Elemental and Radiological Characterisation of Arbutus unedo L. Leaves and Tea: Impact of Preparation Method on Nutritional Risk/Benefit.

The aim of this study was to characterise the elemental and radiological composition of strawberry tree (Arbutus unedo L.) leaves and tea preparations and compare it with commercial Uvin H herbal mixture, widely used in treatment of urinary tract infections. The concentration of 17 elements and the activity concentration of selected radionuclides were measured in strawberry tree leaves/Uvin H herbal mixture, as well as in herbal tea prepared by infusion or decoction of leaves for 5 or 10 min. In both leaves and tea preparations, Ca, K, Mg, and Na were the most abundant elements, while the lowest levels were measured for As, Co, Mo, and Se. Only Cs and K were detected in analysed leaves/herbal mixture, while the activity of radionuclides in tea preparations was below the detection limit. The maximum possible health benefits can be obtained by a 10-min decoction of leaves, which resulted in the highest total phenolic content and antioxidant activity and levels of K, Ca, Mg, Na, Fe, Mn, and Se in comparison to the other preparation methods evaluated in this study. The calculated intake of potentially toxic elements and radionuclides does not represent a health risk to consumers.