青砖茶和红巧梅花茶中铜和锰溶出特性研究

Study on Dissolution Characteristics of Copper and Manganese in Brick Tea and Scented Tea

以青砖茶和红巧梅花茶为研究材料,建立了微波消解-原子吸收光谱法测定铜和锰的检测方法,分析两种茶叶中铜、锰元素含量及熬制的青砖茶和泡制的红巧梅花茶中铜、锰元素溶出率动态变化,指导消费者正确、健康饮茶。结果表明,方法回收率、标准曲线线性范围和线性关系均符合方法学要求。青砖茶和红巧梅花茶中Cu元素含量接近,分别为56.32 mg/kg和66.35 mg/kg;青砖茶中Mn元素含量比红巧梅花茶丰富,分别为1 464.02 mg/kg和45.11 mg/kg。Cu元素在熬制的青砖茶中溶出率为70.65%~88.31%,最高溶出率出现在放置后30 min;泡制的红巧梅花茶中的Cu元素溶出率稍低,在65.01%~80.23%之间,15 min时的溶出率最高,基本呈下降趋势。Mn元素在青砖茶中溶出率为5.99%~9.56%,呈逐渐上升趋势;红巧梅花茶中26.11%~28.57%之间,呈下降趋势。

Analytical method of determination of Cu and Mn in brick tea and scented tea by atomic absorption spectrometry were developed using microwave digestion. Then, Cu and Mn contents and the dynamic changes of the dissolution rate were investigated after different pre-aeatment and different time. The results showed that recovery rate, standard curve linear range and correlation coefficient were in accordance with the requirements of the methodology. The contents of the Cu in brick tea and scented tea were determined to be 56.32 mg/kg and 66.35 mg/kg; the contents of the Mn were 1 464.02 mg/kg and 45.11 mg/kg, respectively. Dissolution rate of the Cu in brick tea that boiled 5 min was 70.65%-88.31%, and was no significant change alter 30 min. Dissolution rate of Cu in scented tea in boiling water was 65.01%-80.23%, highest dissolution rate was 80.23% at 15 min. Dissolution rates of Mn in boiled brick tea and scented tea infusion were 5.99%-9.56% and 26.11%- 28.57%.