Evaluation of the effect of fungicide formulations of mepanipyrim (50 % w/w) and tetraconazole (12.5 % w/w) on the volatilome of Saccharomyces cerevisiae EC1118™ during the winemaking of Airén grapes

The present study investigates the impact of the commercial formulations of mepanipyrim and tetraconazole on the volatile composition and aromatic profile of Airén white wines inoculated with Saccharomyces cerevisiae EC1118™ yeasts. Fungicides were added separately to the grape must at concentrations equivalent to 2 mg/kg mepanipyrim and 0.5 mg/kg tetraconazole, respectively. In addition, a control fermentation (without fungicides) was done for comparative purposes. Subsequent to the culmination of the winemaking process, the wines thus obtained were characterised in accordance with their oenological parameters and aromatic composition.

The results of this study demonstrated that both fungicides were reduced by 84 % during the winemaking process. Moreover, the presence of both fungicides resulted in a slight alteration to yeast activity, with a concomitant effect on certain fermentation parameters (total and free sulphur dioxide content, and volatile acidity), particularly when the tetraconazole-based formulation is employed. Furthermore, it was determined that both commercial formulations have a significant effect on the aromatic composition of the wine, with this effect being more pronounced when the mepanipyrim-based formulation was added. The application of this fungicide resulted in an increase in the content of monoterpenes, C₁₃-norisoprenoids, C₅/C₆-alcohols, fatty acids, and lactones. Consequently, treated wines exhibited a greater overall olfactory intensity, with a greater prevalence of notes associated with ripe fruit.