Cyclodextrins improve grape must fermentability through their detoxifying effect on medium-chain fatty acids

Through their inhibitory effects on yeast metabolism, medium-chain fatty acids (MCFAs) are one of the most frequent causes of stuck and sluggish fermentations (especially white grape must fermentation) in winemaking. A common strategy in winemaking to mitigate or correct the inhibitory effects of medium-chain fatty acids (MCFAs) on alcoholic fermentation is the addition of yeast hulls. In this paper we study α, β and γ-cyclodextrins as alternatives for mitigating the inhibitory effects of MCFAs through their ability to encapsulate non-polar molecules. Our 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.