Hot-air full drying driven metabolome changes in white tea (Camellia sinensis L.)

ABSTRACT

White tea (Camillia sinensis L.) is the least processed tea, and due to simpler processing steps involved, its flavor and nutritive compound composition is least disturbed. However, only a limited number of research has explored the key metabolomic changes during white tea processing (especially drying). The freshly harvested leaves of C. sinensis var. Tieguanyin were initially withered at room temperature for 72 h, and first-dried on fire at 70°C for 3 h. Then, they were spread at room temperature for 7 days and fully dried at 80°C for 4 h, followed by cooled at room temperature. The metabolome of the tea leaves before (CK) and after full drying (RO) were compared using UPLC-MS/MS. The LC-MS/MS analysis identified 1,253 compounds belonging to 11 classes. The highest number of accumulated compounds belonged to flavonoids, phenolic acids, and lipids. Of the 57 differentially accumulated metabolites (DAMs), 49 were up-accumulated in RO. These were classified as amino acids derivatives, lipids, organic acids, vitamins, alkaloids, nucleotides and derivatives, flavonoids, tannins, terpenoids, lignans and coumarins. We found that several health beneficial compounds showed up-accumulation in RO compared to CK. We concluded that Hot-air full drying alters white team metabolome composition.

KEYWORDS:

• Amino acid derivatives
• flavonoids
• phenolic acids
• tea roasting
• terpenoids
• white-tea processing

Acknowledgement

Funding from Fujian Science and Technology Department is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Y.X. contributed to the total administration or supervision of the research project, and Y.X. and J.H.L. contributed to the conception and design; W.H.L. contributed to the supplement of white tea raw materials. J.Y.Z., Y.J.H., W.H.L and X.S. contributed to acquisition of literature, investigation and analysis of the data; Y.X. and Y.P.H. contributed to the interpretation of the data; Y.X., J.Y.Z., and Y.J.H. drafted or revised the manuscript. All authors have read and agreed to the published version of the manuscript.

Data availability statement

The datasets generated for this study are either presented as the main figures/tables or supplementary files.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10942912.2023.2254948

Additional information

Funding

This study was supported by the Spark Project (no. 2021S0063) from Fujian Science and Technology Department.