Variations in microbial diversity and chemical components of raw dark tea under different relative humidity storage conditions

Wei Xu; Yiqiao Zhao; Yating Lv; Tunyaluk Bouphun; Wenbao Jia; Siyu Liao; Mingzhi Zhu; Yao Zou

doi:10.1016/j.fochx.2023.100863

Variations in microbial diversity and chemical components of raw dark tea under different relative humidity storage conditions

Food Chem X. 2023 Sep 2:19:100863. doi: 10.1016/j.fochx.2023.100863. eCollection 2023 Oct 30.

Authors

Wei Xu¹, Yiqiao Zhao¹, Yating Lv¹, Tunyaluk Bouphun², Wenbao Jia¹, Siyu Liao¹, Mingzhi Zhu³, Yao Zou¹

Affiliations

¹ College of Horticulture, Tea Refining and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.
² Faculty of Science and Agricultural Technology, Rajamangala University of Technology Lanna Lampang, Lampang 52000, Thailand.
³ Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha 410128, China.

Abstract

Raw dark tea (RDT) usually needs to be stored for a long time to improve its quality under suitable relative humidity (RH). However, the impact of RH on tea quality is unclear. In this study, we investigated the metabolites and microbial diversity, and evaluated the sensory quality of RDT stored under three RH conditions (1%, 57%, and 88%). UHPLC-Q-TOF-MS analysis identified 144 metabolites, including catechins, flavonols, phenolic acids, amino acids, and organic acids. 57% RH led to higher levels of O-methylated catechin derivatives, polymerized catechins, and flavonols/flavones when compared to 1% and 88% RH. The best score in sensory evaluation was also obtained by 57% RH. Aspergillus, Gluconobacter, Kluyvera, and Pantoea were identified as the core functional microorganisms in RDT under different RH storage conditions. Overall, the findings provided new insights into the variation of microbial communities and chemical components under different RH storage conditions.

Keywords: Metabolomics; Microbiome; Raw dark tea; Relative humidity; Storage.