Determination of some biochemical properties of grape varieties grown in Hizan (Bitlis) provi̇nce

This study was carried out to determine the biochemical properties of 19 local grape varieties grown in the Hizan (Bitlis) province. The cluster and berry characteristics, total phenolic compounds, total flavonoids, total monomeric anthocyanins, vitamin C, individual phenolic compound contents, antioxidant activities of the grape varieties, were determined. It was found that total phenolic compound contents of grape varieties ranged from 96.30 to 529.53 mg GAE g-1 FW, total flavonoid contents ranged from 48.70 to 343.80 mg QE g-1 FW, total monomeric anthocyanin contents ranged from 0.86 to 10.85 mg cyanidin 3-glucoside g-1 FW, total antioxidant activity capacities ranged from 4.19 to 28.19 mmol TE g-1 FW according to the DPPH method, from 1.64 to 28.23 mmol TE g-1 FW according to the FRAP method and vitamin C contents ranged from 7.06 to 25.13 mg 100 g-1. In the examined varieties, (+)-catechin and p-hydroxybenzoic acid were identified as the most abundant individual phenolic compounds. It was determined that the according to individual phenolic contents, rihest varieties were the Bağılti in p-coumaric acid content; the Siyah Güzane in aminobenzoic acid, protocatechuic acid, and caffeic acid contents; the Tilka Pire in (-) epicatechin content; the Beyaz Üzüm in (+) catechin content; the Beyaz Sinciri in p-hydroxybenzoic acid content; and the Alaki in chlorogenic acid content. According to the cluster analysis results, Kuş Üzümü and Siyah Güzane varieties had the highest must pH, total phenolic compound, total flavonoid substance, aminobenzoic acid, protocatechin acid, (-) epicatechin, caffeic acid, chlorogenic acid and (+) catechin values compared to other varieties.