Astringens

Astringency is a sensory perception characterized by a dry, puckering sensation in the mouth, often described as a "tightening" or "drawing" feeling. It is primarily caused by the interaction of certain chemical compounds with proteins in the mouth, particularly those found in saliva and on the tongue. The most common class of compounds responsible for astringency are polyphenols, which include tannins, flavonoids, and certain acids.

These polyphenols bind to salivary proteins, causing them to precipitate and form a film on the oral tissues. This film reduces the lubricating properties of saliva, leading to the characteristic dry and rough sensation associated with astringency. The intensity of the sensation can vary greatly depending on the concentration and type of astringent compound present, as well as individual sensitivity.

Astringency is a prominent characteristic of many foods and beverages, including unripe fruits such as persimmons and bananas, red wine, tea, coffee, and certain berries like cranberries. It can also be found in some medicinal herbs and pharmaceutical preparations, where it is utilized for its perceived constricting and healing properties on mucous membranes. While often associated with an unpleasant sensation, mild astringency can contribute to the complexity and desirable mouthfeel of certain products. Conversely, excessive astringency can be perceived as harsh or undesirable.