Welcome to Journal of Tea Science,Today is

Journal of Tea Science ›› 2023, Vol. 43 ›› Issue (4): 553-566.doi: 10.13305/j.cnki.jts.2023.04.007

• Research Paper • Previous Articles     Next Articles

Changes in Chemical Composition of Zijuan Tea under Anaerobic Treatment Conditions and Their Effects on in vitro ACE Activity

YANG Gaozhong1,2, SHI Jiang1, ZHANG Yue1, PENG Qunhua1, LIN Zhi1,*, LÜ Haipeng1,*   

  1. 1. Tea Research Institute of the Chinese Academy of Agricultural Science/Key Laboratory of Biology, Genetics and Breeding of SpecialEconomic Animals and Plants, Ministry of Agriculture and Rural Affairs, Hangzhou 310008, China;
    2. Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • Received:2023-04-17 Revised:2023-05-14 Online:2023-08-15 Published:2023-08-24

Abstract: In this study, fresh leaves of Zijuan tea were treated with anaerobic treatment and used to make freeze-dried, green, black and white tea samples. The main non-volatile components (such as catechins, amino acids, anthocyanins) in these samples were determined and their in vitro angiotensin-converting enzyme (ACE) inhibitory activities were evaluated by high performance liquid chromatography. In addition, molecular docking simulation experiments were conducted to investigate the potential interaction mechanisms between the major chemical components in tea and ACE. The results show that the GABA content in the freeze-dried samples after anaerobic treatment increased to 1.72 mg·g-1, which was significantly higher than that in the tea samples without anaerobic treatment (0.04 mg·g-1, P<0.05). The composition and contents of amino acids and polyphenolic compounds in the tea samples were significantly affected by the processing methods after anaerobic treatment. The white tea process could increase the contents of amino acid components in the tea samples, while the freeze-drying process could maximize the retention of polyphenolic compounds in the tea samples. The in vitro ACE inhibitory activity of Zijuan tea fresh leaf samples was significantly enhanced after anaerobic treatment (P<0.05); the strongest ACE activity inhibition was observed in samples prepared by freeze-drying process after anaerobic treatment, which was significantly higher than that of samples prepared by green, white, and black tea processing methods (P<0.05). In addition, molecular docking simulation experiments reveal that the strength of the interaction between the main chemical components in tea and ACE was related to the hydrophilic groups and aromatic ring structures in their molecular structures. The results of the study helped to reveal the effect of anaerobic treatment on the ACE inhibitory activity of Zijuan tea and provided a theoretical basis for the development of special functional Zijuan tea products with potential treatment of hypertension.

Key words: tea, γ-aminobutyric acid, anaerobic treatment, processing technology, angiotensin-converting enzyme

CLC Number: