Analysis and identification of the main monomeric phenolic compounds and an estimation of antioxidant activity in appellation of origgin Greek red wine

2000

Subashi, N.

Twenty-nine red wines produced according to the Greek appellation of origin system were selected to provide a range of production area and grape varietes. Sensitive and selective HPLC methods were used for the analysis of the major phenolics in these wines: gallic acid, (+)-catechin, (-)-epicatechin, syringic acid, cinnamic acid, caffeic acid, p-coumaric acid, ferulic acid, rutin, myricetin, quercetin, kaempherol, p-OH-benzoic acid, protocatechuic acid, vanillic acid; trans-resveratrol and anthocyanin monoglucosides (delphenidin-3-glucoside, cyanidin-3-glucoside, petunidin-3-glucoside, peonidin-3-glucoside and malvidin-3-glucoside). The 29 wines exhibited a wide concentration range of all parameters investigated. Regarding phenolic acids, gallic acid was the most abundant in all samples examined (average 35.7 mg/L). As far as flavonols are concerned, quercetin was found to be the most abudant compounds (average 4.3 mg/L). In addition, the analysis of the individual anthocyanin monoglucosides demostrated malvidin being the highest anthocyamin present (average 5.22mg/L). Moreover, trans-resveratrol average concentration was 1.139 mg/L. The content of total phenolics in the wine was determined according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). It averaged 2746.62+-0.80 mg/L. Antioxidant activity of red wine samples was evaluated spectrophotometrically by coupled oxidation of Ö-carotene and linoleic acid. Each wine was characterized by an antioxidant activity expressed as the percent of inhibition relative to the control (AA per cent) ranging from 13.9 per cent to 71.64 per cent. In addition, antioxidant activity was expressed as oxidation rate ratio (ORR) ranging from 0.861 to 0.284

2003/QC/QC2003_0.rdf