湖南红茶特征滋味化学成分研究

为全面了解湖南红茶特征滋味化学成分,本研究选取了湖南红茶代表性样品和典型外省样品,采用电子舌及高效液相色谱法等技术对红茶样品滋味进行评定及化学成分检测,并通过主成分分析（PCA）、正交偏最小二乘判别分析（OPLS-DA）可视化模式识别方法比较了不同嫩度等级和不同滋味类型湖南红茶化学成分的特征差异。结果表明：（1）糖组分总量、葡萄糖、麦芽糖、茶多酚、茶褐素、氨基酸组分总量、鲜味氨基酸、茶氨酸、茶黄素等含量可作为区分湖南红茶和外省红茶的主要滋味成分,其中糖组分总量、葡萄糖、麦芽糖、茶黄素等含量湖南红茶显著高于外省红茶。（2）一级湖南红茶茶汤中滋味化合物含量普遍较低,除氨基酸、茶褐素外,其他主要滋味成分均显著低于二级茶样;二级湖南红茶茶汤中滋味化合物在水浸出物、茶多酚、咖啡碱、氨基酸、茶黄素、茶红素等含量上表现突出;三级湖南红茶以儿茶素组分总量、糖类化合物、茶黄素、茶红素等成分含量相对较高,以茶多酚、氨基酸、茶褐素等成分含量相对较低。（3）“甘鲜味”茶汤中咖啡碱、儿茶素组分总量、非酯型儿茶素、EGC、茶黄素显著低于“略苦（浓）”茶汤。该研究结果可为湖南红茶产品的分类鉴别和滋味品质评价提供参考。

Study on the Chemical Constituents of Hunan Black Tea

In order to understand the characteristic taste chemicals of Hunan black tea, representative samples of Hunan black tea and typical samples from other provinces were selected. The taste and chemical constituents of black tea samples were evaluated by electronic tongue and high performance liquid chromatography. Visual pattern recognition method such as Principal component analysis (PCA) and partial least squares discriminant analysis (OPLS-DA) were used to compare the characteristic chemical compositions of Hunan black tea in different tenderness grades and flavor types. The results show that: (1) The contents of water extraction, glucose, maltose, tea polyphenols, theabrownin, amino acid, delicious amino acid, theanine and theaflavins could be used as the main flavor components to distinguish Hunan black tea from other black tea as water extraction, glucose, maltose and theaflavins in Hunan black tea are significantly higher. (2) Most of the contents of taste components in the first grade of Hunan black tea soup were lower than those in other grades. Except for amino acids and thearubigins, other main flavor components were significantly lower than those of second grade tea. The contents of water extracts, tea polyphenols, caffeine, amino acids, theaflavins, thearubin were rich in the second grade tea soup. The contents of catechins, carbohydrates, theaflavins, thearubin and other compounds in the third grade tea was relatively high, while the contents of tea polyphenols, amino acids, thearubin and other compounds were relatively low. (3) The contents of caffeine, catechins, non-ester catechins, EGC and theaflavins in the “sweet and delicious” tea soup were significantly lower than those in the “slightly bitter (strong)” tea soup. The research results provided a reference for the classification and identification of Hunan black tea products and the evaluation of taste quality.