Role of mannoproteins in the activation of wine malolactic fermentation: Influence of the yeast and the extraction method

Identifier:  imarina:9525835

Handle: https://hdl.handle.net/20.500.11797/imarina9525835

Authors:  Torano, Paloma; Oyon-Ardoiz, Maria; Manjon, Elvira; Garcia-Estevez, Ignacio; Bordons, Albert; Rozes, Nicolas; Escribano-Bailon, M Teresa; Reguant, Cristina

Abstract:
This study focuses on the characterisation of mannoprotein extracts (MPs) obtained from active dry yeast of Saccharomyces cerevisiae and non-Saccharomyces strains, including those of Torulaspora delbrueckii, Lachancea thermotolerans, and Metschnikowia pulcherrima, and their effects on wine malolactic fermentation (MLF) carried out by Oenococcus oeni. Mannoproteins are essential components of the yeast cell wall, are released during the autolysis process, and vary in size, molecular weight, and protein content depending on the extraction method. In this work, it was observed that the MPs obtained through cellular autolysis induction had a higher molecular weight, a richer sugar composition-including mannose and glucose-and a higher protein content than the MPs obtained through the alkali medium method. All the MPs extracts had beneficial effects on MLF in white and red wines. The consumption of mannoprotein by O. oeni was observed in all the fermentations, indicating the relationship between MPs and O. oeni metabolism improvement. Finally, the addition of MPs did not significantly affect colour parameters, tannins, or anthocyanins at the end of MLF in red wines, keeping these components stable and, therefore, maintaining the final stability of the wine. In conclusion, this work demonstrates the potential of MPs as effective activators of MLF in wine.