The study of antioxidants in grapevine seeds

Grapevine seeds contain a large amount of antioxidant components, and are therefore recommended in the prevention and treatment of many diseases. For this research, we studied the antioxidant properties of grapevine seeds from the Marlen variety, as evidence suggests that these types have higher resistance against fungal diseases. Through high-performance liquid chromatography with UV/VIS detection, a total of 10 antioxidant components were selected for further investigation, specifically: catechin, epicatechin, rutin, quercitrin, quercetin, caftaric acid, caffeic acid, p-coumaric acid, ferulic acid, and gallic acid. The antioxidant activity was determinated spectrophotometrically through the adoption of three fundamentally different methods (the DPPH assay, the ABTS method, and the FRAP method). Using the Folin-Ciocalteu method, it was possible to determine the content of all the polyphenolic compounds. The results of the assessment antioxidant activity and the content of polyphenolic compounds were recalculated to gallic acid equivalents (GAE). The values of the antioxidant activity as determinated by the DPPH test were 6643 (+-154) mg of GAE; 1984 (+-88) mg of GAE when using the FRAP method; and 812 (+-31) mg of GAE when the ABTS method was utilised. The content of the total polyphenolic compounds came to 6982 (+-221) mg of GAE. The most abundant antioxidant was catechin, with a content of 115 mg.L-1, whilst the least represented compound was ferulic acid (0.139 mg.L-1). Overall, this study showed a high antioxidant potential of grapevine seeds.