酸茶营养成分及微量元素分析

按照茶叶等食品的国家标准方法,测定了包括水浸出物、茶多酚、游离氨基酸等在内的7种酸茶常量成分;湿法消化酸茶样品,采用火焰原子吸收分光光度法测定了Fe、Zn、Cr、Cu、Mn和Ni 6种微量元素的含量。结果显示:酸茶中水分、水浸出物、茶多酚、游离氨基酸、可溶性总糖、叶绿素和总黄酮的含量分别为7.16%、49.13%、26.29%、0.88%、19.90%、0.054%和6.56%;酸茶中微量元素的含量Mn﹥Cu﹥Cr﹥Fe﹥Zn,Ni元素未检出。各元素的加标回收率为98.70%～101.80%,相对标准偏差为0.04%～2.35%,准确度和精密度均符合要求。酸茶中茶多酚、可溶性总糖含量较高;火焰原子吸收分光光度法测定酸茶中的金属元素含量是可行的。

Analysis on the Nutrient Components and Trace Elements of Acid Tea

Providing reference for the component analysis and development of acid tea.the contents of water extract,polyphenols and free amino acid were determined according to the national standard method of food.Seven trace elements,such as Fe,Zn,Cr,Cu,Mn and Ni,were determined by flame atomic absorption spectrometry(FAAS) after wet digesting.The contents of moisture,water extracts,polyphenols,free amino acid,soluble sugar,chlorophyll and total flavonoids in acid tea were determined as 7.16%,49.13%,26.29%,0.88%,19.90%,0.054% and 6.56% respectively.The sequence of trace element content in acid tea was Mn,Cu,Cr,Fe,Zn from high to low.However,Ni was not found.The recovery rate of various experimental elements was 98.70%~101.80%,RSD is 0.04%~2.35%,with the accuracy and precision according to the requirements.Polyphenols and soluble sugar were higher;FAAS can be used in determination of metal element contents in acid tea.