tannin(redirected from Tannins)
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Related to Tannins: tannic acid
a substance obtained from nutgalls, oak bark, and other plant parts, formerly used in medicine as an astringent. It is no longer used alone because it can be absorbed through mucous membranes or damaged skin in amounts sufficient to produce hepatic necrosis, although it is still used as a component of dermatological preparations.
Any one of a group of complex nonuniform plant constituents that can be classified into hydrolyzable tannins (esters of a sugar, usually glucose, and one or several trihydroxybenzenecarboxylic acids) and condensed tannins (derivatives of flavonols). Tannins are used in tanning, dyeing, photography, and as clarifying agents for beer and wine. Sometimes used synonymously with tannic acid. Tannins form black stains in the presence of iron.
Any of a family of compounds that react with proteins to produce a leathery coating on animal tissues and give woods their brown, red and yellow hues; tannins are anti-inflammatory, antimicrobial and astringent.
A complex nonuniform plant constituent; used in tanning, dyeing, photography, and as clarifying agents for beer and wine.
tannina complex organic compound occurring widely in plant sap, particularly in bark, leaves and unripe fruits, that is used in the production of leather and ink.
Complex nonuniform plant constituent used in tanning, dyeing, photography, and as clarifying agents for beer and wine. Sometimes used synonymously with tannic acid.