Tannin is a type of biomolecule. It is a bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds (amino acids, alkaloids).
Tannins are bitter astringent polyphenol chemicals of plant origin that are capable of binding and shrinking proteins. Their astringent quality is what causes the dry feeling in the mouth after eating/drinking foods rich in this type of polyphenols.
- COFFEE (about 83% of Americans drink coffee)
- Chocolate (with cocoa content 70% and higher)
- The tannins in coffee and tea adversely affect iron availability
Thus, drinking too much tea or coffee may lead to anemia. Consumption of one cup of tea with a meal has been found to decrease the absorption of non-heme iron in that meal by about 70%.
Adding lemon to tea helps reduce or neutralize these adverse effects of tannin polyphenols on iron intake.
Consuming foods rich in vitamin C (berries, citrus fruits, tomatoes, peas, dark leafy greens, bell peppers): helps in neutralizing the effects of tannin polyphenols on iron absorption due to this vitamin’s ability to increase iron absorption in the body.
-Class notes Food Chemistry.
“Tannins and Your Health.” Tannins and Your Health. Web. 27 Aug. 2015.