STUDIES ON THE CHROMATIC CHARACTERISTICS OF RED WINES AND COLOR EVOLUTION DURING MATURATION

The chromatic profile of red wines are formed by the participation of various compounds phenolic: anthocyanins, tannins, flavones and phenolic acids, anthocyanins are polyphenolic substances with the most imported role in the color of young wines. The evolution of red wine leads to changes of structures and chromatic properties of wine due to polymerization reactions, condensation and oxidation. Also the red wine color is strongly influenced by wine region of origin, the wine grape variety and vintage year. There were studied chromatic characteristics of red wines as Merlot and Feteasca Neagra from two different vineyards in terms ecopedoclimatics, Dobrogea and Moldova, the 2008 year harvest. The polyphenolic composition of wines was judged by the content in polyphenols, tannins and anthocyanins. A wine tannin structure was analyzed by their concentration in condensed tannins, astringent tannins and tanninpolysaccharide complex. Analyzes have been carried out in the wine by UV-VIS spectrometry techniques. Total content of polyphenols have been determined by IPT technique. Tannins have been determined by the Ribereau-Gayon method (1996), tannin structure after Glories (1978) method; anthocyanins were determined by the discoloration technique with SO2. Color intensity was determined at �� =420 nm and �� =520 nm. The study on color of red wines analyzed during their evolution referred to the study of chromatic parameters, the content of anthocyanin monomers and polymers (Glories method).