The United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu City 501-1193, Japan.
The United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu City 501-1193, Japan; Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu City 501-1193, Japan.
Food Res Int. 2022 Oct;160:111731. doi: 10.1016/j.foodres.2022.111731. Epub 2022 Jul 21.
During the processing of black tea, enzymatic oxidation converts tea catechins into a complex mixture of oxidative products, including theaflavins, and thearubigins. In this study, ultra-performance liquid chromatography was carried out to analyze the tea extracts collected after each processing stage to clarify the quantitative changes in these compounds during black tea processing. It was found that the catechin content was significantly reduced during processing, and in particular between the later rolling and fermentation periods. In contrast, the variation in the theaflavin content was negatively correlated with the catechin content. Twenty-three compounds containing the known catechins dimers and flavonol glycosides were identified by liquid chromatography-mass spectrometry (LC-MS). In addition, 45 components whose contents increased significantly between the late rolling and late fermentation stages were extracted using principal components analysis by LC-MS. It was considered that due to the catechin-like units present in these components, they likely contribute to thearubigin production during black tea processing.
在红茶加工过程中，酶促氧化将儿茶素转化为复杂的氧化产物混合物，包括茶黄素和茶红素。在这项研究中，采用超高效液相色谱法分析了每个加工阶段收集的茶提取物，以阐明儿茶素类化合物在红茶加工过程中的定量变化。结果表明，儿茶素含量在加工过程中显著降低，特别是在后期揉捻和发酵期间。相比之下，茶黄素含量的变化与儿茶素含量呈负相关。通过液相色谱-质谱联用（LC-MS）鉴定出 23 种含有已知儿茶素二聚体和黄酮醇糖苷的化合物。此外，通过 LC-MS 的主成分分析提取了在后期揉捻和后期发酵阶段之间含量显著增加的 45 种成分。由于这些成分中存在儿茶素样单元，因此它们可能有助于红茶加工过程中茶红素的生成。
