气质联用在不同茶叶品质鉴定中的应用

【作者】 李万春；

【导师】 王瑛； 周申范； 许国旺；

【作者基本信息】 南京理工大学 ， 化学工程， 2012， 硕士

【摘要】 茶树为多年生常绿叶用作物,茶叶是茶树鲜叶经过工艺处理后制作而成。乌龙茶学名青茶,为我国六大茶类之一,主产于我国的福建、台湾和广东等省。乌龙茶属于半发酵茶,同一茶树品种因地域不同其品质也不一样,其中铁观音品种中在福建安溪县范围内的品质最佳。本论文基于气相色谱质谱联用(GC-MS)的非靶标代谢轮廓分析方法,开展安溪铁观音代谢组学研究,旨在从代谢组学的角度研究安溪县铁观音的品质与真伪。建立了用于茶叶研究的衍生化GC-MS的方法,对预处理条件进行了全面考察和优化,确定了样品预处理方法,用70%的甲醇水溶液作为最佳提取溶剂。同时对方法进行了表征(标准曲线、精密度实验、回收率等),该方法满足分析的需要。采用该方法对茶叶进行了分析,共鉴定了茶叶中69种代谢物,包括7种糖,14种氨基酸,20种有机酸。采用本论文建立的衍生化GC/MS方法,对安溪县境内8个乡镇种植的铁观音及其安溪县种植的三个乌龙茶品种(黄金桂、本山和毛蟹)进行代谢组学分析研究,PCA结果表明安溪县境内不同乡镇的铁观音表型有明显的差异,但相邻乡镇的茶叶代谢表型相似,为辨别安溪铁观音真伪奠定了基础,在国内尚未见过报道。用衍生化GC/MS方法还对绿茶、白茶、乌龙茶(铁观音和水仙)和红茶进行代谢组学研究,用主成分分析对数据进行处理,PCA结果表明不同发酵程度的四种茶叶代谢表型差异显著,同为乌龙茶的铁观音和水仙在PCA得分图上距离较近但也能清楚分类,发酵茶红茶与其它品种茶叶的差异最大。更多还原

【Abstract】 Tea tree is an evergreen shrub whose leaves are used to produce tea through processing. Tea quality varied widely according to type of tea and geographical origin et al. Semi-oxidised oolong tea is called blue-green tea, which is one of the six main types of Chinese teas. Major Oolong tea growing regions are Fujian, Taiwan, and Guangdong provinces. Anxi Tieguanyin is one of the best brands of the Oolong teas. In this thesis, Anxi Tieguanyin teas were investigate based on GC-MS non-targeted profiling method. The main results were as follows:A GC-MS metabolomics method for tea analysis was established. Sample pretreatment method was developed. Extraction solvent and derivatization conditions were investigated and optimized. The optimal extraction solvent was 70% methanol solution. Validation of the method was carried out. Repeatability, recovery and linearity results showed that the developed method could meet the analytical requirement. Using the developed method, a typical Tieguanyin was analyzed. A total of 69 metabolites were tentatively identified, including 7 sugars,14 amino acids,20 organic acids.Then, Tieguanyin and three main Oolong tea varieties (Benshan, Mao Xie and Huang Jin Gui) originated from eight towns within Anxi country were analyzed using the developed method. The PCA score plot showed that the phenotype of Oolong tea from different towns varied widely. Tieguanyin from geographically adjacent regions were clustered.Finally, four main types of tea including green tea, white tea, Oolong tea (Tieguanyin and Shui Xian) and the black tea were investigated. The PCA score plot indicated obvious discrimination of teas according to their degrees of fermentation. Tieguanyin and Shui Xian belong to the Oolong tea, and they are clustered nearby on PCA score plot. The phenotype of black tea have the biggest difference from other types of tea.更多还原