Dissipation of Fungicide Residues during Winemaking and Their Effects on Fermentation and the Volatile Composition of Wines

The effects of four fungicides commonly used for the control of fungal diseases in vines and grapes in the course of winemaking were tested. The concentration of fungicide residues was monitored throughout the process to establish their kinetics of dissipation. In all cases the percentages of dissipation were >68%, which shows the detoxificant effect of the winemaking process. On the other hand, the effect of the fungicide residues on the aroma composition of Tempranillo red wines was tested. To evaluate possible modifications on the aroma profile of wines, seven odorant series (ripe fruits, fresh fruits, lactic, floral, spicy, vinous, and herbaceous) were built from the odor activity values (OAVs) obtained for each volatile compound. Ripe fruits and fresh fruits were the major aromatic attributes in all Tempranillo red wines. These two odorant series registered the highest variations in their total OAVs with respect to the control wine, especially with the application of boscalid + kresoxim-methyl into vines, leading to a decrease in the ripe fruit and fresh fruit nuances of the resulting wines. Moreover, when the effect of these fungicides on the aroma of Tempranillo red wines was compared throughout two years (2012 and 2013), wines elaborated from grapes treated in the field with boscalid + kresoxim-methyl in 2013 displayed the highest variation in aroma profile with respect to control wine.