Abstract:
Objective Differentiations in the main chemicals related to quality of spring, summer, and autumn Jinmudan teas were analyzed to examine the correlations between metabolites and characteristics of the teas.
Methods Black, oolong, yellow, white, and green Jinmudan teas made of fresh leaves plucked separately in three seasons were analyzed for biochemical composition using the conventional methods, high performance liquid chromatography, and AQC derivative liquid chromatography tandem triple quadrupole mass spectrometry.
Results The contents of tea polyphenols and catechins in the Jinmudan summer tea were significantly higher than those in the others, whereas that of amino acids highest in the spring tea and lowest in the summer tea. The catechins in the Jinmudan teas were mainly EGC, EGCG, ECG, and GC. Significant correlation between characteristic metabolites in different tea seasons. As analyzed by the OPLS-DA discriminant model, 12 differential metabolites came from the black tea, 15 from the oolong tea, 15 from the white tea, 17 from the yellow tea, and 17 from the green tea. These metabolites were distinctive enough to serve as markers to separate these teas.
Conclusion The chemical differences among the varieties of spring, summer, and autumn Jinmudan teas underscored a close relationship between the chemistry and quality characteristics of the teas.
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