Bitterness quantification and simulated taste mechanism of theasinensin A from tea

Jian-Yong Zhang; Hong-Chun Cui; Zhi-Hui Feng; Wei-Wei Wang; Yun Zhao; Yu-Liang Deng; He-Yuan Jiang; Jun-Feng Yin; Ulrich H Engelhardt

doi:10.3389/fnut.2023.1138023

Bitterness quantification and simulated taste mechanism of theasinensin A from tea

Front Nutr. 2023 May 9:10:1138023. doi: 10.3389/fnut.2023.1138023. eCollection 2023.

Authors

Affiliations

¹ Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
² Tea Research Institute of Hangzhou Academy of Agricultural Science, Hangzhou, China.
³ Institute of Food Chemistry, Brunswick University of Technology, Braunschweig, Germany.

^# Contributed equally.

Abstract

Theasinensin A is an important quality chemical component in tea, but its taste characteristics and the related mechanism are still unclear. The bitterness quantification and simulated taste mechanism of theasinensin A were researched. The results showed that theasinensin A was significantly correlated with the bitterness of tea. The bitterness threshold of theasinensin A was identified as 65 μmol/L for the first time. The dose-over-threshold (DOT) value of theasinensin A was significantly higher than that of caffeine in black tea soup. The concentration-bitterness curve and time-intensity curve of theasinensin A were constructed. The bitterness contribution of theasinensin A in black tea was higher than in oolong and green tea. Theasinensin A had the highest affinity with bitterness receptor protein TAS2R16, which was compared to TAS2R13 and TAS2R14. Theasinensin A was mainly bound to a half-open cavity at the N-terminal of TAS2R13, TAS2R14, and TAS2R16. The different binding capacity, hydrogen bond, and hydrophobic accumulation effect of theasinensin A and bitterness receptor proteins might be the reason why theasinensin A presented different bitterness senses in human oral cavity.

Keywords: bitterness; molecular docking; tea; theasinensin A; threshold.

Grants and funding

This study was funded by the China National Key Research and Development Program (2021YFD1601105), the China Zhejiang Key Research and Development Program (2022C02033), the China Hangzhou Agricultural and Social Development Scientific Research Key Project (202203A06), the China Agriculture Research System of MOF and MARA (CARS-19), and the Innovation Project for Chinese Academy of Agricultural Sciences.