Anthocyanin composition of Vranec, Cabernet Sauvignon, Merlot and Pinot Noir grapes as indicator of their varietal differentiation.

摘要

The anthocyanin composition of red grape varieties Vranec, Cabernet Sauvignon, Merlot and Pinot Noir was determined analyzing the skin extracts of the grape berries. The relative content of the identified anthocyanins was calculated and the obtained anthocyanic profiles were compared in terms of acylation and anthocyanidin distribution. The predominant anthocyanin in all varieties was malvidin-3-glucoside ranging from 35.8% in Cabernet Sauvignon to 67.1% in Pinot Noir. Vranec variety was characterized by high proportions of coumaroyl derivatives (22%) and peonidins (13%). The most pronounced difference among the studied grape cultivars was the relative amount of acetate derivatives accounting 35% in Cabernet Sauvignon, 22% in Merlot and 9% in Vranec. Different relationships among the anthocyanin groups of compounds were calculated and considered as parameters for differentiation of the cultivars. The relationship between coumarates and acetates in Vranec was significantly higher compared with Merlot and Cabernet Sauvignon with obtained values of 2.37 versus 0.63 and 0.56, respectively. Moreover, the ratio between delphinidins and peonidins allows clear discrimination between the studied grape cultivars showing the greatest difference.