Contribution of alcoholic fermentation and post-fermentation maceration to red wine sweetness: new insights on N6-succinyladenosine release

Abstract

Recently, we identified in wine N6-succinyladenosine (NSA), a sapid molecule that contributes to the sweetness of red wines (Le Scanff et al. 2024). To gain insight on the biogenesis of this new impacting molecule, the kinetics release of NSA during alcoholic fermentation and post-fermentation maceration (PFM) was monitored by a LC-MS quantitative method. The impact of different enological parameters on NSA release were investigated, including the grape juice origin, the Saccharomyces cerevisiae strain used for alcoholic fermentation and the temperature during PFM. Our findings reveal that NSA, present in low amounts in grape juice and ranging from 10 to 200 µg/L, steadily increases during alcoholic fermentation, reaching final level of 500 to 1000 µg/L. Likewise, it appears that the post-fermentation maceration has a strong impact on NSA release, achieving concentrations higher that its perception threshold (>5000 µg/L). Both the duration and the temperature of PFM affect the kinetics of NSA release. By using flow cytometry, we demonstrated that NSA release is linked to yeast mortality occurring during the PFM, hence suggesting a positive effect of yeast autolysis. However, the biochemical origin of NSA remains to be more precisely determined. Finaly, this work reveals that the concentration of yeast cells at the end of alcoholic fermentation is a key factor influencing the final NSA concentration in wines. Besides, significant differences are observed in wines after MPF when different commercial wine yeast strains were used to perform alcoholic fermentation, paving the way for the selection of new yeast strains.

References

Le Scanff M., Marcourt L., Rutz A., Albertin W., Wolfender J.-L., Marchal A. Untargeted metabolomics analyses to identify a new sweet compound released during post-fermentation maceration of wine. Food Chem., 2024, 461, 140801.