Astringency Perception in a Red Wine Context - A Review

Astringency is not considered one of the modern gustatory tastes. The understanding of astringency perception has evolved considerably over the past eighty years, but the exact mechanism is still undefined. This review aims to identify the current theory of astringency perception in the context of red wine. While astringency perception is a complicated mechanism that is not yet well understood, much research has focused on it. The studies discussed up to now have been done using red wine or wine-derived polyphenols. In a red wine context, astringency is driven by polyphenol concentration, galloylation and degree of polymerisation. Compounds that do not bind protein but are still strong astringent agonists are present in red wine. Among them, the role of polysaccharides and oligosaccharides is not clear, as these compounds are difficult to purify in quantities large enough for use in sensory studies. The literature strongly points to astringency being a compound perception. There is a stage of early protein binding, possibly as a "neutralising" effect for small amounts of dietary tannins with little actual perception, building into a more pronounced effect as tannin concentrations increase. A loss of lubrication in the oral cavity might announce the overpowering salivary protein capacity resulting from tannin concentrations, with direct detection of some astringent compounds once protein in the salivary fluid and the salivary pellicle are depleted.