STABILITY IN WINE DIFFERENTIATION OF 2 CLOSE VITICULTURAL ZONES

Pattern recognition techniques were applied to the discrimination of w ines from two very close viticultural regions. They are two zones in t he Utiel-Requena region (Valencia, Spain) of Certified Origin centered in the Utiel and Requena towns, respectively. The differentiation is due to various climatic factors, since soil characteristics are very s imilar and the cultivars are the same. This climatic differences influ ence the degree of ripeness attained The differences in altitude of th e zones account for their climatic differences. This study focused on data corresponding to rose wines (Bobal cultivar) from the 1988 vintag e. Discriminant analysis showed that four variables (ethanol, anthocya nins, K, and Na) allowed a satisfactory zone classification of these r ose wines (93.5% well classified). The application of the discriminant analysis results to a series of wines of the same year, not considere d previously, has also led to successful results (90.6% well classifie d). In order to evaluate the discriminant power of these variables, th e study was broadened to include a longer period (1987-1994). In each case, the analysis was similar although data used were only those corr esponding to the four variables above-mentioned. In all cases, the cla ssification was acceptable (90.7% well classified on average and bette r than 81% in each individual case), thus showing the stability of the discriminant variables along a period of eight years. The influence o f the climate (year) is demonstrated through the variation of the disc riminant variables coefficients.