College of Life Science, Xinyang Normal University, 237 Nanhu R., Xinyang, 464000, Henan, People's Republic of China.
State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, 230036, Anhui, People's Republic of China.
Sci Rep. 2024 May 7;14(1):10424. doi: 10.1038/s41598-024-60951-5.
The storage process has a significant impact on tea quality. Few is known about effect of storage on quality of oolong tea. This study aimed to assess the effect of different storage times on the key chemical components of oolong tea by measuring changes in catechin, free amino acid, and alkaloid content. Variation in the main substances was determined by principal component analysis and heat map analysis. The results revealed notable effects of the storage process on the levels of theanine, epigallocatechin gallate (EGCG), and glutamine. These findings suggest that these compounds could serve as indicators for monitoring changes in oolong tea quality during storage. Additionally, the study observed an increase in the antibacterial ability of tea over time. Correlation analysis indicated that the antibacterial ability against Micrococcus tetragenus and Escherichia coli was influenced by metabolites such as aspartic acid, threonine, serine, gamma-aminobutyric acid, ornithine, alanine, arginine, and EGCG. Overall, this study presents an approach for identifying key metabolites to monitor tea quality effectively with relatively limited data.
贮藏过程对茶叶品质有重要影响。关于贮藏对乌龙茶品质的影响知之甚少。本研究旨在通过测量儿茶素、游离氨基酸和生物碱含量的变化，评估不同贮藏时间对乌龙茶主要化学成分的影响。主要物质的变化通过主成分分析和热图分析来确定。结果表明，贮藏过程对茶氨酸、表没食子儿茶素没食子酸酯（EGCG）和谷氨酰胺的水平有显著影响。这些发现表明，这些化合物可以作为监测乌龙茶在贮藏过程中品质变化的指标。此外，研究还观察到茶叶的抗菌能力随着时间的推移而增强。相关分析表明，对微球菌和大肠杆菌的抗菌能力受天冬氨酸、苏氨酸、丝氨酸、γ-氨基丁酸、鸟氨酸、丙氨酸、精氨酸和 EGCG 等代谢物的影响。总的来说，本研究提出了一种方法，通过相对有限的数据，识别出关键代谢物来有效监测茶叶品质。
