Evolution of residual levels of six pesticides during elaboration of red wines. Effect of wine-making procedures in their disappearance

The effect of wine-making procedures on the concentrations of six pesticides (chlorpyrifos, penconazole, fenarimol, vinclozolin, metalaxyl, and mancozeb) in red wines has been studied. During maceration stage (4 days), the percentage remaining of chlorpyrifos, penconazole, and metalaxyl was similar to 90%, whereas that of fenarimol, vinclozolin, and mancozeb is somewhat smaller (74-67%). The residual levels found in pressed must were less than or equal to 20%, except for metalaxyl (69%). From the whole concentration of chlorpyrifos in must, 85% is eliminated from the racking step; clarification (bentonite plus gelatin) eliminates 43% of the product found in the decanted wine, and with filtration, all of the residue is eliminated. Penconazole and mancozeb are retained on the lees in proportions of 43 and. 31%, respectively. The eliminated percentage of vinclozolin after racking is 29%, whereas clarification and filtration reduce its proportion in the wine to 33 and 28%, respectively. Finally, fenarimol and metalaxyl are eliminated in smaller proportion with the realization of these processes.