Potravinarstvo (Nov 2014)
Evaluation of influence of the locality, the vintage year, wine variety and fermentation process on volume of cooper and lead in wine
Abstract
We have focused on the influence evaluation of the locality, the vintage year and fermentation process on the volume of copper and lead into grape must and wine. First of all copper and lead volume was assessed into fresh grape musts. Subsequently the musts were fermented. During the wines analyses we found great decrease of copper by the fermentation process. Assessed Cu2+ values vary from 0.07 to 0.2 mg.L-1 and represent a decrease of the original copper volume from 90 to 97%. On the copper content into grape has probably the significant influence also the precipitation amount, which falling in the second part of the vegetation half a year. Total rainfall in the period before the grape harvesting (the months of August - September) was for the first year 153 mm and for second year 137,5 mm. During both observed vintage years it was concerning to the above average values. Copper is not possible to eliminate totally in the protection of the vine against fungal diseases, because against it does not come into existence resistance into a pathogen. For resolution of this problem it is suitable to combine the copper and organic products. Fermentation affect as a biological filter and influence also lead volume. Into analysed wines we found the decrease of the lead volume from 25 to 94%. Maximal assessed Pb2+ value into wine was 0.09 mg.L-1. The linear relationship between lead and copper into grape must in relationship to the lead and copper into wine was not statistically demonstrated. We found the statistically significant relationship in lead content into grape must by the influence of the vintage year, which as we supposed, it was connected with the atmospheric precipitation quantity and distribution during the vegetation. On the base of the assessed results of the lead and copper volume into wine, we state that by using of the faultless material and appropriate technological equipment during the wine production, it is possible to eliminate almost completely the problems with these heavy metals content into our wines and it is from the view of technological as well as hygienic.
Keywords
