Analytical determination of Dolenjska region wines quality

We monitored the levels of pesticide residues (GC-MS and LC-MS-MS), copper (FAAS), biogenic amines (HPLC-DAD), volatile phenols (SBSE-GC-MS) and microbiological quality (membrane filtration) in bottled Cviček and Blaufränkisch wines in two consecutive years. In bottled Cviček wines of 2008 and 2009 vintages sampled at the producers, residues of eight and twelve pesticides were determined respectively. Consequently, the producers should make an attempt to reduce the number of pesticide residues in wines. The most frequently determined pesticides were fenhexamid, cyprodinil, metalaxyl-M, iprovalicarb, dimethomorph, fludioxonil and pyrimethanil. The concentrations of pesticide residues in samples did not exceed the proposed maximum residue limits (MRLs). The highest concentration in 2008 was determined for iprovalicarb (0.20 mg L−1) and in 2009 for fenhexamid (0.31 mg L−1). Copper levels in the Cviček wines were definitely too high and 17 samples in 2008 and seven in 2009 exceeded the MRL. The microbiological stability of the wines was poor and should be improved. However, the levels of biogenic amines in the traded Cviček and Blaufränkisch wines were low. Furthermore, we only detected 4-ethylguaiacol and 4-ethylphenol above the LOQ (limit of quantification) in three Blaufränkisch wines in concentrations of 81-152 μg L−1 and 149-435 μg L−1. These results together with Brettanomyces spp. yeast detection in two Cviček wines signify that producers should pay more attention to the both issues.

► The producers should make an attempt to reduce the number of pesticide residues in wines. ► The concentrations of pesticide residues in samples did not exceed the proposed MRL. ► Copper levels in the Cviček wines were too high. ► The microbiological stability of the wines was poor and should be improved. ► The levels of biogenic amines and volatile phenols in the traded Cviček and Blaufränkisch wines were rather low.