南岳云雾茶的品质评价及其方法学研究

Determination of Active Ingredients in Nanyue Yunwu Tea and its Methodology

目的:建立茶叶中茶氨酸、5种儿茶素类(+C、EC、EGC、EGCG、ECG)、总黄酮和咖啡因含量测定的HPLC法,并对南岳云雾茶的品质进行评价。方法:茶叶中有效成分的提取参照GB/T 8303-2018,分析采用安捷伦Eclipse XDB-C18色谱柱(4.6 mm×250 mm,5μm),流动相为2%乙酸水(A)-2%乙酸乙腈(B),流速0.8 mL/min^(-1),柱温25℃,检测波长为203 nm、278 nm、360 nm。结果:方法学结果显示+C、EC、EGC、EGCG、ECG、咖啡因、L-茶氨酸及芦丁分别在50.00μg∙mL^(-1)~150.00μg∙mL^(-1),50.00μg∙mL^(-1)~150.00μg∙mL^(-1),50.00μg∙mL^(-1)~150.00μg∙mL^(-1),100.00μg∙mL^(-1)~250.00μg∙mL^(-1),100.00μg∙mL^(-1)~300.00μg∙mL^(-1),10.00μg∙mL^(-1)~100.00μg∙mL^(-1),100.00μg∙mL^(-1)~400.00μg∙mL^(-1)及10.00μg∙mL^(-1)~100.00μg∙mL^(-1)浓度范围内线性关系良好,加样回收率为92.49%-105.56%。在上述条件下,测得南岳云雾茶中茶氨酸、儿茶素类、总黄酮和咖啡因的含量分别为67.32 mg/g、260.42mg/g、3.712 mg/g和34.05 mg/g。结论:南岳云雾茶中茶氨酸、儿茶素类及总黄酮的含量相对较高。该方法简便、准确、快速、重现性好,可为茶叶的质量控制提供科学的依据。

Objective:A HPLC method for the determination of theanine,five catechins(+C,EC,EGC,EGCG,ECG),total flavonoids and caffeine in tea was established,and the quality of Nanyue Yunwu tea was evaluated.Methods:According to GB/T 8303-2018,the effective components in tea were extracted and deteminated by Agilent Eclipse XDB-C18 chromatographic column(4.6 mm×278 nm,5μm),mobile phase was 2%acetic acid water(A)-2%acetic acid acetonitrile(b),flow rate was 0.8 mL∙min^(-1),column temperature was 30℃,and detection wavelengths were 203 nm,278 nm,360 nm,respectively.Results:The results of methodology showed that+C,EC,EGC,EGCG,ECG,caffeine,L-theanine and rutin were 50.00μg∙mL^(-1)~150.00μg∙mL^(-1),50.00μg∙mL^(-1)~150.00μg∙mL^(-1),100.00μg∙mL^(-1)~200μg∙mL^(-1)respectively.The linear relationship is good in the concentration ranges of 10.00μg∙mL^(-1)~100.00μg·mL^(-1),100.00μg∙mL^(-1)~400.00μg∙mL^(-1)and 10.00μg∙mL^(-1)~100.00μg∙mL^(-1),and the recovery rate is 92.49%~105.56%.The results of methodology showed that the linear relationships of+C,EC,EGC,EGCG,ECG,caffeine,L-theanine and rutin were good in the concentration ranges of 50.00~150.00μg∙mL^(-1),50.00μg∙mL^(-1)~150.00μg∙mL^(-1),50.00~150.00μg∙mL^(-1),100.00μg∙mL^(-1)~250μg∙mL^(-1),100.00μg∙mL^(-1)~300.00μg∙mL^(-1),10.00μg∙mL^(-1)~100.00μg∙mL^(-1)and 100.00μg∙mL^(-1)~400.00μg∙mL^(-1),respectively.And the recovery rate ranged from 92.49%-105.56%.Under the above conditions,the contents of theanine,catechins,total flavonoids and caffeine in Nanyue Yunwu tea were 67.32 mg∙g^(-1),260.42 mg∙g^(-1),3.712 mg∙g^(-1) and 34.05 mg∙g^(-1),respectively.Conclusion:The contents of theanine,catechins and total flavonoids in Nanyue Yunwu tea are relatively high.The method is simple,accurate,rapid and reproducible,and can provide scientific basis for the quality control of tea.