EFFECT OF THERMAL TREATMENT IN POTENTIAL PHENOLIC OF GRAPES AND WINES

The aim of these research was to determine the effect of thermal treatment in industrial and phenolic ripening of grapes and phenolic composition of wines at 1 and 12 months of storage. The experiments were conducted in 2013/14 harvest in vineyards with Tannat and Cabernet Sauvignon varieties of Dom Pedrito, RS, as experiment 1 and 2, respectively. Each vineyard has been divided into two blocks for treatments: control and thermal (Thermal Pest Control - TPC). In experiment 1, TPC treatment reduces total acidity and content of total polyphenols in grapes. Already in wine, no changes were observed in levels of total polyphenols, procyanidins and monomeric anthocyanins. In experiment 2, the TPC stimulated total polyphenol index and reduced the bark tannins in grapes, without changing wine composition. Therefore, using the TPC field of heat treatment on grapevines can induce secondary metabolism in response grapes, wine however was only observed in the effect of elicitor intensity of color.