普洱茶茶氨酸的含量测定及其抗氧化活性的研究

The Research of the Content of L-Theanine in Pu-erh Tea and its Antioxidant Activity

目的研究普洱茶中茶氨酸的含量及其抗氧化活性。方法采用高效液相色谱方法对普洱茶中茶氨酸含量进行测定,分析条件为：Aglient TC-C18（4.6 mm×250 mm,5μm）;流动相：（A）0.1%磷酸水溶液（B）甲醇;流速：1.000 0 m L/min;进样体积：10μL;柱温：25℃;检测波长：203 nm。对分析条件进行优化和验证,构建了茶氨酸含量精确分析方法,进而通过清除1,1-二苯基-2-苦基肼基自由基（DPPH）法来测定其抗氧化活性。结果：30个普洱茶氨酸含量范围为7.350 1~14.235 3 mg/g,平均值为9.638 3 mg/g,抗氧化性在29.06%~72.28%之间。结论高效液相色谱法能够准确测定普洱茶中茶氨酸含量,对普洱茶抗氧化活性研究有利于对普洱茶保健疗效的进一步鉴定和提高。

Objective To study the contents of L-Theanine in Pu-erh teas and its antioxidant activity. Methods The content of L-Theanine was determined by HPLC which performed on an Agligent TC-C18（4.6 mm ×250 mm,5 μm） with a mobile phase of 0.1% phosphoric and methanol at a flow rate of 1.0 m L/min, a column temprature of 25℃, and a detection wavelength of 203 nm, and weighing the antioxidant activity of the Pu-erh tea by 1,1-diphenyl-2-picryhydrazyl（DPPH）. Results The content of L-Theanine in 30 batces of Pu-erh tea was 7.350 1-14.235 3 mg/g, and the average value was 9.638 3 mg/g.The antioxidant activity was between 29.06%-72.28%. Conclusion The content of L-Theanine was determined accurately by HPLC. The antioxidant activity of Pu-erh tea will promote the dentify and enhance of its health care effect.