基于代谢组学研究不同花色种类云南白茶的化学成分差异

以云白毫、白牡丹（包括月光白一级和月光白二级）、云寿为云南白茶的代表性样品，采用基于超高效液相色谱-四极杆轨道阱质谱的代谢组学方法对不同花色种类云南白茶的化学成分差异进行研究。共鉴定出120 个化合物，包括儿茶素类、二聚儿茶素类、氨基酸类、生物碱类、酚酸类、有机酸类、香气糖苷类、N-乙基-2-吡咯烷酮取代的儿茶素类、黄酮糖苷类、脂质类等。偏最小二乘法判别分析和热图分析分别表明不同花色种类云南白茶的化学成分存在较大差异，共得到76 个化合物具有组间显著性差异（P＜0.05），其中儿茶素类、二聚儿茶素类、生物碱类、酚酸类、茶氨酸等化合物随云南白茶原料嫩度的降低，含量下降；部分氨基酸和杨梅素苷在白牡丹中含量相对较高；芹菜素苷、山柰酚苷、槲皮素苷、脂质类化合物在云寿中含量相对较高。本研究可为云南白茶感官品质和营养价值的研究以及等级判别提供理论依据。

Metabolomics Analysis of Difference in Chemical Components among Different Types of Yunnan White Tea

In this study, the difference in the chemical composition among the representative types of Yunnan white tea, Yun Baihao, Yueguangbai grade I and II of Baimudan and Yun Shou were investigated by metabolomics based on ultra-high performance liquid chromatography-quadrupole orbitrap mass spectrometry (UPLC-Q-Orbitrap-MS). A total of 120 compounds were identified, including catechins, dimeric catechins, amino acids, alkaloids, phenolic acids, organic acids, aroma glycosides, flavonoid glycosides, N-ethyl-2-pyrrolidinone-substituted flavan-3-ols, and lipids. Partial least squares-discriminant analysis (PLS-DA) and heatmap analysis showed that there were distinct differences in the chemical components among the different types of Yunnan white tea. A total of 76 significantly differential compounds were among these types (P < 0.05). The contents of catechins, dimeric catechins, alkaloids, phenolic acids, and theanine were higher in white tea from younger tea leaves; some amino acids and myricetin glycosides were richer in Baimudan, while the contents of apigenin glycoside, kaempferol glycoside, quercetin glycoside and lipid compounds were relatively high in Yunshou. This study can provide a theoretical basis for the studies of sensory quality, nutritional value and grade discrimination of Yunnan white tea.