The chemical composition of tea: simply about the unknown

Posted on Sep 13, 2022      46

Few people think about what exactly is in the composition of tea. However, the same ordinary cup contains about three hundred different chemical compounds, each of which has its own effect on the body. Many of these components have long been isolated and studied, but... not all of them. We have read about 20 scientific articles and talked to experts to break down the chemistry of tea once and for all.

The main chemical components of tea

Dried tea differs in its composition from fresh, freshly picked leaves because it has already been processed. Below we will write about “ready-made” teas, I.e. dried and ready to be brewed.

So, the chemical composition of dried tea can be divided into two parts: soluble and insoluble elements. The insoluble part affects physical structure and appearance of tea - it is cellulose, cellulose, proteins, lignin, fats, chlorophyll, other pigments and starches.

However, we are more interested in the soluble part, which contains all those healthful substances for which we appreciate tea. It also determines the taste of the drink. This part consists largely of flavonoids, alkaloids, tannins, amino acids and trace elements.

With flavonoids being responsible for tartness and bitterness, amino acids for sweetness and flavor, and alkaloids for bitterness and vigor.


This group includes catechins (epicatechin, gallocatechin, epigallocatechin, epigallocatechin gallate) and flavonols (kaempferol, quercetin, myricetin).

It is because of catechins that tea is included in the list of foods that improve health and increase longevity. Catechins are powerful antioxidants that can not only change the color, flavor, and tartness of the drink, but also bring tremendous benefits to the body.

The benefits of tea flavanoids are :

  • Epicatechin - has effects that mimic insulin and improve heart health.
  • Gallocatechin - improves the action of human cannabinoid receptors.
  • Epigallocatechin - protects cells from free radical damage.
  • Epigallocatechin gallate - reduces inflammation and prevents some chronic diseases, including heart disease, diabetes and some cancers.

Catechin content is higher in green and white teas because black tea undergoes an oxidation process, which reduces the content of this element. Catechins can make up to 30% of the dry weight of the tea. Epigallocatechin gallate is considered the most effective.


Tea contains purine group alkaloids - caffeine, theobromine and theophylline. Caffeine handles vivacity, efficiency, and clarity of mind. Even children know about its effects. But first, this is not all that it gives us, and second, there are two other substances, which are less known. They are very few in tea, but they do their job, too.

The benefits of tea alkaloids:

  • Caffeine - improves cognitive function, stimulates the central nervous system, reduces the risk of certain cancers, improves memory, guarantees the prevention of diabetes, stroke and Parkinson’s disease.
  • Theobromine - has diuretic, stimulant (unlike caffeine does not affect the central nervous system) and relaxant effects. Can lower blood pressure because it dilates blood vessels, and relax the bronchial muscles in the lungs (used as a cough medicine).
  • Theophylline - helps treat asthma and chronic obstructive pulmonary disease.

Some teas contain up to 5% caffeine, but it is quickly and successfully eliminated from the body because of its association with tannin. This allows us to drink tea in large quantities without fear of caffeine overdose.

Other Tea Components

The amino acids in tea are theanine, also known as L-theanine. This substance can increase mental concentration, improve sleep, and reduce anxiety. It promotes relaxation, lowers blood pressure, boosts immunity, and even weight loss.

This substance also provides the sweetness in tea. Leaves and buds harvested early in the season have a higher concentration of theanine and therefore taste sweeter.

The tannins in tea are represented by tannin. Its usefulness lies in its antimicrobial effects.

Saponins are foam-forming substances that also have several beneficial properties. These include reducing cholesterol levels, destroying pathogenic bacteria, inhibiting tumor growth, improving lipid metabolism, and preventing and treating obesity.

Micronutrients found in tea are potassium, calcium, magnesium, iron, phosphorus, etc.

Vitamins - tea can contain almost all vitamins, but it contains the most B vitamins, vitamin C, as well as P and PP.

Is there a difference in composition between black and green tea?

While green tea contains large amounts of monomeric catechins (epicatechin, gallocatechin, epigallocatechin, and epigallocatechin gallate), black tea is rich in oxidation products of catechins and catechin gallates, which appear during fermentation (theaflavin and thearubigins). As we wrote earlier, these two substances handle the astringent properties, bright aroma and color of black tea. They act as antioxidants in it.

The content of amino acids in green tea is also significantly higher than in black tea. The tannin content is often higher in black tea if it is a good quality tea.

Teg:   tea