Antioxidant constituents and antioxidant activity of some red wine and red table grape varieties, cultivated in diff erent regions of Bulgaria

Milena Tzanova, Vasil Atanasov, Miroslav Ivanov, Anatoli Iliev, Stefka Atanassova, Penka Peeva, Neli Grozeva, Maria Gerdzhikova,

Abstract: Foods that have a positive effect on human health are becoming more and more popular nowadays. Such foods are the grapes - rich in phenolic compounds, which are known as very potent bio-antioxidants. This paper presented a research made for the first time - twelve red wine varieties (Rubin, Kaylashki Rubin, Storgozia, Mavrud, Nikopolski Mavrud, Melnik 55, Bouquet, Cabernet Sauvignon, Merlot, Syrah, Mourvedre and Malbec) and eight red table varieties (Velika, Dunav, Siyana, Hybrid V5-1, Muskat Hamburg, Moldova, Palieri and Black Pearl), cultivated in different regions of Bulgaria were tested for their antioxidant activity (AA) and contents of total phenols (TPC), trans-resveratrol (t-RVT) and quercetin (QU). In the grape skins the parameters ranged: t-RVT- from 2.05 ± 0.21 to 14.34 ± 1.35 and from 1.44 ± 0.17 to 23.71 ± 2.53 mg/kg FW; QU - from 0.27 ± 0.03 to 1.98 ± 0.18 and from 0.63 ± 0.07 to 2.12 ± 0.20 mg/kg FW; TPC – from 17 ± 2 to 371 ± 33 and from 21 ± 2 to 444 ± 43 mmol GAE/kg dm and AA – from 23.2 ± 1.9 to 59.9 ± 5.5 and from 32.4 ± 2.8 to 66.4 ± 6.3 mmol TE/kg dm for wine and table grapes, respectively. The table grape varieties had higher mean values of the parameters examined than the wine grape varieties. South Bulgaria have grape varieties with higher values of the antioxidant parameters with comparison to North Bulgaria. But, Danubian region, North Bulgaria, have wine and table grape varieties with very good antioxidant parameters and can‘t be ignored. The reason for this is the agrometeorological conditions. The correlations between the determined values were positive with very high correlation coefficients.

Keywords: antioxidant activity; quercetin; table grapes; total phenols, Trans-resveratrol; wine grapes

Date published: 2019-12-29