Wine tannins, saliva proteins and membrane lipids

• Published in: Biochimica et biophysica acta. Biomembranes 2021-10, Vol.1863 (10), p.183670-183670, Article 183670
• Main Author: Dufourc, Erick J.
• Format: Article
• Language: English
• Subjects: Astringency; Binding constants; Cholesterol; CMC; Lipid droplets; Mucous membrane dynamics; Nanocomplexes; NMR; Polyphenols; Proline rich proteins; Tannins; Taste sensation
• ISSN: 0005-2736; 1879-2642
• DOI: 10.1016/j.bbamem.2021.183670

Polyphenols have been part of human culture for about 6000 years. However, their mode of action in relation to wine tasting while eating is only beginning to be understood. This review, using analytical techniques and physicochemical concepts, attempts to summarize current knowledge and present an integrated view of the complex relationship between tannins, salivary proteins, lipids in food and in oral membranes. The action of tannins on taste sensations and astringency depends on their colloidal state. Although taste sensations are most likely due to interactions with taste receptors, astringency results from strong binding to proline-rich salivary proteins that otherwise lubricate the palate. Tannins disorder non-keratinized mucosa in mouth, possibly perturbing taste receptor function. The 10–15% ethanol present in wines potentiates this action. Cholesterol present in large quantities in keratinized mucosa prevents any disordering action on these oral membranes. Polyphenols bind strongly to the lipid droplets of fatty foods, a situation that reduces the astringency perceived when drinking a tannic wine, the so-called “camembert effect”. Based on binding constants mainly measured by NMR, a comprehensive thermodynamic model of the interrelation between polyphenols, salivary proteins, lipids and taste receptors is presented. Schematics of the multi-interactions that occur in the oral cavity when drinking wine with food. Tannins, proteins in saliva, lipids in food, mucous membranes in the mouth, taste receptors interacted together. The thickness of the arrows represents the strength of the interactions and gives a physico-chemical basis to astringency and to the 5 main taste sensations (salty, bitter, sweet, acid, umami). [Display omitted] •Tannins in wine exhibit CMC of several g/L and may associate into micelles•Salivary Proline-rich proteins (PRPs) bind polyphenols to produce nanocomplexes or precipitates.•Low-cholesterol membranes interact strongly with tannins and become disordered, ethanol potentiates this effect, whereas cholesterol-rich membranes, as in the keratinized oral palate, are insensitive to tannin-induced disorder.•Tannins bind strongly to lipid droplets in fatty foods.•3D structures, dynamics, binding constants of partners allow and integrated view of taste sensations and astringency