不同等级普安红茶的成分差异及其品质特征

Composition differences and quality characteristics of Pu’an black tea with different grades

中文关键词:  普安红茶  高分辨质谱法  非靶向代谢组学  主成分分析  差异化合物  电感耦合等离子体质谱法

英文关键词:Pu’an black tea  high resolution mass spectrometry  non-targeted metabonomics  principal component analysis  differential compounds  inductively coupled plasma mass spectrometry

中文摘要:

      目的 探索与不同等级普安红茶品质相关的差异化合物。方法 运用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography Q-Exactive Orbitrap high resolution mass spectrometry, UPLC-Q-Orbitrap-HRMS)对普安红茶的非挥发性代谢物进行非靶向代谢组学分析, 使用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)对普安红茶进行矿质元素检测分析, 结合主成分分析(principal component analysis, PCA)等多元统计分析方法, 寻找不同等级茶叶间的差异化合物。结果 PCA可以有效区分不同等级的普安红茶, 且高等级与低等级间的茶叶成分差异较为显著。根据差异倍数(fold change)、变量影响投影(variable importance in projection, VIP)的筛选条件(|log2FC|>1, VIP>1, P<0.05)筛选出不同等级茶叶间的22种差异化合物, 结合热图分析发现, 氨基酸及其衍生物及黄酮类化合物是不同等级茶叶间的主要差异化合物。且矿质元素分析显示, P、Zn、Ca、Na、Fe、Cu和Sr是普安红不同等级茶叶间的主要差异元素。结论 利用非靶向代谢组学和元素分析能够得到与普安红茶等级相关的差异物质, 可作为不同等级间的茶叶进行区分的可行性办法。

英文摘要:

      Objective To explore the differential compounds related to the quality of different grades of Pu’an black tea. Methods Non-targeted metabonomics analysis for the non-volatile tea metabolite of Pu’an black tea was performed by ultra performance liquid chromatography Q-Exactive Orbitrap high resolution mass spectrometry (UPLC-Q-Orbitrap-HRMS), and inductively coupled plasma mass spectrometry (ICP-MS) was used to detect and analyze mineral elements in Pu’an black tea, multivariate statistical analysis methods such as principal component analysis (PCA) were used to find differential compounds between different grades of tea. Results PCA could effectively distinguish different grades of Pu’an black tea, and the difference of Pu’an black tea between high-grade and low-grade was more significant. Twenty-two kinds of differential compounds among the different grades of Pu’an black tea were screened out according to screening conditions of fold change (FC) and variable importance in projection (VIP) (VIP>1, P<0.05 and |Log2FC|>1), combined with heatmap analysis, it was found that amino acids and their derivatives and flavonoids were the main differential compounds between different grades of tea. And mineral elemental analysis showed that the main differential elements between different grades of Pu’an black tea were P, Zn, Ca, Na, Fe, Cu and Sr. Conclusion Differential substances associated with Pu’an black tea grades can be obtained by non-targeted metabolomics and elemental analysis , which can be used as a feasible method to distinguish teas of different grades.