Caracterització fenòlica i aromàtica de la garnatxa negra a la denominació d'origen Montsant. Estratègies enològiques per a la millora del color

Abstract

The evolution of consumer tastes and the demands of international markets lead winemakers to produce structured wines with intense colours. To improve the colour of Grenache Noir wines, oenological strategies must be implemented to maximize the presence of phenolic compounds in grapes and to develop the most appropriate ways of harnessing the phenolic potential of the variety. Grenache Noir is a variety with large amount of tannins, so advantage may be taken of its phenolic potential to make available to the anthocyanins the highest possible concentration of tannins, thus facilitating their union and stabilizing the wine. However, it is difficult to achieve simultaneously high concentrations of the two compounds in the must. Anthocyanins and tannins are extracted in different maceration times: while anthocyanins are removable in water, it is difficult to extract tannins without the presence of alcohol and high temperatures. The aim of this study was to test the efficiency, in both an analytical and sensory way, of different winemaking techniques for improving the colour of Grenache Noir wines from Montsant. To conduct the study, vinifications were carried out in three consecutive vintages (2011, 2012 and 2013). The evolution of tannin concentration, of the total polyphenols index and of the free and total anthocyanins index during vinification was studied. The basic chemical, phenolic and aromatic characterization and a sensory analysis by a tasting panel were carried out on the resulting wine.