Polysulfides accumulation in white wines produced from different oenological yeasts

Amongst the different factors affecting wine quality, yeast plays a crucial role in winemaking. Besides the positive contribution to the wine bouquet, yeast metabolism can also be related to wine defects, with H2S being one of the most well-studied. Recent evidence has shown a novel accumulation pathway from H2S, originating from non-volatile polysulfides. In the present study, the effect of different oenological yeasts on the accumulation of polysulfides during wine fermentation was investigated. Nine different yeasts were used to carry out semi-industrial fermentations and the resulting wines were analysed using UHPLC-HRMS for the detection of cysteinyl and glutathionyl polysulfides. Significantly higher relative formations of the cysteinyl di- and trisulfide were found for C22 compared to ExperTi and pre-com, as well as for VL3 compared to pre-com. Moreover, fermentations with FR95 resulted in significantly higher accumulations of the glutathionyl trisulfide compared to vinifications with WB1, VIN13 and pre-com, and significantly higher values were found for the glutathionyl di- and tetrasulfide with FR95 compared to pre-com. Finally, the polysulfide profiles were used to rank the yeasts from high to low risk of formation of polysulfides, with CY3079 and EXC TXL having the highest and lowest potential risk, respectively