Effect of Saccharomyces cerevisiae and Candida zemplinina on quercetin, vitisin A and hydroxytyrosol contents in Sangiovese wines.

Quercetins, vitisin A and hydroxytyrosol are phenolic compounds possessing several positive properties to human health. This paper refers on the possible effects of two wine yeast species, Saccharomyces cerevisiae and Starmerella bacillaris (synonym Candida zemplinina) on the accumulation of these compounds in experimental Sangiovese wines. A single lot of Sangiovese grapes was fermented by S. cerevisiae alone or by sequential inoculum of C. zemplinina and S. cerevisiae under two aeration conditions. The accumulation of quercetin and its glycosides resulted only influenced by must aeration. However, yeast species occurring in the fermentative process affected the relative abundances among the different forms of quercetin. Vitisin A contents were higher in wines produced in the presence of C. zemplinina. Finally, higher concentrations of hydroxytyrosol and tyrosol were found in wines produced by S. cerevisiae alone under non-aerated condition. The fermentation of different Sangiovese grape musts carried out by the assayed S. cerevisiae strain pointed out that slow fermentation kinetics lead to higher levels of hydroxytyrosol and tyrosol. The study underlines the role of yeast species in determining the accumulation of bioactive compounds in Sangiovese wine.