基于非靶向代谢组学的信阳毛尖茶加工过程非挥发物代谢轮廓分析

Metabolic Profiling of Non-volatile Compounds during Xinyang Maojian Tea Processing Using Untargeted Metabolomics

为了解信阳毛尖茶在加工过程中非挥发性代谢物的变化规律,以信阳群体种鲜叶为原料,采用非靶向代谢组学技术对信阳毛尖茶加工过程样品进行系统分析。结果显示,在信阳毛尖茶加工过程中共对比鉴定出1000种非挥发性代谢物,多元统计分析表明信阳毛尖茶在杀青后其非挥发性代谢物发生显著变化;同时共筛选出53个差异化合物,其中氨基酸、儿茶素、黄酮糖苷、脂质、嘌呤核苷、有机酸等化合物的转化是形成信阳毛尖茶风味和品质的关键;尤其是一些酰化黄酮糖苷、溶血磷脂酰类、嘌呤核苷类化合物在杀青后相对含量显著提升;京都基因与基因组百科全书代谢通路富集分析结果显示,差异化合物在嘌呤代谢,甘油磷脂代谢,苯丙氨酸代谢,氨酰基-tRNA生物合成,苯丙氨酸、酪氨酸和色氨酸生物合成和甘氨酸、丝氨酸和苏氨酸代谢这些代谢通路中显著富集(P<0.05)。本研究进一步挖掘了影响信阳毛尖茶风味和品质的主要非挥发性代谢物,为揭示信阳毛尖茶风味和品质形成机制提供依据和参考。

In order to understand the dynamic changes of non-volatile metabolites in Xinyang Maojian tea during processing,Xinyang Maojian tea samples from Xinyang tea population(Camellia sinensis cv.Quntizhong)taken during processing were systematically analyzed by non-targeted metabolomics.A total of 1000 non-volatile metabolites were identified,and multivariate statistical analysis showed that non-volatile metabolites changed significantly during the processing stages after fixation.Meanwhile,a total of 53 differential compounds were screened out,including amino acids,catechins,flavonoid glycosides,lipids,purine nucleosides and organic acids that were identified as the key components contributing to the flavor and quality of Xinyang Maojian tea.In particular,the relative contents of some acylated flavonoid glycosides,lysophosphatidyls and purine nucleosides were significantly elevated during the processing stages after fixation.Kyoto Encyclopedia of Genes and Genomes(KEGG)metabolic pathway enrichment analysis showed that the differential compounds were significantly enriched in the pathways of purine metabolism,glycerophospholipid metabolism,phenylalanine metabolism,aminoacyl-tRNA biosynthesis,phenylalanine,tyrosine,and tryptophan biosynthesis,and glycine,serine and threonine metabolism(P<0.05).This study provides a basis for understanding the formation mechanism of the flavor and quality of Xinyang Maojian tea.