Tea Science | What are the health benefits of tea?

Nowadays, tea has gradually become an indispensable element in people's daily life. According to a large number of scientific research reports, drinking tea is beneficial to human health. Tea contains a variety of functional ingredients, which are the material basis for the health benefits of tea. So what are the main substances? Let the editor tell you one by one.

How much do you know about the beneficial substances in tea?

Tea polyphenols and their derivatives

Tea polyphenols are also called tea tannins and tea tannins.

Its content generally accounts for 18% to 36% of the dry weight of tea leaves.

Found in new shoots and various organs of tea trees

It has very important physiological activity to the human body

Polyphenols in tea have antibacterial properties

And can remove excess free radicals in the body

Tea polyphenols are rich in phenolic hydroxyl groups

Able to bind to free radicals

"Sacrifice the self for the sake of the overall situation"

Achieve the effect of scavenging free radicals

(Tea polyphenols)

What are free radicals?

Free radicals are the product of normal human metabolism. Under normal circumstances, free radicals are continuously produced in the human body and are cleared away by the antioxidant system. The free radical level in the body is controlled within a certain range and will not cause obvious harm to the human body.

However, when certain external factors cause excessive free radical generation and the antioxidant system is unable to function, free radicals will gradually accumulate. Free radicals react with proteins, DNA, lipids, etc., damaging the body's normal functions, inducing diseases, and accelerating aging.

Alkaloids

Alkaloids in tea are classified into

Caffeine, Theobromine, and Theophylline

The highest content of caffeine

Accounts for 2% to 4% of the dry matter of tea leaves

Theobromine and theophylline account for about 0.05% and 0.002% respectively

They all have the effect of stimulating the central nervous system

Eliminate fatigue, refresh the mind and improve thinking

Caffeine can stimulate gastric acid secretion and increase appetite

Accelerate intestinal motility and improve gastrointestinal function

(caffeine)

Theanine

Theanine is the main amino acid component in tea.

Non-protein amino acids

Currently, 26 amino acids have been found and identified in tea.

Accounts for 1% to 4% of the dry matter of tea leaves

Theanine is a "nerve relaxant"

Enhances alpha waves in the brain

Alpha waves can calm the mind and soothe the body and mind

Tea polysaccharides

Sugars also called carbohydrates

It is the primary product of plant photosynthesis

It is also a precursor for the synthesis of many other ingredients

Tea polysaccharides are composed of sugars, pectin and protein.

It is a biologically active substance in tea.

Has antioxidant and anti-inflammatory effects

Can regulate intestinal flora

Control obesity

Vitamins

Vitamins are essential for maintaining human health.

Trace organic matter

Participate in regulating the growth, metabolism and development of the human body

Can clear the liver, improve eyesight and relieve eye fatigue

However, these substances cannot be directly synthesized in the human body.

Must be taken from food

Vitamin content in tea leaves accounts for % of dry weight of tea leaves

0.6%～1.0%

Divided into fat-soluble vitamins and water-soluble vitamins

Wait, here I want to know what fat-soluble vitamins are in tea? What water-soluble vitamins are there?

The fat-soluble pigments in tea mainly include: vitamin A, vitamin D, vitamin E, vitamin K, etc.

The water-soluble pigments mainly include: vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, folic acid, biotin, etc.

Mineral elements

Tea contains essential

Macroelements and trace elements

Elements with a content of 0.01% or more in organisms

We call this a constant element

Elements with a content of less than 0.01% in organisms

We call them trace elements

How do we distinguish between the major elements and trace elements here?

Phosphorus, calcium, potassium, sodium, magnesium, sulfur, etc. in tea are all macroelements, while selenium, fluorine, iron, manganese, zinc and iodine are all trace elements.

pigment

The many pigments present in tea leaves are called

Natural Colors

Some pigments are formed by oxidation during processing.

According to the solubility properties of the pigment

We can divide it into two categories: fat-soluble and water-soluble

Fat-soluble pigments include chlorophyll, carotenoids, etc.

Water-soluble pigments include anthocyanins, flavonoids and

Oxidation products of catechins

After reading this, will you be amazed that tea contains so many substances that are beneficial to health!

So how do we drink tea scientifically?

The editor will reveal it to you in the next issue~

Stay tuned!

Source of this article: Zhou Zhixiu, Jiang Yongwen, Ruan Haogeng, "Tea Art Master Training Textbook Ⅰ" (China Agriculture Press, 2021)

Some pictures are from the Internet

Reviewers: Jiang Heyuan, Researcher, and Xu Yongquan, Researcher, Tea Research Institute, Chinese Academy of Agricultural Sciences