Tea pigment is a class of tea leaves and finished tea in the presence of colored substances, is the composition of the appearance of tea color, soup color and leaf color components, its content and changes in the quality of tea plays a crucial role.

Among the tea pigments, some are already present in the fresh leaves, which are called natural pigments in tea, and some are formed by oxidative condensation of some substances during processing. Tea pigments are usually divided into two categories: fat-soluble pigments and water-soluble pigments.

Fat-soluble pigments mainly play a role in the color of dried tea leaves and the color of the bottom of the leaves, while water-soluble pigments mainly have an effect on the tea broth.

Excluding unnatural added pigments, there are two kinds of natural pigments and processed pigments in tea, which we will introduce for you respectively.

Natural coloring in tea

(I) Fat-soluble pigments
Including chlorophyll and carotenoids, insoluble in water, soluble in non-polar organic solvents.

Chlorophyll

Chlorophyll is divided into chlorophyll a and chlorophyll b two kinds of chlorophyll in tea fresh leaves accounted for about 0.3% to 0.8% of the dry weight of tea leaves. The content of chlorophyll a is 2~3 times that of chlorophyll b. The total amount of chlorophyll depends on the variety and season. The total amount of chlorophyll varies greatly according to varieties, seasons and maturity. The chlorophyll content of fresh leaves with yellow-green leaves is low, and the content of fresh leaves with dark green leaves is high.

In general, green tea with high chlorophyll content is appropriate, black tea, oolong, white tea, yellow tea, etc. on the chlorophyll content requirements than green tea is low.

Carotenoids

Carotenoids are a class of colored compounds that range from yellow to orange-red. There are 17 carotenoid compounds found in tea, which are categorized into two main groups: carotenoids and lutein. Carotenoids, especially during black tea processing, are subject to extensive oxidative degradation to form a series of compounds of the violet rotenoids.Omori (1978) found that the addition of β-carotene during black tea processing was beneficial to the color and aroma of black tea.

(ii) Water-soluble pigments
Water-soluble pigment is a general term for coloring substances that can be dissolved in water. It generally refers to the oxidation products of anthocyanins, anthocyanins and catechins. Tea has been found in dozens of flower flavonoids, anthocyanins, is the main body of water-soluble pigments in tea.

Flavonoids, also known as flavonoids, mainly including flavonols and flavonoids are two types of compounds, which are the components of tea polyphenols. It is an important part of green tea soup color.

Color pigment formed during tea processing

In the process of tea processing will form a variety of pigments, which constitute the quality characteristics of tea, play an important role in different types of tea. For example, during the processing of black tea, due to the oxidation of polyphenols, theaflavins and thearubigins are formed, which makes black tea have its quality characteristics.

Theaflavins

Theaflavins are a class of pigments with orange-yellow color and astringency in black tea. It plays an important role in the intensity and freshness of the color and flavor of black tea, and is also the main component of the “bright” black tea broth color, and is the main substance in the formation of the “golden circle” of black tea. High theaflavin content of black tea soup color is golden yellow, high quality, extremely popular in the market.

RobertsE.A.H. pointed out that most of the reviewer’s assessment of the color is affected by theaflavin, the higher the content, the better the brightness of the soup color, golden yellow, the lower the content, the darker the soup color. Theaflavin and caffeine, theobromine and other complexes, the lower the temperature shows the phenomenon of milk coagulation, is the tea soup “cold after muddy” one of the important factors.

In the 1990s, nine theaflavin components have been isolated: theaflavin 1a, 1b, 1c, theaflavin acid, etc. Hilton and Cloughley (1980) study showed that theaflavin content and tea prices are positively correlated, through the measurement of the amount of theaflavin can be predicted by the black tea market price. Theaflavins have antiviral, lipid regulation, prevention of cardiovascular disease, and no toxic side effects.

Theobromine

Theobromine is a complex class of reddish-brown phenolic compounds. The content in black tea is about 6%~15% (dry weight). The substance is brownish red, soluble in water, water solution is acidic, weak irritation, is the main substance that constitutes the color of black tea soup, involved in the formation of “cold after muddy”.

Tea brown pigment

Tea fucoxanthin is a kind of water-soluble non-dialysis high polymerization of brown substances, its main components are polysaccharides, proteins, nucleic acids and polyphenols, by the further oxidation of theaflavin and theobromelain polymerization, which is an important factor in the darkness of the black tea broth color. Theaflavin is extracted from Pu-erh Tea (ripe tea) through modern physical technology, and it has beneficial effects on human body such as lowering blood lipids and blood sugar.

There are many kinds of pigments in tea, which are beneficial to human health. However, outside abnormal additive pigments can cause damage to the human body, so when you buy tea, you should be careful to select and carefully identify.

Whether to add coloring?

How to identify the market tea

Dried tea: too bright color
From a tea’s dry tea, we can tell a lot of things, such as the raw material’s old and young, and the processing technology’s good or bad. Similarly, we can also tell from a dried tea whether it has added coloring. Usually the added coloring of the dry tea will look very bright, such as added lead chrome green Biluochun, added sunset yellow Jinjunmei, and so on, will be gaudy and somewhat unusual.

Aroma: Impure
Tea with added coloring will give the tea an unusual odor. Tea if the flavor is not pure after brewing, there is a strange smell, miscellaneous smell and other difficult to identify the flavor, then these teas may be added flavor or coloring.

Tea broth: cloudy and opaque
In general, the tea broth should be very clear, only a few improperly processed turbidity, or more than one millimeter of tea varieties produced by the milli-muddy. The tea with added coloring, the tea broth after brewing will become very cloudy, not the usual color.

Different pigments form different qualities of tea, understanding the pigments in tea can help us intuitively choose tea, identify the authenticity of the tea, so that we can drink tea more healthily and enjoy life.