3类茶中水溶性多糖及蛋白质的含量分析

目的]比较分析绿茶中的西湖龙井和碧螺春、红茶中的祈门红茶和立顿红茶以及普洱茶的云南特级地方标准样和临沧普洱茶的水溶性多糖和蛋白质含量。方法]茶叶样品经沸水浸提和透析等前处理,采用蒽酮-硫酸法和硫酸-咔唑法分别测定茶叶多糖的中性糖和酸性糖含量,用Bradford法分析蛋白质含量。结果]绿茶的总多糖平均值接近39.58 mg/g,红茶为30.73 mg/g,普洱茶为60.12mg/g,约是红茶的2倍。普洱茶的水溶性蛋白质含量约为18.57 mg/g,高于绿茶和红茶。结论]3类茶中,均以普洱茶的水溶性多糖及蛋白质含量最高。

Analysis of Water-soluble Polysaccharides and Protein Contents of Green Tea, Black Tea and Puer Tea

Objective] The water-soluble polysaccharides and protein contents of teas were compared to estimate the intake of drinking teas.These teas included green tea(Xihu Longjing and Biluo Chun),black tea(Qimen and Lipton) and Puer tea(Yunnan super standard sample and Puer sample produced from Lincang).Method] After boiling water extraction and dialysis of these teas,the contents of protein,neutral and acidic saccharide were investigated respectively by Bradford,anthrone-sulfuric acid and sulfuric acid-carbazole colorimetry method.Result] The average content of total polysaccharides of green tea were about 39.58 mg/g,as well as 30.73 mg/g in black tea which was half in puer tea.Protein contents of puer tea were nearly 18.57 mg/g,higher than anther two.Conclusion] Among these three kinds of tea,the contents of both polysaccharides and protein of Puer tea were the highest.