Characterisation of Vranec, Cabernet Sauvignon and Merlot wines based on their chromatic and anthocyanin profiles

Wines of three different grape varieties, Vranec, Cabernet Sauvignon and Merlot, were characterised in terms of their anthocyanin and chromatic profiles, total polyphenols and antioxidant potential. The total, monomeric, polymeric and co-pigmented anthocyanins were determined by spectrophotometry and the individual anthocyanin compounds were quantified using HPLC DAD. The chromatic profile was evaluated according to colour density, hue, % red, % blue, % yellow and brilliance (dA). The established data were submitted to analysis of variance and principle component analysis in order to evaluate their potential for differentiation of wines according to variety and vintage. The Vranec wines showed distinctive characteristics, with the highest content of anthocyanins and values of colour intensity, % red and dA, compared to the other two studied varieties. The content of petunidin-3-glucoside, peonindin-3-glucoside and anthocyanin acetates were established as possible markers for the differentiation of Vranec wines from Cabernet Sauvignon and Merlot wines. However, none of the assayed parameters could be used for the differentiation of Cabernet Sauvignon from Merlot wines. It was observed that wine age limits the successful classification of the wines by variety according to anthocyanins. The chromatic parameters allowed young (aged up to 1 year) to be distinguished from old Vranec wines.