Effects of microbial populations on anthocyanin profile of Sangiovese wines produced in Tuscany, Italy

Abstract: The effects of wine yeasts and malolactic bacteria on the anthocyanin profile of Sangiovese wines produced by both commercial- and laboratory-scale winemaking processes were investigated. The mean anthocyanin profile of the wines obtained from commercial winemaking processes, carried out in several wineries in Tuscany, showed a distinctive anthocyanin pattern characterized by high percentages of malvidin-3-glucoside, without appreciable levels of acylated anthocyanins. This anthocyanin pattern, also shared by all wines produced in the laboratory, reproduces the peculiar profile of Sangiovese grapes and distinguishes Sangiovese wines from Merlot and Cabernet Sauvignon wines. Principal component analysis of all anthocyanin data showed that the Sangiovese wines did not group on the basis of wine-producing area, harvest year, or winery but were distributed along a longitudinal axis, owning to the variability of cyanidin-3-glucoside, peonidin-3-glucoside, and malvidin-3-glucoside percentages. This variability was independent of the yeast ecology during fermentation, at least if the yeast ecology was described at the level of yeast species. In both commercial and experimental wines, higher percentages of vitisin A, a malvidin-3-glucoside derivative, were dependent on the growth and dominance of Candida zemplinina in the early stages of vinification. The anthocyanin profile of the Sangiovese wines was also maintained after malolactic fermentation.