Impact of addition of fumaric acid in the first stages of wine production

Fumaric acid is a promising oenological tool known for its ability to block unwanted malolactic fermentations due to its antibacterial properties. While its use as an acidifier in musts and wines is currently being debated, its interaction with yeast has long been recognized, yet in-depth studies are lacking. In this work, we investigated the impact of fumaric acid on the viability and fermentation performance of a pool of S. cerevisiae strains and other yeast species of oenological interest in experimental laboratory fermentations. In addition to collecting kinetic and microbiological data, we thoroughly characterized the resulting wines by analysing all interme­diates of the Krebs cycle for possible traces of fumaric acid, which was added to the grape must. Our results demonstrate that fumaric acid does not significantly alter the activity of S. cerevisiae, though we were able to identify some markers of its presence. Furthermore, a higher concentration of this molecule was found in the finished wines compared to the controls, suggesting a new approach for tracing fumaric acid in wine. Although preliminary, our tests on non-Saccharomyces yeasts revealed divergent behaviours among the species, which paves the way for further research.