Detalle de: The diverse effects of yeast on the aroma of non-sulfite added white wines throughout aging

Semi-synthetic must containing standard nutrients, a phenolic and aromatic fraction extracted from Albariño grapes and synthetic precursors of 3-mercaptohexanol (MOH) and 4-mercapto-4-pentan-2-one (MMP) were fermented with three different selected commercial S. cerevisiae yeasts. Wines were subjected to anoxic aging at 50 °C for 1, 2, 5 and 8 weeks, and their volatile composition was comprehensively determined by the analysis of 86 different aroma compounds using five different GC methods. Yeasts exert a strong influence on wine aroma throughout the whole aging period. Their effects extend beyond the well-known actions on yeast secondary metabolites, including the formation of little amounts of Strecker aldehydes or the formation of acids precursors of fruity esters, and on the enzymatic actions on the different grape aroma precursors. Additionally, yeasts influence wine aroma; first, by producing SO₂ which reacts with β-damascenone and increases Strecker aldehyde production in fermentation; second, by inducing the differential accumulation of Strecker aldehydes during anoxic aging; and third, by determining the stability of MOH, likely because of its reaction with vinylphenols or other yeast-related electrophiles.