Physicochemical characteristics, phenolic profile, and antioxidant capacity of Syrah tropical wines: effects of vineyard management practices

The present study evaluated the influence of training systems and rootstocks on the quality of Syrah tropical wines, produced at São Francisco Valley, Brazil. For this purpose, physicochemical characteristics, phenolic composition, and antioxidant activity were assessed in wines produced with grapes grown under divided trellis system (lyre) and esparlier or vertical shoot position (VSP) training systems, grafted on IAC 572, IAC 766 and Paulsen 1103 rootsotcks and harvested at two different periods. Harvest season had the strongest influence on wine quality, followed by the rootstock. Regardless of the training system and climatic variability between the harvests, the use of the IAC 766 rootstock led to wines with higher alcohol, anthocyanins contents and color intensity. The interaction between the espalier training system and the rootstock IAC 766 resulted in higher flavonol content, phenolic acids, and malvidin-3-O-glucoside, which was detected as the major phenolic as quantified by HPLC. This wine also presented significant levels of procyanidins A2 and B2, which showed a positive correlation with the antioxidant activity.