Tannins are a class of substances in tea, especially black tea, which have the tendency to have a bitter taste and astringent properties. Teas high in tannins can be referred to as tannic.
People talk of some teas having a “tannic quality”, which generally explains the pairing of a sharp bitterness with a strong astringency in black teas with a dark color. This bitterness contrasts with the bitterness imparted by caffeine, which require not be coupled with astringency, and can happen in teas with an extremely light color.
Less oxidized teas, like green tea, can be extremely astringent and bitter even while being light in color. This remains in large part because they consist of other chemicals, such as catechins, which share certain resemblances with tannins, but lack the dark color.
American society, regrettably, has actually had many health trends identifying entire class of compounds as either “great” or “bad”, and tannins have fallen onto the “bad” side of public understanding, much as antioxidants have fallen onto the “excellent” side. People holding these beliefs would likely be surprised to learn that the tannins in tea are anti-oxidants.
Types of Tannins in Tea
The tannins discovered in tea are called thearubigins, a class of chemicals which includes theaflavins. These chemicals are formed in black tea when the antioxidants inherent in green tea, called catechins, become oxidized. Tea does not consist of any tannic acid.
The tannins in tea are therefore accountable for the antioxidant activities of black tea and lots of other dark (oxidized) teas, including more-oxidized oolong teas. However, these same chemicals can also have negative influence on health; the tannins are likewise responsible for tea’s inhibiting impact on iron absorption.
Not all dark-colored substances in tea are tannins
Numerous teas, consisting of some oolongs are roasted, giving them a dark color which superficially resembles black tea. These other substances have an unique taste and mouthfeel– as is evidenced by the much smoother taste and lower astringency and some roasted oolongs, relative to black teas that are likewise dark. Oolongs that are both oxidized and roasted can have a dark color from a mix of tannins and numerous other substances formed by the roasting.
Nutritional and Health Impacts of Tannins
Tannins are a varied class of substances, and have varied effects on health. Tannins are typically considered antinutritional, as animal research studies recommend they can reduce net metabolizable energy and protein digestibility. Nevertheless, these same substances frequently exhibit anti-carcinogenic and anti-mutagenic properties, most likely due to their antioxidant activity. Tannins also have well-documented antimicrobial properties, reliable against many bacteria, fungi, and infections.
Many particular substances within the class of tannins have other biological activity or medical uses, that include speeding of blood clot, decrease of blood pressure, and effects on the liver and immune system.
High Tannin Teas
In basic, teas rich in tannins have the tendency to be easier to get, and have the tendency to be less expensive, than low-tannin teas. Low-qualilty black teas, such as the fannings or dust in the majority of tea bags, are normally high in tannins, and as a general guideline, lower grades of tea tend to have more tannins than higher grades. Nevertheless, grade does not constantly correspond to quality, and there are top quality teas and craftsmen teas that are rich in tannins as well.
Are the Tannins in My Tea Good for Me?
Tannins are found not just in tea, where they are vital to the production of tea’s taste and color, but they are found in numerous foods, such as cheeses and nuts, and other products. A plant contains tannin as a defense, to avoid it from being eaten. The bitter taste, in addition to disturbance with starch food digestion, has the tendency to make the plant unpalatable to lots of animals, though tannins are not concentrated enough in tea to disrupt food digestion if they are used in moderation.
For some of us, the bitter taste of tannin is satisfying. Nevertheless, as constantly, people respond in a different way to numerous food elements, and for some, tannins cause headaches.
Catechin, one of a number of thousand proanthocyanidins or polyphenols, is a type of tannin strange to tea. Numerous of these proanthocyanidins are found to lower total cholesterol and enhance the ratio of “great,” or HDL, cholesterol to “bad,” or LDL, cholesterol. They likewise appear to lower blood pressure, reduce the risk of cancer, promote the immune system, and have anti-bacterial properties.
Tea and coffee both consist of caffeine, a stimulant, but tea also has tannin and theanine, which are relaxing. The presence of these chemical substances together in tea permits you to control its impact. When boiling water is put onto the tea leaves, in the first two minutes all the caffeine is extracted. At this point tea is most revitalizing. During the next few minutes, tannin and theanine are gradually drawn out of the tea leaves.
After about 5 minutes this will have the tendency to counteract the effects of the caffeine and will make a more relaxing, calming tea. If you want just the relaxing effects from tea, dispose of the liquid from the first two minutes of steeping and use only the liquid from subsequent steeping, containing little caffeine and more tannin and theanine.
The concern of whether tannins are connected to migraine headaches is still unsolved. Tannins in tea are stated to restrict capillary, however a migraine is generally caused by dilation of capillary, so how can tannins cause migraines? The answer may lie with the neurotransmitter serotonin. If tannin binds starches– needed by the body to produce serotonin– in individuals who are very sensitive to their serotonin levels, this lack of serotonin can lead to a migraine.
Tea does not consist of any tannic acid. This misconception stems from confusion between tannins (a broad class of compounds) and tannic acid, a particular type of tannin. Tea includes tannins besides tannic acid. Tannins have both favorable and negative results on health, and like a lot of substances, are healthiest in moderation.
Too high a concentration of tannins in a cup of tea can lead to an unpleasantly astringent cup, but tannins also impart a sensation of body and thirst to a tea, and produce a richer mouthfeel: a black tea with too few tannins would be most likely to seem watery, weak, or thin-bodied.
Good luck! Have a nice weekend.