Bitterness quantification and simulated taste mechanism of theasinensin A from tea

• Published in: Frontiers in nutrition (Lausanne) Vol. 10; p. 1138023
• Main Authors: Zhang, Jian-Yong, Cui, Hong-Chun, Feng, Zhi-Hui, Wang, Wei-Wei, Zhao, Yun, Deng, Yu-Liang, Jiang, He-Yuan, Yin, Jun-Feng, Engelhardt, Ulrich H
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 09.05.2023
• Subjects: bitterness; molecular docking; Nutrition; tea; theasinensin A; threshold; theasinensin A; tea; threshold; molecular docking; bitterness
• ISSN: 2296-861X; 2296-861X
• DOI: 10.3389/fnut.2023.1138023

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.