Tannins, definition properties

Thus one arrives at a valid definition of tannins for plant chemistry, insofar as their characteristic properties are concerned, without reference to the leather industry. Such a definition has been given by Swain and Bate-Smith (28) ... 

Tannins are, by definition, substances capable of producing stable combinations with proteins and other plant polymers such as polysaccharides. The transformation of animal skins into rotproof leather results from this property, as does astringency, fining and enzyme inhibition. Tannins react with proteins in each instance collagen in tanning. 

Definition From aq. extraction of fresh deseeded marc remaining after grapes are pressed to produce wine or juice contains anthocyanins, tartaric acid, tannins, sugars, minerals Properties Deep purple sol. in water Uses Colorant for beverages and pharmaceuticals... 

Currently, understanding the biometabolism of HTs, especially ETs, can contribute to the definition of their bioavailability and potential biological properties on humans. Although there is little information on the absorption, distribution, metabolism and excretion (ADME) of HTs in humans, trials with rodents and pigs, in vitro studies and fecal batch fermentations have contributed to understanding tannins metabolism. This fact becomes even more relevant for GTs since, to the best of our knowledge, there is a lack of studies focused on the biometabolism of GTs or GT-rich foodstuffs. 

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