Tea varieties and theabrownin content basis
There are significant differences in processing technology and raw material characteristics between different tea varieties, which directly leads to differences in theabrownin content. For example, dark tea has undergone the Wodui fermentation process, and its theabrownin content is relatively high, reaching 6%-10% of the dry weight of the tea. Since green tea is not fermented, the theabrownin content is very small, generally less than 0.5%. Black tea is fermented and has a medium theabrownin content, about 2%-5%.
Influence of raw material factors
The maturity and growth environment of tea raw materials play an important role in the content of theabrownin. Tea leaves with high maturity have a higher degree of internal material transformation and are more likely to produce theabrownin during processing. Tea grown in a high-altitude, cloud-shrouded environment is rich in substances. Under certain processing techniques, the amount of theabrownin produced may be different from that of tea from low-altitude areas. For example, Pu'er tea made from high-altitude Yunnan large-leaf tea leaves has unique theabrownin content due to the characteristics of its raw materials.
The role of processing technology links
All aspects of the processing process have a huge impact on the formation of theabrownin. For example, when black tea is piled up, microorganisms multiply and participate in material metabolism. Tea polyphenols and other substances are oxidized and polymerized to form theabrownin. During the fermentation process of black tea, the enzymatic oxidation reaction in tea cells gradually converts tea polyphenols into theabrownin and other substances. During green tea processing, killing quickly inhibits enzyme activity and reduces the production of theabrownin.
Effect of storage conditions
Tea storage time and conditions can also change theabrownin content. As the storage time increases, tea polyphenols and other substances in tea will slowly oxidize, and theabrownin content will gradually increase. For example, after several years of storage under suitable storage conditions, the theabrownin content of Pu'er tea will increase significantly, and the soup color will become redder and richer. The temperature, humidity and oxygen content of the storage environment will affect the oxidation rate and thus the accumulation of theabrownin.
Detection methods and accuracy
Accurate determination of theabrownin content relies on scientific detection methods. Currently commonly used spectrophotometry, high performance liquid chromatography, etc. each have their own advantages and disadvantages. Spectrophotometry is easy to operate, but may be interfered by other substances; high-performance liquid chromatography is highly accurate, but the equipment is expensive and the operation is complex. The choice of different detection methods will affect the determination results of theabrownin content, thereby affecting the judgment of the differences in theabrownin content in different varieties of tea.
Theabrownin content difference and quality correlation
The difference in theabrownin content is closely related to the quality of tea. In dark tea, the appropriate amount of theabrownin gives the tea soup a mellow taste and a bright red color, which is a sign of good quality. However, excessive theabrownin content may cause the tea soup to become bitter and astringent and have a weak taste. In green tea, low theabrownin content can maintain the quality characteristics of green leaves in clear soup. Therefore, understanding the differences in theabrownin content will help regulate and evaluate tea quality.
Research significance and prospects
Exploring the content differences and influencing factors of theabrownin in different tea varieties is of great significance for in-depth understanding of the formation mechanism of tea quality, optimization of tea processing technology, and rational utilization of tea resources. In the future, with the continuous development of technology, it is expected to further clarify the precise relationship between theabrownin and tea quality, develop more precise processing technology control methods, and promote the innovative development of the tea industry.
