不同类型白茶儿茶素、香气成分与感官品质比较

白茶是我国特有的一种微发酵茶，为探明不同类型白茶的品质差异，本研究选取了白毫银针、白牡丹、贡眉、寿眉、新工艺白茶共10个白茶样品，分别进行了高效液相色谱(HPLC)检测儿茶素、气相色谱-质谱(GC-MS)检测香气成分以及感官评价，并结合方差分析和OPLS-DA等多元统计学分析。结果表明，不同类型白茶中儿茶素含量差异较大，贡眉的总儿茶素含量最高，寿眉最低，分别为66.84和32.66 mg/g，并且所有白茶共检测到50种香气物质，主要香气组分有正己醛、(E)-2-己烯醛、苯甲醛、芳樟醇及其氧化物(I、II)等。白毫银针、白牡丹、贡眉、寿眉等4种传统工艺白茶的香气组成和含量与新工艺白茶有明显差异，其中，(E)-2-戊烯醛、2-庚酮等8种香气成分在4种传统工艺白茶中大量存在，而在新工艺白茶中未检测出。通过多组分化学计量学分析发现，白毫银针、白牡丹、贡眉与新工艺白茶的儿茶素和香气代谢物存在显著差异，而寿眉与新工艺白茶相差不大。本研究初步探明了不同类型白茶的品质差异，为白茶风味品质调控提供理论依据。

Comparison of Catechins,Aroma Components and Sensory Quality of Different Types of White Tea

White tea is a unique kind of micro-fermented tea in China.In order to explore the quality differences of different types of white tea,ten samples including Baihaoyinzhen,Baimudan,Gongmei,Shoumei and New White tea were selected for high performance liquid chromatography(HPLC) detection of catechins,gas chromatography-mass spectrometry(GCMS) detection of aroma components and sensory evaluation,combining with multivariate statistical analysis such as analysis of variance and OPLS-DA.The results showed that the content of catechins in different types of white tea varied greatly,the total catechin content of Gongmei was the highest and that of Shoumei was the lowest,which were 66.84 and32.66 mg/g respectively,and a total of fifty aroma substances were detected in all white tea,the main aroma components consisted of hexanal,(E)-2-hexenal,benzaldehyde,linalool and its oxides(I,II).The aroma composition and content of Baihaoyinzhen,Baimudan,Gongmei and Shoumei were different from those of the New White tea.Among them,eight aroma components such as(E)-2-pentenoaldehyde and 2-heptanone existed in a large number in the four traditional white tea,but they were not detected in the New White tea.Through multi-component chemometric analysis,it was found that there were significant differences in catechins and aroma metabolites between Baihaoyinzhen,Baimudan,Gongmei and New White tea,but there was little difference between Shoumei and New White tea.This study preliminarily proved the quality differences of different types of white tea,which provided a theoretical basis for the regulation of white tea flavor quality.