Glutathione production by non-Saccharomyces yeasts and its impact on winemaking: A review

• Published in: Food research international 2022-06, Vol.156, p.111333-111333, Article 111333
• Main Authors: Binati, Renato L., Larini, Ilaria, Salvetti, Elisa, Torriani, Sandra
• Format: Article
• Language: English
• Subjects: Active dry yeasts; Glutathione; Inactivated dry yeasts; Multistarter fermentation; Non-Saccharomyces yeasts; Saccharomyces cerevisiae; Wine quality; Winemaking
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2022.111333

[Display omitted] •GSH is a major thiol compound naturally present in yeasts, grapes, and wine.•GSH is increasingly used in oenology for its strong antioxidant activity.•High GSH content in non-Saccharomyces yeasts enhances industrial biomass production.•Non-Saccharomyces yeasts can be prized as GSH-enriched active and inactivated dry yeasts.•Multistarter fermentations with selected strains increase GSH accumulation in wine. Glutathione (GSH) is a non-protein thiol naturally present in grape berries and produced by yeasts during fermentation. It has a strong antioxidant activity; thus, the addition of pure GSH during winemaking is recommended to limit the oxidative phenomena of wine, preserving sensory characteristics and stability, ultimately promoting a healthier product by reducing the need for SO2 addition. A promising alternative approach considers the use of yeast starter cultures high producers of this compound in situ, during the fermentation process, in substitution of external GSH addition. Recent research showed that multistarter fermentations with non-Saccharomyces yeasts produce even higher concentrations of GSH compared to single Saccharomyces cerevisiae. Accumulation of GSH in yeast cells is also considered valuable during the growth and dehydration of biomass for starter production, aiding strains to overcome the stressful conditions of industrial process. Moreover, a current trend in oenology is the use during fermentation of inactivated dry yeasts preparations as a source of nutrients, and many of them contain GSH-enriched cells. The aim of this review was to assess the significance of GSH production for the exploitation of wine-related non-Saccharomyces yeasts, both in starter biomass production and during fermentations, which were until now studied in detail for S. cerevisiae. This compendium highlights an interesting new feature of non-conventional yeasts and upgrade the strategy of multistarter fermentation as a valuable tool to positively modulate wine composition.