Interactions of grape tannins and wine polyphenols with a yeast protein extract, mannoproteins and β-glucan

Julie Mekoue Nguela (1, 2) , Celine Poncet-Legrand (1) , N. Sieczkowski (2) , Aude Vernhet (1, 3)

1 SPO - Sciences Pour l'Oenologie
2 Lallemand S.A.S.
3 Montpellier SupAgro - Institut national d’études supérieures agronomiques de Montpellier

At present, there is a great interest in enology for yeast derived products to replace aging on lees in winemaking or as an alternative for wine fining. These are yeast protein extracts (YPE), cell walls and mannoproteins. Our aim was to further understand the mechanisms that drive interactions between these components and red wine polyphenols. To this end, interactions between grape skin tannins or wine polyphenols or tannins and a YPE, a mannoprotein fraction and a β-glucan were monitored by binding experiments, ITC and DLS. Depending on the tannin structure, a different affinity between the polyphenols and the YPE was observed, as well as differences in the stability of the aggregates. This was attributed to the mean degree of polymerization of tannins in the polyphenol fractions and to chemical changes that occur during winemaking. Much lower affinities were found between polyphenols and polysaccharides, with different behaviors between mannoproteins and β-glucans.

Mots clés: interaction; ITC; DLS; yeast protein extract; mannoproteins; β-glucans; grape and wine polyphenols; wine yeast; red wine; tannin; polymerization

Mots clés: oenologie; vinification; levure de vinification; polyphénol; vin rouge; tanin; polymérisation

Domaines: Biologie végétale

Julie Mekoue Nguela, Celine Poncet-Legrand, N. Sieczkowski, Aude Vernhet. Interactions of grape tannins and wine polyphenols with a yeast protein extract, mannoproteins and β-glucan. Food Chemistry, 2016, 210, pp.671-682. ⟨10.1016/j.foodchem.2016.04.050⟩. ⟨hal-01496813⟩