Comparison of volatile and nonvolatile metabolites in green tea under hot-air drying and four heat-conduction drying patterns using widely targeted metabolomics

Zheng Tu; YueYun Liu; JiaZheng Lin; HaoWei Lv; Wei Zhou; XiaoFeng Zhou; YuanFeng Qian; Xu Zeng; WeiZhong He; Yang Ye

doi:10.1016/j.fochx.2023.100767

Comparison of volatile and nonvolatile metabolites in green tea under hot-air drying and four heat-conduction drying patterns using widely targeted metabolomics

Food Chem X. 2023 Jun 24:19:100767. doi: 10.1016/j.fochx.2023.100767. eCollection 2023 Oct 30.

Authors

Zheng Tu¹, YueYun Liu², JiaZheng Lin¹, HaoWei Lv¹, Wei Zhou³, XiaoFeng Zhou⁴, YuanFeng Qian⁵, Xu Zeng², WeiZhong He⁶, Yang Ye¹

Affiliations

¹ Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Hangzhou, Zhejiang 310008, China.
² Yibin Research Institute of Tea Industry, Yibin, Sichuan 644005, China.
³ Tea Industry Development Center of Guiding County, No.47, Hong Road, Guiding, Guizhou 551300, China.
⁴ Technology Service Station of Tea Science, Wuyi, Zhejiang 321200, China.
⁵ Agricultural Bureau of Songyang County, Lishui, Zhejiang 323400, China.
⁶ Lishui Institute of Agriculture and Forestry Sciences, Lishui, Zhejiang 323400, China.

Abstract

Hot-air and heat-conduction drying are the most common drying patterns in green tea production. However, the differences between them in terms of the resulting green tea chemical compounds have not been illustrated systematically. In this study, 515 volatile and 204 nonvolatile metabolites were selected to compare the differences between hot-air drying green tea (HAGT) and four heat-conduction drying green teas (HCDGTs) using widely targeted metabolomics. The results showed notable changes in volatile compounds; for example, two kinds of HCDGTs preferred to form chestnut-like and caramel-like key odorants. In addition, 14 flavonol glycosides, 10 catechins, 9 phenolic acids, 8 amino acids, 7 flavonols, and 3 sugars were significantly changed between HAGT and HCDGTs (p < 0.05), presenting a tremendous discrepancy in the transformation of nonvolatile compounds. Our results provide clear guidance for the precise manufacturing of green tea by four common heat-drying patterns and hot air-drying patterns.

Keywords: Green tea; Heat-conduction drying; Hot-air drying; Nonvolatile metabolites; Volatile metabolites.