Posted by Yeasts need to incorporate unsaturated fatty acids (UFA) into their membranes to maintain fluidity during low-temperature fermentation. .In typical white wine fermentation, however, grape juice settling causes a deficiency in FAs, while the low-oxygen conditions prevent yeast from synthesizing UFAs and sterols . As a result, the yeasts produce saturated medium-chain FAs (MCFAs) to partially compensate for lack of membrane fluidity. Some of these MCFAs are released into the medium, where they reduce yeast viability and [may] even cause the fermentation to stop. Alpha-CD, but not beta- or gamma-CD sequester the MCFAs, preventing them from stopping fermentation.
In this paper the native cyclodextrins are studied for mitigating the inhibitory effects of MCFAs through their ability to encapsulate non-polar molecules. The results suggest that α-cyclodextrins encapsulate MCFAs by mitigating the toxic effects on yeast in rich MCFA media. Using α-cyclodextrins may thus be a promising strategy for mitigating the toxic effects of MCFAs and preventing sluggish and stuck fermentations in winemaking due to the presence of these compounds in the fermentation medium.
Galán NG, Sabaté AC, Borràs AJ, et al. (2026). Cyclodextrins improve grape must fermentability through their detoxifying effect on medium-chain fatty acids. Food Chemistry: X: 103589. https://doi.org/10.1016/j.fochx.2026.103589