Polyphenolic composition of seeds from native Greek grape varieties: association with antiradical activity
2004
Guendez, R.
Ethyl acetate extracts from seeds originating from nine Hellenic native and international V. vinifera varieties cultivated in Greece were screened for their content in characteristic polyphenolic components. The compounds determined were principal constituents of low molecular weight, including Gallic acid (GA), Catechin (CT), Epicatechin (ECT), Epigallocatechin gallate (EGCG), and Procyanidins B1 and B2 (dimmers). Total content varied from 55.10 to 963.88 mg per 100 g of seeds, the average being 379.61 mg per 100. The most abundant polyphenol was CT, accounting for 49.8 percent of the total content, followed by ECT(26.0 percent), ECG (9.3 percent), procyanidin B1 (5.8 percent) and procyanidin B2 (5.1 percent) whereas EGC and GA were minor constituents. The assessment of the in vitro antiradical activity (Aar) employing the stable radical DPPH showed that there was a significant correlation with total polyphenol content determined using thew Folin-Ciocalteu method (r sup(2) = 0.6499, P 0.01). The correlations with the individual compounds, however, revealed that procyanidin B1 may be on the most important radical scavengers in grape seed extracts (2 sup(2)
显示更多 [+] 显示较少 [-]