Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Food Science, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Southwest University, Chongqing 400715, China; Chongqing Tea Technology and Innovation Center, China.
National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha 410128, China.
Food Res Int. 2024 Oct;193:114857. doi: 10.1016/j.foodres.2024.114857. Epub 2024 Aug 2.
Theacrine, a purine alkaloid derived from Camellia assamica var. kucha, has a distinct bitter taste. Our previous study found the lower recognition threshold of theacrine at 25 °C than 45 °C. This study aims to investigate the bitterness characterizations of theacrine at aforementioned temperatures and its taste perception mechanism. Sensory analysis exhibited higher bitterness intensity for theacrine at 25 °C than 45 °C. Subsequently, flow cytometry was performed to verify the above characterization at the cellular level. It revealed that theacrine could activated the bitter receptor hTAS2R14 and the calcium signal at 25 °C was higher than 45 °C. Ultimately, the interaction mechanism was studied by molecular dynamics simulations, indicating that the conformation of theacrine-hTAS2R14 had a higher binding capacity and better stability at 25 °C. Overall, temperature affected the binding of theacrine to the bitter receptor hTAS2R14, resulting in the stronger bitterness intensity of theacrine at 25 °C than 45 °C.
可可因，一种从茶树变种库卡中提取的嘌呤生物碱，具有独特的苦味。我们之前的研究发现，可可因在 25°C 时的识别阈值低于 45°C。本研究旨在探究可可因在上述温度下的苦味特征及其味觉感知机制。感官分析表明，可可因在 25°C 时的苦味强度高于 45°C。随后，通过流式细胞术在细胞水平上验证了上述特征。结果表明，可可因可以激活苦味受体 hTAS2R14，并且在 25°C 时的钙信号高于 45°C。最终，通过分子动力学模拟研究了相互作用机制，表明在 25°C 时，可可因-hTAS2R14 的构象具有更高的结合能力和更好的稳定性。总的来说，温度影响可可因与苦味受体 hTAS2R14 的结合，导致可可因在 25°C 时的苦味强度强于 45°C。
