Pasquini Benedetta, Orlandini Serena, Goodarzi Mohammad, Caprini Claudia, Gotti Roberto, Furlanetto Sandra
Department of Chemistry "U. Schiff", University of Florence, Via U. Schiff 6, 50019 Sesto Fiorentino, Florence, Italy.
Department of Biosystems, MeBioS Division, KU Leuven, Kasteelpark Arenberg 30 Box 2456, 3001 Leuven, Belgium.
Talanta. 2016 Apr 1;150:7-13. doi: 10.1016/j.talanta.2015.12.003. Epub 2015 Dec 4.
Catechins and methylxanthines were determined in 92 green tea (GT) samples originating from Japan and China by using micellar electrokinetic chromatography with the addition of (2-hydroxypropyl)-β-cyclodextrin. GT samples showed high concentrations of (-)-epigallocatechin gallate and caffeine, with (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epicatechin in relevant content and (+)-catechin, (-)-catechin and theobromine in much lower amounts. The amount of all the considered compounds was higher for Chinese GTs, with the exception of (-)-epicatechin gallate. Pattern recognition methods were applied to discriminate GTs according to geographical origin, which is an important factor to determine quality and reputation of a commercial tea product. Data analysis was performed by principal component analysis and hierarchical cluster analysis as exploratory techniques. Linear discriminant analysis and quadratic discriminant analysis were utilized as discrimination techniques, obtaining a very good rate of correct classification and prediction.
通过加入（2-羟丙基）-β-环糊精的胶束电动色谱法，对92份来自日本和中国的绿茶（GT）样品中的儿茶素和甲基黄嘌呤进行了测定。GT样品中（-）-表没食子儿茶素没食子酸酯和咖啡因浓度较高，（-）-表没食子儿茶素、（-）-表儿茶素没食子酸酯和（-）-表儿茶素含量相关，而（+）-儿茶素、（-）-儿茶素和可可碱含量低得多。除（-）-表儿茶素没食子酸酯外，所有被研究化合物的含量在中国GT中更高。模式识别方法被用于根据地理来源区分GT，地理来源是决定商业茶产品质量和声誉的一个重要因素。采用主成分分析和层次聚类分析作为探索性技术进行数据分析。利用线性判别分析和二次判别分析作为判别技术，获得了非常高的正确分类和预测率。
