David Spector, Duncan Hamm,* and Katja Sander Jensen
*Novonesis A/S, Boege Alle 10-12, Hoersholm 2970, Denmark
(dunha@novonesis.com)

L-γ-glutamyl-L-cystinyl-glycine, commonly known as glutathione (GSH), plays a crucial role as an antioxidant in wine, helping to mitigate the loss of volatile flavor compounds susceptible to oxidation, as well as preventing oxidative browning and aroma changes. In recent years, particular interest in using GSH in winemaking has developed and as a result, yeast derivatives rich in this compound have been marketed to maximize and preserve flavor expression. Non-Saccharomyces yeasts (NSY) have been associated with producing higher concentrations of GSH than Saccharomyces cerevisiae, yet data on the production of this compound across different species or strains is limited.

This work investigates the potential of four commercial NSY strains from three species—Lachancea thermotolerans, Pichia kluyveri, and Torulaspora delbrueckii—to increase the GSH concentration in the final wine. Assessments will be conducted in two musts designed to emulate conditions for red and white or rosé wine fermentations, respectively. The initial yeast inoculation will take place with NSY before S. cerevisiae is inoculated 48 hours later.

Preliminary findings suggest that the non-Saccharomyces yeast strains exhibit varied capabilities in enhancing GSH levels, potentially offering winemakers new tools to improve wine quality and stability through natural antioxidant mechanisms. Further research and trials will illuminate the practical implications of these findings for winemaking practices, particularly for flavor preservation and oxidative stability.

Funding Support: Novonesis A/S (formerly Chr. Hansen A/S)