湖南红茶品质特征分析及其等级判别模型的构建

本研究对26个湖南省特级、一级和二级工夫红茶样品进行感官审评与理化分析，对茶多酚、游离氨基酸等重要品质成分进行单因素方差分析、主成分分析以及判别分析，并构建其等级典型判别函数模型。结果表明:在特级红茶中，关键品质成分茶多酚、游离氨基酸、咖啡碱、茶黄素含量最多，一级红茶次之，二级红茶最少。在不同等级的湖南红茶中，游离氨基酸、茶氨酸、表没食子儿茶素（EGC）含量无显著性差异，而表儿茶素（EC）、表没食子儿茶素没食子酸酯（EGCG）、茶黄素-3-没食子酸酯（TF-3G）、茶黄素-3’-没食子酸酯（TF-3'G）含量具有显著（P<0.05）性差异。建立的典型判别模型对不同等级湖南红茶的分类具有较好的准确性，其自身验证法的准确率达100%，交互验证法的准确率达84.62%。通过对湖南不同等级工夫红茶的品质化学特征的分析及典型判别模型的构建，本研究为湖南红茶的等级划分提供了一种合理的量化方法。

Analysis of the Quality Characteristics of Hunan Black Tea and the Establishment of Its Grade Discrimination Model

26 black tea samples from Hunan province were collected for sensory evaluation, quality analysis and the construction of a typical discriminant model. The results showed that premium black tea contained the most key quality ingredients, such as tea polyphenols, free amino acids, caffeine, and theaflavins, followed by first grade black tea and second grade black tea. There were no significant differences in the contents of free amino acids, theanine, and EGC in the different grades of Hunan black tea, but there were significant (P<0.05) differences in the contents of EC, EGCG, TF-3G, and TF-3'G between any two grades. The typical discriminant analysis had better accuracy for the classification of different grades of Hunan black tea. The accuracy rate of its own verification method was 100% while the interactive verification method had 84.62% accuracy. Through the analysis of the quality and chemical characteristics of different grades in Hunan Gongfu black tea and the construction of a typical discrimination model, the study would provide a reasonable quantitative method for the classification of Hunan black tea.