Fate of fresh mushroom off-flavor markers during alcoholic fermentation: formation of novel acetylated derivatives

Abstract

Since the 2000’s, the occurrence of fresh mushroom off-flavor (FMOff) in wines has become a recurrent issue, linked to fungal alteration of grapes. Among the mushroom-related compounds identified in altered musts and wines, two analytical markers, 1-hydroxyoctan-3-one and octan-1,3-diol, clearly discriminate contaminated from healthy matrices (1,2). However, their fate during alcoholic fermentation has not yet been investigated. We hypothesized that these compounds could be acetylated by wine yeasts to form the corresponding esters. This study aimed (i) to develop an LC–MS/MS analytical method to quantify these compounds and (ii) to apply it to investigate their evolution during fermentation. Meunier musts contaminated with Crustomyces subabruptus under laboratory conditions were fermented under standardized conditions, and FMOff biomarkers were monitored throughout alcoholic and malolactic fermentations. The analytical method was validated in enological matrices and showed very satisfactory performance, with high repeatability and reproducibility (RSD < 10 %), good linearity (R² > 0.99), and high accuracy (analytical bias < 20 %). During alcoholic and malolactic fermentations, concentrations of 1-hydroxyoctan-3-one decreased while those of octan-1,3-diol increased, supporting the existence of a biochemical reaction. In addition, acetylated derivatives of octan-1,3-diol were identified for the first time, corresponding to two new compounds potentially involved in FMOff metabolism. These results open new avenues to better understanding the role of yeast strains in modulating these compounds, as well as the potential masking effect of their esters on wine aroma.

References

1. Delcros, L.; Costis, A.; Le Guerneve, C.; Collas, S.; Hervé, M.; Roland, A. (2023). First identification of a new molecule involved in the fresh mushroom off-flavor in wines: 1-hydroxyoctan-3-one. Food Chem. 413.
2. Ployon, S.; Suc, L.; Le Guerneve, C.; Augès, E.; Mahé, H.; Hervé, M.; Bloem, A.; Roland, A. (2025). High-throughput LC-MS/MS discrimination of musts and wines contaminated by fresh mushroom off-flavor on the basis of reliable and easily quantifiable analytical markers: 1-hydroxyoctan-3-one and its derivate octane-1,3-diol. Food Chem. 482.