Pesticide residues and microbiological quality of bottled wines

In the study we determined the pesticide residues and microbiological quality of bottled wines. Pesticide residues in wine were analysed using the multiresidual method with GC–MS, the multiresidual method with LC–MS–MS and the method for determination of dithiocarbamate residues with GC–MS. Furthermore, the effect of bentonite and the combined fining agent on the concentration of boscalid in wine was tested. The microbiological analysis was performed using membrane filtration. Nine pesticide residues were determined in the samples. More than 50% of wines belonged to the category of wines with only up to two pesticide residues. The most frequently determined pesticide in wines was boscalid (76% of samples) followed by fenhexamid (44%). The highest concentrations of pesticide residues in wines were determined for cyprodinil (0.44 mg/L) and fludioxonil (0.21 mg/L). The combined fining agent was more efficient in lowering the concentration of boscalid in wine if compared with bentonite. The results of microbiological quality indicate that no less than one quarter of bottled wines on our store shelves is microbiologically unstable.