Can you tell me how tea is classified and what types of famous teas our country belongs to?

Introduction to tea classification

There are many varieties of tea, among which China has the most. At present, there is no unified method for tea classification, and there are different classification methods according to different standards. Among them, Professor Chen Rong of Anhui Agricultural University proposed that based on the production method and quality, the primary tea leaves can be divided into six major tea categories: green tea, yellow tea, dark tea, green tea, white tea, and black tea in order of the degree of oxidation of tea polyphenols. . This method has been widely used in the industry. In addition, based on the product form of tea, tea can be divided into seven major tea categories: black tea, green tea, scented tea, oolong tea, white tea, pressed tea and instant tea.

In foreign countries, the classification of tea is relatively simple. In Europe, tea is divided into three major tea categories: black tea, oolong tea, and green tea according to product characteristics. In Japan, tea is divided into unfermented tea, semi-fermented tea, fully fermented tea, and post-fermented tea according to the degree of fermentation of tea.

Basic ingredients of tea:

Catechins: commonly known as ' Tea tannin is a unique component of tea, which has a bitter, astringent taste and astringent properties.

Caffeine: It has a bitter taste and is an important component of the taste of tea soup.

Minerals: Tea is rich in 11 minerals including potassium, calcium, magnesium, and manganese.

Functions of the basic components of tea:

Catechins:

Commonly known as 'tea tannins', they are unique components of tea and have a bitter, astringent and Convergence. It can be combined with caffeine in tea soup to alleviate the physiological effects of caffeine on the human body. It has the effects of antioxidant, anti-sudden mutation, anti-tumor, reducing blood cholesterol and low-density lipoprotein content, inhibiting blood pressure rise, inhibiting platelet aggregation, antibacterial, and anti-product allergy.

Caffeine:

It has a bitter taste and is an important component of the taste of tea soup. In the black tea soup, it combines with polyphenols to form a complex; when the tea soup is cold, it forms an emulsification phenomenon. The unique catechins and their oxidation condensates in tea can slow down and sustain the excitatory effects of caffeine. Therefore, drinking tea can keep people clear-headed and have more endurance when driving long distances.

Minerals:

Tea is rich in 11 minerals including potassium, calcium, magnesium, and manganese. Tea soup contains more cations and less anions, so it is an alkaline food. It can help body fluids maintain alkalinity and maintain health.

1. Potassium: Promotes the elimination of blood sodium. High blood sodium content is one of the causes of high blood pressure. Drinking more tea can prevent high blood pressure.

2. Fluoride: It has the effect of preventing tooth decay.

3. Manganese: It has antioxidant and anti-aging effects, enhances immune function, and helps in the utilization of calcium. Since it is insoluble in hot water, it can be ground into tea powder for consumption.

Vitamins:

1. Carotenoids: They can be converted into vitamins in the human body, but they must be drank with tea to supplement.

2. B vitamins and vitamin C: They are water-soluble and can be obtained from drinking tea.

Other functional ingredients:

1. Flavonols have the effect of strengthening capillary walls and eliminating bad breath

2. Saponin fights cancer. Anti-inflammatory effect.

3. Aminobutyric acid is produced when tea leaves are forced to undergo anaerobic respiration during the tea making process. It is said that Jiayelong tea can prevent high blood pressure.

Classification and identification of tea tree varieties:

Tea tree varieties are divided into two categories according to their reproduction methods: sexually propagated varieties and asexually propagated varieties. Varieties propagated through sexual means (seeds) are called sexually propagated varieties, referred to as sexual varieties; varieties propagated through asexual means (cuttings, etc.) are called asexually propagated varieties, referred to as clonal varieties. In tea production, clones with higher economic value are often called improved clones. Because sexual varieties are propagated by seeds, the main root of the seedlings is obvious and is a tap root system. The traits of the plants in the population are mixed and uneven. Clonal varieties are generally propagated by short-tassel cuttings. The traits of each plant in the population are uniform and short-tassel. The cutting seedlings have no main roots and are fibrous root systems. There are short spike marks on the root neck, which makes them easier to identify.

The excellent traits of clonal varieties can be passed down from generation to generation. They have the characteristics of high yield, excellent quality, strong tenderness of buds and leaves, neat germination, consistent shape, size and intrinsic quality of buds and leaves, and easy picking and processing. Therefore, clonal varieties are widely used in tea production. has been widely promoted and applied. For example, the Fuding Dabai tea variety originated in Fuding County, Fujian Province. Although it has a cultivation history of more than 100 years, it is still one of the improved varieties that are keenly promoted in the majority of tea areas. Tea tree varieties are all selected and bred under the ecological conditions of a specific region. Varieties that are native or bred in one area are divided into adaptive varieties or non-adaptive varieties according to their adaptability after being introduced to other areas for cultivation. The so-called adaptability refers to the requirements of the normal growth and development of tea trees on the natural conditions such as temperature, light, frost-free period, precipitation, soil acidity and other conditions in the cultivation area. The adaptability of a variety can be identified based on the growth potential, stress resistance, yield and quality of the tea tree of the variety in the area where it is introduced and cultivated. A certain variety of tea tree grows well in the introduced and cultivated area, has strong stress resistance, strong buds and leaves that remain tender, high yield, and excellent tea quality. Its overall performance is consistent with that of the original place, indicating that the variety has strong adaptability in this area. . Tea tree varieties are divided into five categories based on stress resistance: weak stress resistance, weak stress resistance, strong stress resistance, strong stress resistance and high stress resistance. The so-called stress resistance refers to the tolerance or resistance of tea trees to adverse environmental factors such as cold, drought, disease, and insects. Generally, identification is carried out based on the degree of damage to the leaves of each tea variety under the above adverse environmental factors, combined with the damage to the branches, using a 5-point scale for resistance scoring and grading. Tea tree varieties can be divided into four categories according to their germination stages: early-growing, early-growing, medium-growing and late-growing. The germination stage of tea tree varieties is identified by observing the germination process of overwintering axillary buds. The germination process of overwintering buds is generally divided into four phenological stages: fish leaf stage, one leaf stage, two leaf stage, and three leaf stage. Generally, the date when the 20 axillary buds of a variety reaches a certain phenological stage is the date when this variety reaches that phenological stage. Observations during the germination period need to be repeated for three years, using Fuding Dabai tea variety as a control. The methods for observing the budding period of tea tree varieties include visual inspection and tagging. The visual method estimates based on experience. The tagging method selects 5 to 10 tea trees, and selects 5 to 10 axillary buds for each plant to tag for observation to determine the budding period. Under the same conditions, those whose germination period is more than 5 days earlier than that of Fuding Dabai tea varieties are extra-early varieties, those whose germination period is less than 4 days earlier than those of Fuding Dabai tea varieties are early-germination varieties, those whose germination period is less than 5 days later than those of Fuding Dabai tea varieties are meso-germination varieties, and those whose germination period is more than 5 days later are mid-germination varieties. It is a late-growing variety. Tea tree varieties can be divided into four categories according to the size of mature leaves: extra large leaf varieties, large leaf varieties, medium leaf varieties and small leaf varieties. Leaf size is compared by measuring leaf area (leaf length × leaf width × 0.7). A leaf area of ??more than 70cm2 is an extra-large leaf variety, a leaf area between 40 and 69cm2 is a large-leaf variety, and a leaf area between 21 and 39cm2 is a large-leaf variety. Medium-leaf varieties, small-leaf varieties with a leaf area of ??less than 20cm2. Tea tree varieties can be divided into high-yielding varieties and general varieties according to their yield. The identification of yield requires that it be carried out under the same cultivation and management conditions. Pick fresh leaves according to the picking standards to record the yield. Record the yield repeatedly for three years to calculate the average and convert it into the yield per unit area. You can also divide the fresh leaf yield by 4 and convert it into dry tea yield. . When counting output, green tea or black tea varieties are picked based on the standard of one bud and two or three leaves to record the yield. Oolong tea varieties are based on new shoots that have grown to 3 to 5 leaves. When about 70 top leaves form an open surface, pick two or three leaves. Record the output. Tea tree varieties are divided into four categories according to tea adaptability: green tea varieties, black tea varieties, black and green tea varieties and oolong tea varieties. Among them, green tea varieties are further divided into millimeter-type green tea varieties and less millimeter-type Longjing type flat green tea varieties. The so-called adaptability of tea refers to the inherent characteristics of the variety that restrict the quality of tea. It also refers to the characteristics of the tea tree variety that is most suitable for making one or several types of high-quality tea. The tea adaptability of tea tree varieties is referred to as adaptability. It can be indirectly evaluated through the observation of physical properties of buds and leaves and the measurement of chemical properties. This is especially commonly used in the early stages of tea tree variety selection. Physical characteristics refer to the fatness, size, leaf color, leaf quality, leaf thickness, softness, tenderness, hairiness, etc. of the buds and leaves on the new shoots of the tea tree. They are closely related to the appearance and quality of the finished tea.

Generally, varieties with small leaves, thick leaves, soft, delicate leaves, green color and many hairs can easily create the appearance of "pekoe-covered green tea", such as Maofeng, Maojian, Yinya and other famous teas. The quality characteristics of "silver-coated"; varieties with slender buds and leaves, yellow-green or light green leaves, and less or medium-to-medium hairs, such as longjing flat green tea, such as Longjing tea and other famous teas, are easy to form The appearance is flat and smooth, tall and pointed, green in color, and hairless on the body; the leaves are large, the internodes are long, the buds are fat, the buds and leaves are yellow-green, hairy, the leaves are raised, the leaves are soft, and the leaves are open. The thin variety produces better black tea quality. Chemical properties refer to the content and composition of chemical components in buds and leaves, which are the material basis for the color, aroma, and flavor of tea. For the determination of chemical properties, fresh leaves are generally collected according to the standard of one bud and three leaves, steamed at 100°C for 3 minutes, and dried at 80°C to prepare steamed green tea samples, and then ground the samples for chemical composition determination. Although the chemical properties of tea tree varieties are greatly affected by the environment and cultivation conditions of the planting area, the differences in chemical properties between different varieties under the same conditions are still obvious. Generally, varieties with high tea polyphenols content and a large ratio of tea polyphenols to amino acids (referred to as the phenolic amino acid ratio) have excellent black tea quality; while high amino acid content, appropriate tea polyphenol content (about 16 to 24), and phenolic amino acid ratio are high. Compared with small varieties, the quality of green tea produced is superior. For example, Qianmei 419 variety, steamed green tea contains tea polyphenols 36.03, amino acids 1.4, phenolic to amino acid ratio 25.7. The prepared black tea soup is red and bright, has a strong aroma, and has a strong taste, but the prepared green tea has a strong and bitter taste, indicating that Qianmei 419 is An excellent variety suitable for making black tea. After Fuding Dabai tea was introduced to Meitan, steamed green tea in spring and summer contains an average of 25.3 tea polyphenols, 1.89 amino acids, and a phenolic-to-amino acid ratio of 13.4. The multi-millilitous green tea has a green appearance and a long-lasting chestnut aroma, but the black tea tastes The thinness shows that Fuding Dabai Tea is an excellent variety suitable for hair-showing green tea. In production, the adaptability of tea tree varieties is generally directly identified by making different types of tea leaves from the same variety of fresh leaves and conducting sensory evaluation. When sensory evaluation is used to identify quality, a method of combining scoring and commenting is adopted. First, accurately weigh 3 grams of tea sample and pour it into the evaluation cup, then pour in about 150 ml of boiling water, and soak for 5 minutes to start the evaluation. According to the five-factor evaluation method, the quality of tea is scored on a percentage scale based on appearance, soup color, aroma, taste, and leaf base, and described with corresponding comments. Finally, the quality of tea is divided into three categories: appearance, soup color, aroma, taste, and leaf base. The weights are used to calculate the total score. Among them, famous green tea is calculated based on the quality weights of appearance 30, soup color 10, aroma 25, taste 25, and leaf base 10. The level of the score can directly reflect the quality of the variety, that is, the adaptability of a variety to a certain tea type, and the corresponding comments can describe the tea quality characteristics of different varieties. Since different tea types have different quality requirements, and the inherent adaptability of each variety restricts the quality of tea, and the adaptability differences between different varieties are large, the variety suitable for green tea may not necessarily be suitable for black tea. The varieties of green tea with a thicker shape are not suitable for making flat green tea with a thinner shape. Therefore, the adaptability of tea tree varieties should be one of the key indicators to consider in production. Only by selecting tea tree varieties with the right adaptability can we produce corresponding high-quality tea products. Tea tree varieties can be divided into national-level varieties and provincial-level varieties according to the approval department. After a newly developed variety has been identified for its germination period, stress resistance, yield, adaptability, etc., it must finally pass the approval of the provincial or national crop variety approval committee before it is allowed to be promoted and applied in large areas in production. The standards for the approval of national tea tree varieties are excerpted below to provide an overall understanding of national tea tree varieties. There are three standards for this, and those that meet one of them can be certified as national tea tree varieties. ① The yield in the regional trial is more than 10% higher than that of the control variety, and reaches the significant standard through statistical analysis; ② The yield is similar to the control variety, and the quality is significantly better than the control variety; ③ Some traits are outstanding and have special utilization value, and the yield and quality are equivalent to the control variety .