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Journal of Tea Science ›› 2023, Vol. 43 ›› Issue (1): 124-134.doi: 10.13305/j.cnki.jts.2023.01.009

• Research Paper • Previous Articles     Next Articles

Physicochemical Properties of Tannase in Tea Plants (Camellia sinensis) and Its Application on Green Tea Beverages

CHEN Yifan1, KAN Xinyi1, JIANG Xiaolan1, GAO Liping2,*, XIA Tao1,*   

  1. 1. State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China;
    2. School of Life Science, Anhui Agricultural University, Hefei 230036, China
  • Received:2022-09-16 Revised:2022-12-06 Online:2023-02-15 Published:2023-03-01

Abstract: Galloylated catechins have an important impact on the taste of green tea, but excessive accumulation of galloylated catechins in tea plants in summer and autumn will reduce the sensory quality. A native Camellia sinensis tannase (CsTA) discovered in the previous study has the function of hydrolyzing galloylated catechins. But its physicochemical properties and whether it can play a role in the processing of green tea beverages are not clear. In this article, the CsTA was further studied on the basis of previous experimental results. The results show that the optimal temperature of the enzyme was 45 ℃, the thermal stability range was below 60 ℃, the optimal reaction pH was 7.0. Mg2+ had a significant activation effect on CsTA. Cu2+ could completely inactivate CsTA activity. Mn2+, Zn2+, Al3+, Fe3+, Fe2+ and Li+ had a certain inhibitory effect, and CsTA had a good storage stability after freeze-drying. After applying CsTA to green tea infusion, it was found that the best degradation effect of ester catechins was obtained when the added amount was 11 μg, the ratio of material to liquid was 1∶100, the reaction time was 20 min, and the temperature was 35 ℃. This study would provide a theoretical reference for using CsTA to reduce the bitterness and astringency and improve the quality of green tea processing in the future.

Key words: galloylated catechins, tea tannase, physicochemical properties, the processing of green tea beverages

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