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Abstract

The capacity of yeast lees to remove thiols was investigated in a synthetic medium and in wine. In a synthetic medium, yeast lees are able to reduce thiol concentration with a concomitant production of a disulfide. In wine, thiol consumption is lower than in the synthetic medium and no disulfide formation occurs. Though free SH units seem to be partially involved in the thiol consumption process, this does not seem to require molecular oxygen. Since thiol consumption and disulfide formation have been shown to be inhibited by EDTA, it is suggested that metallic cations may be involved in both phenomena.

Yeast mannoproteins: Organoleptic modulating functions, mechanisms, and product development trends in winemaking

“…Ethylphenols (mainly 4‐ethylphenol and 4‐ethylguaiacol) may interact with MPs due to the π–π stacking between the aromatic ring of ACs and the of proteic part of MPs, this interaction can be further stabilized by the formation of H‐bonds (Chassagne et al., 2005; Petrozziello et al., 2014; Pradelles et al., 2008). The cysteine residues of yeast MPs may react with free thiols with the presence of some metallic cations such as Cu(II), to produce MP‐adducted disulfides (Lavigne‐Cruège & Dubourdieu, 1996; Lu et al., 2018; Vasserot et al., 2003). These interactions and reactions MPs involved in can decrease the release of off‐odor volatiles, thus improve wine aroma quality.…”

Autochthonous yeast populations from different brazilian geographic indications

“…This shows that the high incidence of Saccharomyces cerevisiae obtained from Merlot wine lees was not so obvious. The yeasts lees at the end of alcoholic fermentations utilize oxygen at different rates [23], showing fully metabolic activity and can reduce thiol concentration of wine [79]. One strain of Saccharomyces cerevisiae 2MBS12 showed skill for wine production.…”