We are all familiar with that strange feeling in the mouth after a sip of red wine or tea,or a bite of unripe fruit. It has been described as dry, leathery, and even furry. This astringent effect is caused by tannins or polyphenolic compounds that bind to mucins,lubricating proteins in the mucus membranes of the mouth. In the journal Angewandte Chemie, a Chinese and Korean research team has now shown the relationship between astringency and disrupted lubrication of the verbal cavity.
Source: phys.org