不同浸提方法茯砖茶多酚和咖啡碱的HPLC测定

目的]研究不同的提取方法对茯砖茶中的多酚类物质和咖啡碱含量的影响,为建立最佳的茯砖茶浸提方法提供参考。方法]采用高效液相色谱(HPLC)法测定了5种不同的提取方法对茯砖茶中的8种多酚,包括没食子酸(GA)、没食子儿茶素(GC)、表没食子儿茶素(EGC)、表没食子儿茶素没食子酸酯(EGCG)、没食子儿茶素没食子酸酯(GCG)、表儿茶素(EC)、表儿茶素没食子酸酯(ECG)及儿茶素没食子酸酯(CG)和咖啡碱(CAF)的含量的影响。结果]8种多酚类物质在0.000 6～0.300 0 mg/ml范围内具有良好的线性关系,且70%甲醇70℃水浴浸提法较蒸馏水100℃水浴和70℃水浴更能有效地提取茯砖茶的多酚组分;而咖啡碱的含量,蒸馏水超声提取法的测定值最高。结论]对于多酚总量,70%甲醇浸提法较优,而对于咖啡碱类较稳定的化合物,蒸馏水超声浸提更具有优势。

Determination of Polyphenols and Caffeine of Fuzhuan Tea Extracted with Different Methods by HPLC

Objective] To study the influence of extraction methods on the content of polyphenols and caffeine in Fuzhuan tea,and provide references for establishing the best extraction method.Method] The influence of five extraction methods on the contents of eight polyphenols,including gallic acid(GA),(-)-gallocatechin(GC),(-)-epigallocatechin(EGC),(-)-epigallocatechin gallate(EGCG),(-)-gallocatechin gallate(GCG),(-)-epicatechin(EC),(-)-epicatechin gallate(ECG) and(-)-catechin gallate(CG) and caffeine(CAF)in Fuzhuan tea was studied by high performance liquid chromatography(HPLC).Result] The eight phenolic compounds showed good linearity within the test range of 0.000 6-0.300 0 mg/ml,and the polyphenols extracted with 70% aqueous methanol in water bath at 70 ℃ was comparatively more effective than that with distilled water in water bath at 100 ℃,and the content of caffeine extracted by distilled water in ultrasonic bath was the highest.Conclusion] 70% methanol extraction was the best for the extraction of polyphenols and the distilled water ultrasonic extraction was much better for the extraction of caffeine.