Influence of Saccharomyces cerevisiae wine strains on total antioxidant capacity

Abstract

The aromatic fraction of wines comprises a wide variety of compounds with different aromatic properties and antioxidant capacity, an important nutritional parameter. We selected Saccharomyces cerevisiae strains according to their ability to produce ethanol and chose 40 high ethanol-producing strains, all isolated from Nero d'Avola grapes, for testing in inoculated fermentations. The experimental wines obtained were analysed for total antioxidant capacity (TAC) and content of a number of by-products influencing wine aroma. The TAC in these 40 wines ranged from 0.625 to 3.3 mM/L ascorbic acid equivalents, and the wines could placed in three classes as a function of TAC, namely, low, medium, and high TAC. The majority of strains tested produced wines of the medium class, whereas only a few strains exhibited a high TAC. The strains that produced wines with an extremely low TAC are undesirable for use in the fermentation of Nero d'Avola grape must. Two fermentation by-products, acetic acid and isoamyl alcohol, were mainly responsible for wine variability. In terms of aromatic composition, strains determining low-medium TAC in the wines were characterized by a similar metabolic behaviour, which differed totally from that of strains determining a high TAC. © 2010 Springer-Verlag and the University of Milan.