Metabolomic Analysis of the Chemical Composition of Chongjue Luohan Tea

To elucidate the chemical material basis of the flavor quality of Chongjue Luohan tea, four representative tea samples (Zifu, Ankang, Ping’an and Jufu teas) were analyzed by sensory evaluation and metabolomics based on ultra-high performance liquid chromatography-quadrupole-mass spectrometry (UPLC-Q-MS). The results showed that Luohan tea contained higher levels of tea polyphenols, ranging from 13.7% to 18.1%, than traditional black tea (9.6%). In addition, a total of 206 secondary metabolites were identified in Luohan tea, including flavonoids (71), amino acids and their derivatives (31), organic acids (24), nucleotides and their derivatives (19), phenolic acids (16), alkaloids (12), and saccharides and their derivatives (7). Multivariate statistical analysis pinpointed 46 differential metabolites. Notably, Zifu and Ankang tea samples contained higher levels of bitter and astringent components, such as flavanols, proanthocyanidins and flavanol glycosides, whereas Ping’an and Jufu tea samples were richer in umami and sweet components, such as L-asparagine and L-theanine. The results of this study provide a reference for research to develop new types of Luohan tea.