Heavy metal (Pb, Cu, Zn and Cd) content in wine produced from grape cultivar Mavrud, grown in an industrially polluted region
Abstract
The investigation was carried out in the period 1991-1993 with cv. Mavrud, grown in the region with a major industrial pollutant the Non-Ferrous-Metal Works (NFMW) and a region with no industrial pollutants (as a control). The heavy metal content in soil, grapes and wine was determined. Most of the heavy metals in the grapes precipitate during fermentation into the sediments, which is the reason for their significantly lower content in the wine. Water washing of grape before processing leads to about 2 time decrease in the Pb, Cu, Zn and Cd contents of wine. The pre-washing of grapes does not lead to any quality deterioration in the wine produced. The amounts of Cu, Zn and Cd in the wine from cv. Mavrud, grown in the region of the NFMW-Plovdiv, are lower than the maximum admissible levels, while the Pb content exceeds them about two times.