From heat to flavor: Unlocking new chemical signatures to discriminate Wuyi rock tea under light and moderate roasting

Yifei Peng; Zhenghua Du; Xiaxia Wang; Ruimei Wu; Chao Zheng; Wenbo Han; Li Liu; Feng Gao; Guoying Liu; Baoshun Liu; Zhilong Hao; Xiaomin Yu

doi:10.1016/j.foodchem.2023.137148

From heat to flavor: Unlocking new chemical signatures to discriminate Wuyi rock tea under light and moderate roasting

Food Chem. 2024 Jan 15:431:137148. doi: 10.1016/j.foodchem.2023.137148. Epub 2023 Aug 15.

Authors

Yifei Peng¹, Zhenghua Du², Xiaxia Wang³, Ruimei Wu³, Chao Zheng³, Wenbo Han³, Li Liu¹, Feng Gao⁴, Guoying Liu⁵, Baoshun Liu⁶, Zhilong Hao⁷, Xiaomin Yu⁸

Affiliations

¹ College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Center for Plant Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
² Center for Plant Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
³ Center for Plant Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
⁴ Fujian Farming Technology Extension Center, Fuzhou 350003, China.
⁵ Wuyishan Institute of Agricultural Sciences, Wuyishan 354300, China.
⁶ Wuyishan Tea Bureau, Wuyishan 354300, China.
⁷ College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: haozhilong@126.com.
⁸ Center for Plant Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: xmyu0616@fafu.edu.cn.

PMID: 37598651
DOI: 10.1016/j.foodchem.2023.137148

Abstract

Roasting is crucial for the distinct flavor of Wuyi rock tea (WRT). This study applied untargeted metabolomics to investigate the effects of roasting on 139 WRT samples roasted at light fire (LF) or moderate fire (MF) intensities. Compared to LF, MF roasting led to a decrease in the cis/trans flavanol ratio by 56% and theanine by 85%, while increasing the levels of N-ethyl-2-pyrrolidione-substituted flavanols (EPSFs), flavonol aglycones and flavone C-glycosides. Two new roast markers, 3-p-coumaroyl 1,5-lactone and 4-p-coumaroyl 1,5-lactone, were identified in WRT and their formation increased with roasting temperature. MF roasting facilitated the formation of diverse heterocycles (e.g., pyrazines) and aldehydes (e.g., (Z)-4-heptenal and (E,E)-2.4-decadienal) that contributed to the augmented roasted and fatty odors in WRT. Additionally, the Maillard product furfuryl methyl ether was solely detected in MF samples. These findings provide novel insights into roast markers in WRT with implications for improving quality control measures during tea roasting.

Keywords: Chlorogenic acid lactones; Flavonoids; Metabolomics; Tea roasting; Volatile compounds; Wuyi rock tea.

MeSH terms

Hot Temperature*
Lactones*
Polyphenols
Tea
Temperature

Substances

furfuryl ethyl ether
Lactones
Polyphenols
Tea