人工采摘和管理对普洱生茶化学成分的影响分析

Influence of Manual Picking and Management on Chemical Composition of Raw Pu-erh Tea

以荒废茶园在恢复人工采摘和管理后采摘的大叶种茶青鲜叶制成的晒青毛茶(普洱生茶)为研究样本,使用基于高分辨质谱的代谢组学技术对普洱茶内含物质进行分析,发现采摘及人工管理会显著提高呈味鲜爽的茶氨酸和谷氨酸含量以及茶叶总氨基酸含量,还能提高普洱茶中增强鲜味的生物碱类物质和回甘的儿茶素类物质含量,从而改善普洱茶的口感和品质。化学分析显示,茶叶的总多酚和在细胞外抗氧化能力在人工管理后无显著变化,而细胞增殖和抗氧化性实验表明,人工管理普洱茶对肿瘤细胞扩增的抑制能力和在细胞内的抗氧化能力显著增强。人工采摘和管理对茶叶的无机离子、总多酚和咖啡因含量影响较小,表明人工管理和采摘过程没有对植物的生理状态造成较大影响。本研究揭示了普洱茶树从荒废到人工管理转变过程中普洱茶内含物质的变化规律,为研究普洱茶品质变化规律提供理论支撑。

In this study,mass spectrometry-based metabolomics was used to analyze the chemical composition of raw Puerh tea made from the fresh leaves of the large-leafed tea cultivar picked from an abandoned tea plantation where manual picking and management have been resumed.It was found that manual picking and management resulted in a significant increase in the contents of theanine,glutamic acid,both responsible for the fresh and brisk taste,and total amino acids,and also increased the contents of umami-enhancing alkaloids and catechins responsible for the sweet aftertaste of Pu-erh tea,thereby improving the taste and quality of the tea.Chemical analysis showed that manual management did not significantly change the total polyphenol content or antioxidant capacity outside cells of the tea.However,cytotoxicity and antioxidant activity tests showed that the inhibitory effect on the proliferation of cancer cells(U2OS) and the antioxidant capacity inside cells were enhanced by manual management.Manual picking and management had little effect on the contents of inorganic ions,total phenols or caffeine of the tea,indicating manual intervention had no significant influence on the physiological status of the plants.This study may provide a theoretical basis for the study of the quality of raw Pu-erh tea.