基于非靶向代谢组学的六垌茶关键特征成分分析

Non-targeted Metabolomics Analysis of Key Characteristic Components in Liudong Tea

本研究以广西地区的特色茶叶六垌茶为对象,采用非靶向代谢组学方法,联合化学计量学分析识别不同加工工艺、采摘时间和种植模式的六垌茶特征成分,探究不同因素对特征成分的影响。共识别筛选出六垌茶的23个不同关键特征成分,包括(+)-没食子儿茶素、茶黄素-3-没食子酸酯等,其中儿茶素及其衍生物和黄酮类化合物占特征成分的主导地位,数量占比达82.6%。区分不同加工工艺和采摘时间六垌茶具有最大变量投影重要性(variable importance in projection,VIP)值的特征成分均为萜烯类及其衍生物,分别为阿库米尼苷和桧烯的同分异构体,不同种植模式六垌茶中最大VIP值特征成分为(+)-儿茶素。结果表明,在不同加工工艺、采摘时间和种植模式等因素影响下,六垌茶的关键特征成分及其含量分布不同。其中,红茶工艺促进茶黄素-3-没食子酸酯的形成和萜烯糖苷的水解;随采摘时间的延长,六垌茶中山柰酚-3-O-对香豆酰基鼠李糖葡萄糖苷等5个黄酮类特征成分的相对丰度升高;人工种植降低了(+)-儿茶素等儿茶素及其衍生物特征成分的相对丰度。本研究基于非靶向代谢组学识别不同六垌茶的关键特征成分及丰度差异,有助于探索不同六垌茶特征品质形成的机理机制,可为六垌茶的加工工艺和栽培技术等品质调控提升提供科学依据。

This study employed non-targeted metabolomics combined with chemometrics to investigate the effects of different manufacturing processes,harvest times and cultivation methods on the key characteristic components of Liudong tea,a specialty tea cultivar from Guangxi.A total of 23 key components were identified,including(+)-gallocatechin and theaflavinmonogallates.Among them,catechins and their derivatives,as well as flavonoids,predominated,accounting for 82.6%of the total.The key characteristic components with the highest variable importance in the projection(VIP)values for distinguishing Liudong tea from different processing methods and harvest times were terpenes and their derivatives,namely acuminoside@RT 9.77 and(+/-)-sabinene@RT 10.11,while that for distinguishing Liudong tea from different cultivation methods was(+)-catechin.The results indicated that different processing methods,harvest times and cultivation patterns significantly influenced the key characteristic components and their content distribution in Liudong tea.The black tea processing method promoted the formation of theaflavinmonogallates and the hydrolysis of terpenoid glycosides.The later the harvest date,the higher the relative abundance of five key flavonoid components,including kaempferol-3-O-(6’’’-trans-p-coumaroyl-2’’-glucosyl)rhamnoside.Artificial cultivation reduced the relative abundance of some key characteristic components including catechins such as(+)-catechin and their derivatives.This study contributes to understanding the mechanisms underlying the formation of the characteristic quality of different Liudong tea,thereby providing a scientific basis for improving the cultivation techniques and processing methods for the quality control of Liudong tea.