茶膏的营养成分分析

为了解市售茶膏的营养成分组成及含量,分析测定了5个不同茶膏的茶多酚、水浸出物、游离氨基酸总量、咖啡碱、水分、灰分、水解氨基酸、矿质元素及重金属含量。结果表明,茶膏中游离氨基酸总量、咖啡碱、茶多酚、水浸出物含量较高,由绿茶原料制得的茶膏中茶多酚含量远高于红茶茶膏;含有17种水解氨基酸,谷氨酸含量最高,天门冬氨酸次之;含有钾、钙、钠、镁、锌等9种矿质元素,常量元素具有高钾低钠的典型特征,铁、锌、锰等微量元素含量也较为丰富;重金属铅、镉、砷、汞含量均低于限量标准;不同类型的茶膏品质差异较大。

Analysis of Nutritional Components in Different Tea Creams

The main biochemical components and mineral elements were determined to study on composition and contents of nutritional components of tea creams. The results showed that the samples were in rich of free amino acids, caffeine, water extracts and tea polyphonies. The contents of tea polyphonies in green tea creams were higher than that in red tea creams. The hydrolyzed samples contained 7 kinds of amino acids, in which the content of glutamic acid was highest followed by aspartic acid. The samples were in rich of mineral elements, in which the content of K was higher than Na. The content of harmful metals complied with Limitation Standard of Contaminants in tea. The contents of biochemical components and mineral elements of tea creams were quite different.