采用光学方法针对四种茶叶及其四种主要组份在800～3800 cm-1中红外“指纹”特征区域的光谱进行系统研究,采集了不同产地的碧螺春和铁观音以及决定茶叶品质的主要成份中咖啡因、谷氨酸和表儿茶素和花青素类物质的中红外光谱。通过建立模型对各特征光谱进行主成份拟合分析了茶叶品种、产地差异与各主要成份含量的关系。结果表明,不同茶叶之间的差异可表现在其主成份相对含量上:对于不同种类茶叶的碧螺春和铁观音,差异主要表现在茶叶有效成份的含量不同,前者中的各组份含量相对较低;对于不同产地的同种茶叶,差异主要表现在咖啡因和表儿茶素的相对含量不同,其中原产地茶叶中含量相对较高。此研究为利用光学方法对茶叶的种类和品质实现快速检测提供重要参考。

It is important for tea trade of China to improve a method of rapid tea identification. Infrared spectroscopy is used to study the tea based on their “finger character” in the spectral region of 800～3800 cm-1. Four kind of brand tea in China and its principal components have been studied, including Biluochun tea and Tieguanyin tea from different areas, caffcine, epicatechin, glutamic acid and anthocyanic. Contents of components in different kind of tea have been obtained by principal component model analysis from their middle infrared spectroscopy. The results show that the difference among these tea are revealed from the relative content of principal components. The distinguish between Biluochun tea and Tieguanyin tea exhibit the content of effective component, which the former has lower content. Meanwhile, the distinguish among the same kind of tea from different producing area mainly exhibit relative content of epicatechin and caffcine, which tea from original area has relatively higher content. These conclusion has verified the possibility of tea identification by spectral method and has great help for rapid tea identification.