ANTHOCYANIN COMPOSITION OF TANNAT, CABERNET SAUVIGNON AND MERLOT GRAPES AND RED WINES: UTILITY OF THE PROFILES OBTAINED FOR THE VARIETAL CHARACTERISATION

The anthocyanic composition of Tannat, Cabernet Sauvignon and Merlot red grapes and wines was studied in 2002 and 2003. The vineyards were located in the South of Uruguay, consisting of 4 Merlot, 4 Cabernet Sauvignon and 3 Tannat. Grape samples were taken in the harvest, and kept frozen at -20 °C until they were analysed. For this purpose, the skins were separated and macerated in a 12 % ethanol and pH 3.2 solution for 24 hours, with two repetitions per vineyard. The extracts obtained were analysed by HPLC and their anthocyanic composition was determined. Vinifications were carried out with 50 kg of grapes and two repetitions per vineyard. The anthocyanic contents of the wines were analysed two months after the alcoholic fermentation had finished. Grapes and wines of each variety presented contents and anthocyanic profiles statistically different. Tannat skins and wines showed anthocyanic contents significantly higher. Delphinidin, petunidin and non-acylated glucosides proportions were significantly higher in the skins and in Tannat wines. Malvidin and acetate proportions were significantly higher in Cabernet Sauvignon grapes and wines. The consideration of the anthocyanic profiles allowed the discrimination of all the grapes and wines samples of each variety. The relation between the acetyl and coumarylic forms allowed the differentiation of Cabernet Sauvignon grapes and wines from Merlot and Tannat, but not these between themselves. We recommend that you consult the full text of this article, which was published in Bulletin de l'O.I.V. 2005, 78 (887-888) 30-44. Original title: Estudio de la composición antociánica de uvas y vinos tintos de los cv. Tannat, Cabernet Sauvignon y Merlot: utilidad de los perfiles obtenidos para la caracterización varietal