Application of new fungicides under good agricultural practices and their effects on the volatile profile of white wines

Three new commercial fungicides to control downy mildew (Plasmopara viticola), which contain new generation fungicides (benalaxyl, iprovalicarb and piraclostrobin) were applied under Good Agricultural Practices (GAP) in an experimental vineyard producing white grapes (Vitis vinifera) Godello var. Once white grapes were harvested, single vinifications were performed. To evaluate possible modifications in aroma composition of wines, Odour Activity Values (OAVs) were estimated due to this parameter provides information about sensorial changes. Fungicide residual levels found in treated wines with respect to the control wine reduced the varietal aroma of wines attributed to geraniol. However, treated wines showed an increase in the fruity aroma due to several ethyl esters (ethyl hexanoate, ethyl octanoate, and ethyl decanoate) and acetates (3-methyl-1-butyl acetate and 2-phenylethyl acetate) increased their levels and OAVs in presence of fungicide residues; these secondary products of the fermentation process influence strongly the aromatic profile of young wines.