individual polyphenols and AA varied among wines from different regions. Wines from the Dalmatia region had the highest TP content, the highest concentration of important antioxidants and significantly higher AA. There was a very high correlation between AA and TP in all of the wines tested.