Mechanisms of astringency: Structural alteration of the oral mucosal pellicle by dietary tannins and protective effect of bPRPs

Sarah Ployon (1) , Martine Morzel (1) , Christine Belloir (1) , Aline Bonnotte (2) , Eric Bourillot (3) , Loïc Briand (1) , Eric Lesniewska (3) , Jeannine Lherminier (2) , Ece Aybeke (1) , Francis Canon (1)

1 CSGA - Centre des Sciences du Goût et de l'Alimentation [Dijon]
2 Agroécologie [Dijon]
3 ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne

The interaction of tannins with salivary proteins is involved in astringency. This paper focussed on saliva lining oral mucosae, the mucosal pellicle. Using a cell-based model, the impact of two dietary tannins (EgC and EgCG) on the mucosal pellicle structure and properties was investigated by microscopic techniques. The role of basic Proline-Rich-Proteins (bPRPs) in protecting the mucosal pellicle was also evaluated. At low (0.05 mM) tannin concentration, below the sensory detection threshold, the distribution of salivary mucins MUC5B on cells remained unaffected. At 0.5 and 1 mM, MUC5B-tannin aggregates were observed and their size increased with tannin concentration and with galloylation. In addition, 3mM EgCG resulted in higher friction forces measured by AFM. In presence of bPRPs, the size distribution of aggregates was greatly modified and tended to resemble that of the “no tannin” condition, highlighting that bPRPs have a protective effect against the structural alteration induced by dietary tannins.

Mots clés: Atomic Force Microscopy; Friction; Astringency; Salivary mucins MUC5B; EgCG; Scanning Electron Microscopy; R146/MUC1 cells; IB5

Domaines: Alimentation et Nutrition; Physique [physics]

Sarah Ployon, Martine Morzel, Christine Belloir, Aline Bonnotte, Eric Bourillot, et al.. Mechanisms of astringency: Structural alteration of the oral mucosal pellicle by dietary tannins and protective effect of bPRPs. Food Chemistry, 2018, 253, pp.79-87. ⟨10.1016/j.foodchem.2018.01.141⟩. ⟨hal-02405048⟩