都匀毛尖绿茶与红茶中氨基酸含量的测定

Determination of amino acids content in duyun maojian green tea and black tea

采用茚三酮比色法,以茶氨酸为标准品,在最大吸收波长570 nm处测定都匀毛尖绿茶与红茶中游离氨基酸的含量。通过研究浸提时间、茶叶用量、浸提溶剂等几个工艺参数,得到最优提取条件。比较红茶与绿茶中游离氨基酸提取效果,发现红茶用70%乙醇提取,提取为时间30min,绿茶用80%乙醇提取,提取时间为30min,氨基酸提取效果最佳,且都匀毛尖红茶中氨基酸的含量比绿茶中高出近2倍。

Using theanine as the standard substance,the content of free amino acids in duyun maojian green tea and black tea was determined via ninhydrin colorimetry at the maximum absorption wavelength of 570 nm.The optimum extraction conditions were obtained by systematically studying several process parameters such as extraction time,tea dosage,extraction solvent,etc.By comparing the content of free amino acids in black tea and green tea,the results showed that the best extraction efficiency for the black tea was obtained when the extraction time was 70%ethanol and the extraction time was 30 minutes.For the green tea,the extraction time was 80%ethanol and the extraction time was 30 minutes.Moreover,the amino acid content of duyun maojian black tea is two times higher than that of green tea.