Diferenciação da origem geográfica de vinhos elaborados com uvas de três regiões vitícolas de Santa Catarina através de análises isotópicas e elementos minerais

Abstract

Wine origin and typicity are important issues and big interest for producers, consumers and traders. Both are linked to the achievement of wine recognition by the consumer market. Brazil has continental dimensions and a wide winegrowing diversity regions, each one with unique characteristics. Santa Catarina occupies the fourth state place in Brazilian surface area with vineyards, on the other hand, it´s the second in wine production, showing a potential for this activity. In this study, samples of three regions in Santa Catarina were collected aiming differ them by geographic localization, using oxygen isotopic ratio analysis (18O) of water, carbon isotopic ratio (13C) of ethanol, and mineral 85Rb and 88Sr wine content. Varietal Carbernet Sauvignon and Merlot wines were elaborated by microvinifications, vintage 2013, from the regions: Carbonífera, Vale do Rio do Peixe and Planalto Serrano de São Joaquim. Isotopic analysis of oxygen and carbon were performed by mass spectrometry isotope ratio (IRMS), and mineral elements by inductively coupled plasma-mass spectrometry (ICPMS). Wine water average values of 18O in Cabernet Sauvignon wines were efficient to differ wines from the three regions, demonstrating higher average values for Vale do Rio do Peixe region (3,31‰), followed by Carbonífera region (1,48‰), and Planalto Serrano de São Joaquim region showed negative values (-2,70‰). Similarly to Cabernet Sauvignon, wine water average values of 18O in Merlot wines were effective in differentiating just two regions, the higher values were exhibited for Vale do Rio do Peixe (3,72‰), and lower values for Planalto Serrano de São Joaquim (-2,76‰). Oxygen isotopic ratio depends mainly of whether conditions during grape maturation and harvest. Wine ethanol average values for 13C in Cabernet Sauvignon wines were not able to differ the three regions of Santa Catarina, however average values found to Merlot wines were able, evincing more negative values in Planalto Serrano de São Joaquim (-29,55‰), and less negative to Vale do Rio do Peixe (-28,67‰). Further on the geographic differentiation, the 13C showed potential to differentiate varieties inside a region. In Vale do Rio do peixe region, wine ethanol average 13C for Cabernet Sauvignon wines (-29,80‰) showed difference to Merlot wines (-28,57‰), the same differentiation occurred to Planalto Serrano de São Joaquim region, where Cabernet Sauvignon wines demonstrated values of (-30,47‰) and Merlot wines (-29,55‰). A wide range of mineral elements such as B, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, Nb, Cd, Sb, Cs, Ba and Pb were quantified to geographic differentiation between the studied regions. None of the mineral elements individually studied in this work allowed the differentiation of the three regions studied for Cabernet Sauvignon wines. However, the results for Mg, Al, Ca, Mn, Se, Rb, Sr, Zr, Nb, Cs and Ba differentiated at least one of the studied regions in Cabernet Sauvignon wines, it was also possible to differentiate the two regions studied in Merlot wines. A group of 18O, B, Mg, Al, V, Mn, Co, Cu, Se, Rb, Sr, Cd e Sb results classified the three regions by 100%.