Varietal differences among berry composition of three Croatian red grape cultivars during ripening

The quality of red wines depends on precise harvest date that is linked with ripeness of pulp, and skin and seeds. The concentration of phenolic compounds from grape skin and seeds and their extractability during maceration is directly linked to color and flavor of wine but their content vary greatly depending on the grape cultivar, ripening stage and other environmental effects. This study was done to evaluate the dynamics of physiochemical variables of berries during last stage of ripening from the major red Croatian cultivar ‘Plavac Mali’ and two less known and almost neglected cultivars, ‘Dobricic’, and ‘Ljutun’. The chemical composition of berries and surface color of the skin (CIELab parameters) have been analyzed at four different sampling dates. A significant varietal variability was observed for most common maturity indices (total soluble solids, total acidity, pH, single berry weight), whereas some parameters such as total colorimetric value (CIRG) derived from the color evaluation showed linear progression over the sampling dates. Total anthocyanins and total phenols concentrations increased during ripening, while significant differences among cultivars were observed. ‘Ljutun’ showed significantly the highest content of total acidity and the smallest content of total soluble solids in comparison to other two cultivars suggesting its good potential to improve ‘Plavac Mali’ and ‘Dobricic’ wines by blending in the vineyard. The results of berry composition during the four different ripening stages for ‘Plavac Mali’, ‘Dobricic’ and ‘Ljutun’ indicated that choosing the optimal harvest date is important for wine quality.