Effects of Non-Saccharomyces Yeasts on Color, Anthocyanin, and Anthocyanin-Derived Pigments of Tannat Grapes during Fermentation

Phenolic compounds can affect the sensory characteristics of quality wines, yet the chemical modifications induced by yeasts on phenolic compounds have been studied only to a limited extent. Forty-nine non-Saccharomyces yeast strains belonging to different genera were screened for their effects on color and fermentation capability in a synthetic must supplemented with anthocyanins from Tannat grapes. Total anthocyanins, color intensity, hue, and total polyphenol index were significantly affected (p < 0.001) by the different yeasts studied, and the effects on these parameters were highly diverse in the yeasts’ capacity for improving color indexes of the red grape model wines. Six strains belonging to the species Metschnikowia pulcherrima, Hanseniaspora guilliermondii, H. opuntiae, H. vineae, and H. clermontiae were selected to evaluate the production of anthocyanin-derived pigments; significant variations in the production of four compounds were found between them and compared with Saccharomyces cerevisiae. The formation of vitisin A, vitisin B, malvidin-3-glucoside-4-vinylphenol, and malvidin-3-glucoside-4-vinylguaiacol are reported for the first time for species of genera Hanseniaspora and Metschnikowia.