Dynamic Variation of Amino Acid Contents and Identification of Sterols in Xinyang Mao Jian Green Tea |
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| Authors: | Meng Sun Fangfang Yang Wanying Hou Shuangfeng Jiang Runqi Yang Wei Zhang Mingjie Chen Yuhang Yan Yuxin Tian Hongyu Yuan |
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| Affiliation: | 1.Henan Key Laboratory of Tea Plant Biology, College of Life Sciences, Xinyang Normal University, Xinyang 464000, China; (M.S.); (W.H.); (S.J.); (R.Y.); (W.Z.); (M.C.); (Y.Y.); (Y.T.);2.Guangxi-ASEAN Food Inspection and Testing Center, Nanning 530029, China;3.Xinyang Academy of Agricultural Sciences, Xinyang 464000, China |
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| Abstract: | As important biomolecules in Camellia sinensis L., amino acids (AAs) are considered to contribute to the overall green tea sensory quality and undergo dynamic changes during growth. However, limited by analytical capacity, detailed AAs composition in different growth stages remains unclear. To address this question, we analyzed the dynamic changes of 23 AAs during leaf growth in Xinyang Mao Jian (XYMJ) green tea. Using amino acid analyzer, we demonstrated that most AAs are abundant on Pure Brightness Day and Grain Rain Day. After Grain Rain, 23 AAs decreased significantly. Further analysis shows that theanine has a high level on the day before Spring Equinox and Grain Rain, accounting for 44–61% of the total free AAs content in tea leaves. Glu, Pro, and Asp are the second most abundant AAs. Additionally, spinasterol and 22,23-dihydrospinasterol are first purified and identified in ethanol extract of XYMJ by silica gel column chromatography method. This study reveals the relationship between plucking days and the dynamic changes of AAs during the growth stage and proves the rationality of the traditional plucking days of XYMJ green tea. |
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| Keywords: | Xinyang Mao Jian amino acids dynamic contents sterols growth process |
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