College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; Jinshan College, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; FAFU-UCR Joint Center/Horticultural Plant Biology and Metabolomics Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
Anxi College of Tea Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
Food Chem. 2019 Mar 30;277:289-297. doi: 10.1016/j.foodchem.2018.10.113. Epub 2018 Oct 24.
So far, the chemical quality of different grades of white tea has largely remained unexplored. The objective of this study was to establish a model for quality evaluation of different grades of Bai Mudan white tea. We applied non-targeted ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry in combination with multivariate analysis and analyzed four different grades of Bai Mudan white tea. We found that the metabolite composition from the super-grade and the first-grade shared higher similarity compared to the second-grade or the third-grade white tea, and the Partial Least Square-Discriminant Analysis model showed high capability to explain the sample variation (R2Y = 0.998, Q2 = 0.95 in negative ionization modes). In total, 93 metabolites were structurally identified, wherein 21 low abundant metabolites showed distinct changes in abundance that were closely correlated with tea grade variation. These findings suggested their potential as markers to discriminate different grades of Bai Mudan white tea.
迄今为止，不同等级白茶的化学质量在很大程度上仍未得到探索。本研究的目的是建立一种不同等级白牡丹白茶质量评价的模型。我们应用非靶向超高效液相色谱-四极杆飞行时间质谱结合多元分析，分析了四个不同等级的白牡丹白茶。结果发现，特级和一级的代谢产物组成与二级或三级白茶相比具有更高的相似性，偏最小二乘判别分析模型显示出对样品变化的高解释能力（负离子模式下 R2Y=0.998，Q2=0.95）。总共鉴定出 93 种代谢产物，其中 21 种低丰度代谢产物的丰度变化明显，与茶等级变化密切相关。这些发现表明它们有可能作为区分不同等级白牡丹白茶的标志物。
