What are Tannins in Tea?

Tannins are naturally occurring chemicals found in found in organic matter such as leaves and wood. Tannins are used in the process of tanning leather, and hence the name. Tannins are believed to lend the astringent taste to a brew.
High levels of tannin in tea cause a bitter taste in the brew coupled with strong astringency. These characteristics are exhibited in most Green and Black teas. Thearubigins are the tannins found in tea leaves, mostly theaflavins. When anti-oxidising agents in tea get oxidised, it leads to the production of theaflavins.
The antioxidant properties in teas are due to the tannins present in the leaves. Tannins have anti-carcinogenic and anti-mutagenic properties due to their anti-oxidising nature. They help in ridding the body of harmful microbes such as bacteria, viruses and fungi. They can also speed up the clotting of blood, thus having a healing effect on injuries. Tannins are also known to stabilize blood pressure. However, while they have positive effects on the body, they can also cause negative outcomes.

The Negatives

Tannins can have negative effects on nutrition and digestion. They can obstruct the ability of the body to absorb iron, which can be the cause of numerous other health-related issues.

A high content of tannin in tea can lead to jaw pain. This is because the astringency and bitterness of the tea causes a rise in the secretion of saliva in the mouth. Interestingly, tannin can also be the cure for jaw pain, due to its anti-inflammatory and anti-bacterial properties.
How much tannin is present in teas?

The content of tannin in Green Teas is lower than that in Black Teas. first flush tea from Darjeeling contains negligible levels of tannin. Teas with a high tannin content are cheaper and more easily available in the market as compared with non-tannic teas. The content in each variety of tea differs, and can also differ in the brew based on the steeping time prior to consumption.

What are antioxidants in tea?

Besides being the most consumed beverage in the world after water, tea is also one of the healthiest drinks available. As far as health is concerned, its preference over coffee stems from its lower content of caffeine. However, tea is also believed to contain a large number of antioxidants, which boost its placement in the ranking of healthy beverages.

 

Free radicals

 

In order to understand what antioxidants are, it is important to understand what are free radicals. Free radicals are produced on the separation of weak chemical bonds. Free radicals are highly unstable as molecules, and can only gain stability on the addition of an electron. It seeks an electron to gain stability and attaches to a stable molecule, this rendering the stable molecule unstable in the process. This cascading effect damages cells in the long term. Free radicals are produced during metabolism for their role in the immune system of the body. However, environmental pollutants and radiation around us cause a proliferation in the production of free radicals, leading to unfavourable effects on the body. Anything above normal levels of free radicals in the body require an increase in antioxidant levels to counter their ill effects.

 

Antioxidants prevent oxidation in the body. Foods such as fruits, vegetables and tea are rich in antioxidants, thus helping the body combat increases caused by free radical production. Antioxidants in tea are a group called flavanoids.

 

Leaves of the Camellia Sinensis plant are used to produce all the varieties available. The differences in the antioxidant levels are due to the variations in the processing.