Title : Fractionation of essential and toxic elements in wines link toward geographical origin
Abstract:
Wine is one of the most widely consumed beverages in the world and the evaluation of its quality is important for manufacturers, merchants, and consumers. The confirmation of wine authenticity e.g. confirmation of its geographical and botanical origin is ? real analytical challenge. Various parameters including chemical elements content, their isotope ratios, particular organic constituents have been demonstrated as identifiers for wine authenticity. Evidently, the establishment of the profile of the chemical element of wine may reveal the geographical region and conditions of cultivation of grapes, as well as the manufacturing fabrications used. The hypothesis in this study is that total elements content in wine is not sufficient and changes in chemical speciation of elements during the vinification process present important information influencing the final evaluation of its geographical origin. In this study, the analytical procedure is developed for the determination of chemical elements contained in wine fractions – protein, polyphenol, polysaccharide as well as for the quantification of kinetically labile cation and anion complexes. As a first step the distribution of total Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hf, Li, Mn, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Sr, Ti, Th, Tl, U, V, W, Y, Zn, Zr, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu between precipitate and liquid fractions obtained during the fermentation process was measured. As a second step developed analytical procedure for chemical elements fractionation was applied for liquid fraction of wine must after first fermentation and finished wines after clarification. in grape juice and between and applied for samples obtained from different steps in the winemaking process. Results obtained are linked to the bioavailable fractions of the same elements determined in extracts in respective soils. Monovarietal grapes from major vineyard regions in Bulgaria were used for this study. Calculated correlation coefficients between elements concentrations in kinetically labile fractions in must and wine and elements concentrations in bioavailable fractions of soils were discussed from the view of geographical and botanical origin of studied wines. The chemical elements with highest discriminant power were defined. Final statistical treatment for the possibilities to assess the geographical origin of wine was based on cluster analysis.
