茶叶中有机酸及其浸出特性研究

Study on Organic Acids Contents in Tea Leaves and its Extracting Characteristics

研究了不同叶位、不同品种和不同茶类茶叶中有机酸的含量,以及不同冲泡时间、冲泡温度和pH条件下有机酸的浸出特性。结果表明:有机酸中奎尼酸、苹果酸、柠檬酸和草酸的含量要高于酒石酸和L-抗坏血酸的含量,有机酸总量随着鲜叶嫩度的下降而减少,其中草酸的含量下降明显,第4叶的含量仅为一芽一叶的49.5℅;不同茶叶品种对有机酸含量有较大影响,福鼎种的含量最低,黄金桂的含量最高;不同茶类间茶叶有机酸含量变化显著,依次为:红茶>乌龙茶>绿茶>普洱茶;另外有机酸的浸出随着冲泡温度的提高和冲泡时间的延长而增加,但随着pH值的提高却呈减少趋势。

The effects of different leaf position, different tea cultivars, different tea kinds on the content and extracting characteristics of organic acids in tea under different brewing time, brewing temperature and pH were systematic analyzed. The results showed that quinic acid, malic acid, citric acid and oxalic acid content in organic acids were higher than tartaric acid and L-ascorbic acid. With the declining of tea tenderness, the content of total organic acids decreased, including oxalic acid content decreased significantly, the content of the fourth leaf was 49.5%of that in one bud a leaf. The different tea cultivars had great effect on the organic acids content. The lowest organic acids content was Fuding cultivar and the highest was Huangjingui cultivar. The organic acid content in different kinds of tea changes significantly, with descending order of black tea〉Oolong tea〉green tea〉pu-erh tea. With the increasing of brewing temperature and time, the extracting content of organic acids increased. But there was a decreasing tendency in the extracting content of organic acids with the increasing of the pH value.