Influence of Vinification Practices on the Elements Concentration in Vranec wines studied by ICP-OES

The presence of metals (i.e. Al, Zn, Cu, Fe, Pb) in wine is important for efficient alcoholic fermentation and for its sensorial characteristics (flavor, aroma, freshness). Certain metal ions, such as Fe, Cu and Mn participate in destabilization of wine and in their oxidative evolution, whereas Cu, Fe, Al, Zn and Ni contribute to haze formation and undesirable changes of aroma and taste. The element composition of the wines may be influenced by many factors such as elemental levels in the soil, fertilization practices, wine processing equipment and vinification [1,2]. In this study, Vranec wines produced with different maceration times (4, 7, 14 and 30 days) in presence of enzyme and oak chips during fermentation were studied in order to determine the influence of vinification conditions on the elements concentration. Analysis was performed with inductively coupled plasma – optical emission spectrometry (ICP-OES) for accurate determination of the concentration of 18 elements (Al, Ba, Bi, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, S, Sr, V, Zn). The results demonstrate that Mg and P increased during maceration, while the other elements content was not affected by the maceration time duration. Wines macerated for 7, 14 and 40 days, fermented in presence of oak chips showed highest content of Al, Ba, Fe, K, Mn, and P. The Student–Newman–Keuls test was applied to ascertain possible significant differences between the studied wines, and factor analysis was employed showing separation of the wines mainly according to the oak chips treatment