Phenolic compounds in grape bunch and wine of Georgian autochthonal vine variety Tsolikauri

The objective of the study was to determine qualitative composition and quantitative content of phenolic compounds in grape bunch (stem, grape skin, seeds) and wine of Georgian autochthonal vine variety Tsolikauri by high-performance liquid chromatography (HPLC). Tsolikauri bunch stem contains the following phenolic compounds: gallic acid (0.096 mg/g), protocatechuic acid (0.071 mg/g), (+)-catechin (0.021 mg/g), caffeic acid (0.026 mg/g), (-)-epicatechin (0.007mg/g), rutin (0.112 mg/g) and quercetin (0.064 mg/g); trace quantities of vannilic acid, dihydroquercetin, o-coumaric acid. Syringic acid, ferulic acid, resveratrol and p-hydroxybenzoic acid were not found. Content of phenolic compounds in the grape skins is the following: protocatechuic acid (0.037 mg/g), caffeic acid (0.005mg/g), (-)epicatechin (0.014 mg/g), rutin (0.149 mg/g) and p-hydroxybenzoic acid (0.063 mg/g); trace quantities of (+)-catechin, vannilic acid and o-coumaric acid. Gallic acids, syringic acid, ferulic acid, dihydroquercetin, resveratrol, quercetin were not found. Phenolic compounds content in the grape seeds is the following: gallic acid (0.535 mg/g), protocatechuic acid (0.212 mg/g), (+)-catechin (3.131 mg/g), syringic acid (0.313 mg/g), (-)-epicatechin (0.211 mg/g), ferulic acid (0.02 mg/g) and quercetin (0.102 mg/g); trace quantities of vanilic acid and o-coumaric acid. Caffeic acid, dihydroquercetin, rutin, resveratrol, phydroxybenzoic acid were not found. Phenolic compounds of Tsolikauri wine are: gallic acid (23.287 mg/ l), protocatechuic acid (10.33 mg/l), (+)-catechin (23.987 mg/l), caffeic acid (0.616 mg/l), syringic acids (1.591mg/l), (-)-epicatechin (1.13 mg/l), dihydroquercetin (0.556) mg/l), rutin (9.103 mg/l) and quercetin (1.629 mg/l); trace quantities of vannilic acid, ferulic acid and o-coumaric acid. Resveratrol and phydroxybenzoic acid were not found.