Fitness of selected indigenous Saccharomyces cerevisiae strains for white piceno DOC wines production

Abstract

Verdicchio, Passerina and Pecorino are native grape cultivars of the Marche region, cultivated in winemaking area of Ascoli Piceno, in central Italy. In particular, Passerina and Pecorino varieties have been abandoned and forgotten for a long time and only in recent years are rediscovered and appreciated. Here, two indigenous yeasts, isolated from grapes of Verdicchio and Pecorino varieties and identified as Saccharomyces cerevisiae, were evaluated and compared with commercial starters cultures widely used for the vinification of Piceno DOC (Denominazione Origine Controllata) area at industrial scale. A polyphasic approach, including yeast genotyping, phenotypic traits evaluation and fermentative performance in natural grape juice, was applied to evaluate the fitness of strains. Using interdelta primers, the two selected cultures showed a unique profile while the results of microvinifications showed that both indigenous strains exhibited good enological parameters and fermentative aptitude comparable with that shown by commercial strains used as controls. The profile of volatile compounds of wines of indigenous strains was characterized by a significant high production of isoamyl acetate and ethyl esters at 22 °C and phenyl ethyl acetate at 16 °C. Overall results indicate that the two indigenous selected yeasts showed a genetic and phenotypic specificity and they could be profitably used to characterize the Piceno DOC area wines.