POLYPHENOLS, ANTHOCYANINS CONTENT RELATED TO COLOUR CHARACTERISTICS OF WINE AND GRAPE JUICE INCLUDING OTHELLO HYBRID.

Polyphenols are the main contributors for the wines color and also for others characteristics of wines such as astringency and bitterness. Samples of wines (red and white) were analyzed following to assess their polyphenols and anthocyanin's content in relation with their color characteristics. The properties of red (Fetească Neagră) and white wines (Fetească Albă from Cotnari vineyard) were compared to the wine made of grape hybrid cultivar Othello. Also the grape must obtained of hybrid cultivar Othello was analyzed. Polyphenols and anthocyanins were assessed by UV-VIS spectrophotometric methods. Polyphenols content was analyzed using Folin-Ciocalteu method and was expressed as gallic acid. Calibration with gallic acid as standard polyphenolic substance was previously performed. The method for determining anthocyanins is based on their property to be discolored by sulfites. Permanganate index was also determined to evaluate the reducing characteristics of wines by titration against potassium permanganate in the presence of Indigo carmine as redox indicator. Glories chromatic parameters such as color intensity, tonality, %Yellow, %Red and %Blue were established. Polyphenol of the analyzed wines ranged between 47-2653 mg/L polyphenols while the anthocyanins were 0-245 mg/L. Permanganate index was in the range of 14-87 ml KMnO4/L. The polyphenols content of the wine made of hybrid cultivar Othello was lower than that of red wine (Fetească Neagră). The color intensity was significant lower than that of Feteasca Neagră wines. [ABSTRACT FROM AUTHOR]