Variability of polyphenolic composition of quality red wines depending on the origin of raw material and winemaking conditions

Our studies refers to the influence of geographical origin of the raw material and the conditions of maceration and fermentation on the composition and extraction of polyphenolic complex at two of the most important varieties of high quality red wines from Romania, Cabernet Sauvignon and Feteasca Neagra; varieties come from different wine regions, Dealu Mare and Murfatlar, harvest of 2010. As regards the oenological practices, our studies aimed three variants of maceration and fermentation of the materials from the mentioned varieties, 5, 10 and 18 day. Analyzes have been carried out in the extracts from epicarp and in the resulted wine by UV-VIS spectrometry techniques. Total content of polyphenols have been determined by IPT technique. Tannins have been determined by the Ribereau-Gayon si Stonestreet method (1996), anthocyanins by dilution technique of the extract with a large amount of solvent (methanol) in strongly acidic conditions and in case of wines was used the discolouration technique with SO2. Color intensity and shade were determined at �� =420 nm and �� =520 nm. The results of the analyzes have shown significant differences concerning the polyphenolic complex content determined both of the origin of the raw materials as well as the technique used for maceration.