Total antioxidant activities, phenolics, anthocyanins, polyphenoloxidase activities and its correlation of some important red wine grape varieties which are grown in Turkey

Eight important red wine grape varieties (Alicante, Kuntra Karasakiz, İrikara, Gabarnet Franch, Cinsaut, Gamay, Merlot and Syrah) which are use for production for red wine by Doluca winery were analyzed. The highest AA (percentage of inhibition on peroxidation in linoleic acid system) was obtained in Gabarnet Franch and Merlot extracts as 90.25% and 90.15% respectively. The lowest AA was determined in İrikara (83.20%) which had the lowest phenol content. Total phenol content (TP) was varied between 1376 (İrikara) and 2329 µg × ml-1 GAE equivalent in methanol extracts (Merlot). Total anthocyanin content (TA) was ranged from 253.5 mg × kg-1 (İrikara) to 2488.4 mg × kg-1 (Alicante). The lowest PPO activity was found in Merlot (0.070 U × ml-1 × min) and the highest activity in Gamay (1.155 U × ml-1 × min). Total sugar content in the analyzed varieties was changed from 15.30% (Syrah) to 22.64 (Merlot). The examinations showed that AA and TP significant correlation (r2 = 0.854**) but less significantly related with TA (r2 = 0.263).