Comparison of Eleven Commercial Grape (Vitis vinifera L.) Cultivars in Terms of Phenolics Profiles and Antioxidant Properties

Grapes are one of the richest sources of different phenolic compounds with high antioxidant, antibacterial and nutritional properties among fruits. The aim of this study was to investigate the different classes of phenolic including flavonols, flavanols, flavone, anthocyanins, stilbenes and phenolic acids in eleven Vitis vinifera cultivars. Based on the result, the highest catechin, epicatechin, ferulic acid and chlorogenic acid was related to ‘Yaghooti’ grape cultivar. However, catechin gallat, kaempferol, myricetin and p-coumaric acid of ‘Bidaneh Ghermez’ showed a higher content (p < 0.05) compared to other cultivars. Berry quercetin (as main flavonols) was found to be highest (9.48 μg g-1; p < 0.05) in ‘Yaghooti’ . The berry skin luteolin as a flavone ranged from 0.49 μmol g-1 in ‘Rishbaba’ to 0.88 μmol g-1 in ‘Bidaneh Ghermez’ cultivar. The content of delphinidin-3-glucoside and malvidin-3-glucoside of ‘Yaghooti’, cyanidin-3-glucoside and peonidin-3-glucoside of ‘Angoor Siah’ and petunidin 3-glucoside of ‘Bidaneh Ghermez’ was found to be higher (p < 0.05) compared to other cultivars. Berry resveratrol varied from 22.7 μg g-1 in ‘Monaqa and Fakhri’ cultivars to 54.8 μg g-1 FW in ‘Bidaneh Ghermez’ with an overall average of 36.9 μg g-1 FW. Among different cultivars, the antioxidant capacity of ‘Angoor Siah’ was the highest (71.3%; p < 0.05) and ‘Monaqa’ was the lowest. Also, the ‘Angoor Siah’ cultivar has more antibacterial activity compared to other cultivars. Totally, the berry skin of ‘Yaghooti’, ‘Angoor Siah’ and ‘Bidaneh Ghermez’ showed the highest health promoting bioactive compounds, which could be considered further in future studies.