Multidimensional exploration of the bitterness amelioration effect of roasting on Wuyi Rock tea

Weiying Su; Li Ni; Yizhe Chen; Daoliang Wang; Chih-Cheng Lin; Yuan Liu; Zhibin Liu

doi:10.1016/j.foodchem.2023.137954

Multidimensional exploration of the bitterness amelioration effect of roasting on Wuyi Rock tea

Food Chem. 2024 Mar 30;437(Pt 2):137954. doi: 10.1016/j.foodchem.2023.137954. Epub 2023 Nov 7.

Authors

Weiying Su¹, Li Ni², Yizhe Chen³, Daoliang Wang¹, Chih-Cheng Lin⁴, Yuan Liu⁵, Zhibin Liu⁶

Affiliations

¹ College of Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350108, China; Institute of Food Science & Technology, Fuzhou University, Fuzhou, Fujian 350108, China.
² College of Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350108, China; Institute of Food Science & Technology, Fuzhou University, Fuzhou, Fujian 350108, China. Electronic address: nili@fzu.edu.cn.
³ Institute of Food Science & Technology, Fuzhou University, Fuzhou, Fujian 350108, China.
⁴ Department of Biotechnology and Pharmaceutical Technology, Yuanpei University of Medical Technology, Hsinchu, Taiwan, Province of China, China.
⁵ Department of Food Science & Technology, School of Agriculture & Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
⁶ Institute of Food Science & Technology, Fuzhou University, Fuzhou, Fujian 350108, China. Electronic address: liuzhibin@fzu.edu.cn.

PMID: 37952394
DOI: 10.1016/j.foodchem.2023.137954

Abstract

The influence of roasting on tea bitterness remains unclear. With Wuyi Rock tea (WRT) as an example, this study investigated the impact of roasting on WRT's bitterness, utilizing an integrated approach involving sensory evaluation, bitter compound profiling, and cell-based calcium imaging. Sensory analysis revealed that roasting effectively reduced the perceived bitterness of WRT. This reduction was supported by decreases in various bitter compounds, including 19 flavanols, 11 flavonols, 12 phenolic acids, 2 purine alkaloids, and 9 bitter amino acids, which diminished by 16%, 26%, 19%, 2%, and 70%, respectively. Furthermore, we established two heterogeneous bitter receptor expression systems: TAS2R39/Gα15-HEK293T and TAS2R14/Gα15-HEK293T cell lines. These systems quantitatively confirmed the reduction in bitterness, demonstrating 51% and 62% decreases in intracellular calcium mobilization within the transfected cells, respectively. These findings provide compelling evidence for the bitterness-ameliorating effect of roasting, expanding our knowledge of the role of roasting in shaping the flavor of tea.

Keywords: Bitterness; Calcium imaging; Roasting; TAS2Rs; Tea.

MeSH terms

Alkaloids*
Calcium*
HEK293 Cells
Humans
Receptors, Cell Surface
Taste
Tea / chemistry

Substances

Calcium
Alkaloids
Tea
TAS2R39 protein, human
Receptors, Cell Surface