Comparison Between Sensory and Nephelometric Evaluations of Tannin Fractions Obtained by Ultrafiltration of Red Wines

Introduction Although the assessment of red wine quality relies primarily on a sensory description of tannins, it may be usefully completed by some knowledge of the physicochemical properties of these tannins. The present study has a double aim: (1) to gain insight into the sensory properties of subpopulations of proanthocyanidic tannins of different molecular sizes (obtained through several ultrafiltration steps), as well as into the kinetics of the haze formed by these fractions when reacted with polyvinylpyrrolidone (as measured by nephelometry) and (2) to determine whether a correlation exists between the sensory and the nephelometric data.