Tannins astringency

B Astringent (tannin-containing) plant parts tend not to be eaten. 

Dry white table wines differ from red table wines in characteristics other than color. They contain lower concentrations of the puckery and astringent tannins. They usually have a higher acid content which makes them somewhat lighter in body and fresher on the palate. Dry white wines also are usually simpler in their aroma in contrast to the complicated aroma and bouquet that can develop in a red table wine. While it is possible to make white table wines from red-skinned varieties, for the home winemaker this task is very difficult because it is almost impossible to remove all traces of the pigment-containing skins from the juice quickly enough to prevent some reddish or amber color from developing. 

Bate-Smith, E. C., 1977, Astringent tannins of Acer species, Phytochem. 16 1421-1426. 

Cinnamon is an ancient herbal medicine, long used to treat gastrointestinal disorders. It increases intestinal movement, heart rate, and perspiration by stimulating the vasomotor center. It improves circulation. The astringent tannins in cinnamon treat diarrhea the catechins treat nausea. Its essential oils are considered analgesic, antifungal, and germicidal. 

Most nuts have a large concentration of protein, and are an important food source for wildlife. Humans often eat nuts as well. Formerly, Native Americans would leach out the astringent tannins from acorns so they could be eaten. North Americans once prized the nuts of the American chestnnt (Castanea dentata) as a food. However, these trees have been decimated by an introduced fungus, known as the Chestnut blight. Now, nuts of the sweet chestnut tree (Cadtomea sakua) are occasionally served instead. 

Nevertheless, this type of seasoning has certain effects on the development of the compounds in the oak. In particular, most of the reactions described in the preceding paragraphs do not occur under these conditions (Table 13.18). Compared to naturally seasoned wood, oven-dried wood has a higher content of astringent tannins and bitter coumarins. It contains less eugenol, vanillin and methyl-octalactone, with a majority of the less odoriferous trans isomer. 

Astringent Tannin containing herb used for contraction of tissues. 

Bate-Smith E C 1978 Systematic aspects of the astringent tannins of Acer species. Phytochemistry 17 1945-1948... 

Bate-Smith EC 1981 Astringent tannins of the leaves of Geranium species. Phytochemistry 20 211-216... 

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