By Oge Okafor
It wouldn’t be out of place when it is said that a lot of us have never really given it a thought what exactly is in tea that gives it that distinguishing quality/characteristics from any other drink in the world.
We have come to know that tea is the most popular drink in the world, after water but there is something about tea: the aroma, the taste or maybe the ritual of seeping the perfect cup that is unique. There is more to tea than the pleasure of drinking it; otherwise it would not remain so popular for thousands of years. Chinese and Indians firmly believe that it is the tea that keeps them healthy and strong. English could not imagine life without restorative cup of tea when the going gets tough. So, what is in tea?
In the natural state and when it is brewed (brewed tea is also called the “liquor”), tea contains three primary components: Essential oils; polyphenols and caffeine.
Essential oils
These provide tea’s delicious aromas and flavors. Tea contains an immense number of fragrance components, with around 200 in green tea and more than 300 in black tea. The fragrance of tea helps people to relax and relieve stress, making tea desirable as a sort of aroma therapy.
Polyphenols
Their presence provides the “briskness” or astringency in the mouth and is the components that also carry most of the health benefits of tea. These are the most abundant compounds in tea leaves, making up 30-40 percent of their composition.
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouth-feel and are speculated to provide potential health benefits. Polyphenols in tea include catechins, theaflavins, tannins and flavonoids.
The most active ingredients of tea are proanthocyanidins, polymer chains of flavonoids. The best known kinds of flavonoids are catechins. Catechins are antioxidants, what it means is that they prevent oxidation which causes cell damage and consequent health problems in many organs and tissues. Freshly picked green leaves of tea contain almost 30 percent of catechins. Scientists do not always agree about which type of tea is richest in catechins, but it is generally believed that white and green teas are the richest and most potent. Researchers from the U.S. Department of Agriculture believe that this difference is not significant and that all teas are powerful antioxidants. As antioxidants, catechins help prevent the effects of stress and support healthy metabolism. As a consequence, they can lower blood lipids and blood pressure, prevent arteriosclerosis, drop blood viscidity and prevent blood clot formation.
Caffeine
Another active ingredient in tea is caffeine, a powerful stimulant. Caffeine is found naturally in coffee, chocolate, tea. Tea has more caffeine by weight than coffee. Caffeine provides tea’s natural energy boost. Caffeine constitutes about 3 percent of tea’s dry weight, translating to between 30 mg and 90 mg per 8-oz (250-ml) cup depending on type, brand, and brewing method. A study found that the caffeine content of 1 g of black tea ranged from 22 to 28 mg, while the caffeine content of 1 g of green tea ranged from 11 to 20 mg, reflecting a significant difference.
Tea also contains small amounts of theobromine and theophylline, which are stimulants as well, and xanthines similar to caffeine. Theobromine is also used to dilate blood vessels, as a diuretic, and heart stimulant.
The amounts of these substances in a cup of tea are very small though, so their net effect on the body is probably negligible. Some of the caffeine we ingest is metabolized into theophylline and theobromine, so every time you consume caffeine, you will indirectly increase your levels of these two caffeine metabolites.
Tea also contains theanine, which has psychoactive properties and has been proven to reduce mental and physical stress, improve mood and cognitive abilities, similar to coffee. It is a unique type of amino acid called L-theanine. It is mainly found in the tea plant (Camellia sinensis) and is able to cross the blood-brain barrier.
In humans, L-theanine increases generation of brain waves called Alpha waves, which are associated with alert relaxation. This is perhaps the main reason for the different, milder buzz that tea generates compared to coffee. L-theanine may affect neurotransmitters in the brain, such as GABA and Dopamine. Some studies have suggested that L-Theanine, especially when combined with caffeine, can improve attention and brain function
Physically speaking, tea has properties of both a solution and a suspension. It is a solution of all the water-soluble compounds that have been extracted from the tea leaves, such as the polyphenols and amino acids, but is a suspension when all of the insoluble components are considered, such as the cellulose in the tea leaves. So, the next time you lift that hot cup of refreshing and relaxing tea to your mouth, remember that these are the substances in tea you are ingesting and they make tea what it is.
►www.healthstatus.com; wikipaedia.com; healthline.com