Levels of essential and non-essential elements in black teas commercialized in Poland and their transfer to tea infusion

Twelve bagged black tea samples available in Poland were analyzed for P, K, Ca, Mg, Na, Fe, Mn, Zn, and Al concentrations both in leaves and their infusion. In dry tea the most abundant element among the macroelements was K followed by P, Mg and Ca, whereas the Al content was prominent among the trace metals tested, followed by Mn, Fe and Zn. Both macroelements and trace metals were extracted from the black tea leaves to tea infusion. The results showed that the percentage transfer differed significantly among all elements. The solubility of Ca and K was the highest among the elements studied and averaged 63.8% and 60.7%, respectively. The percentage transport of trace elements was also relatively high except for Fe, which was insoluble, and its content remained higher in the solid particles during beverage preparation.