The study of the influence of industrial processing on the elemental composition of mate tealeaves (Ilex paraguariensis) using the PIXE technique

The influence of the industrial processing on the elemental composition of mate tealeaves was investigated using the Particle Induced X-ray Emission (PIXE) technique. Considerable changes were observed after the main steps of the industrial process. The concentration of Mg, P, S, K and Ca increased after the roasting (rapid contact of the leaves with wood flames and fog) and the drying processes, possibly due to the presence of contaminants in the hot gases (originated from burning wood) used in both steps, biomass burning and evaporation of water. Elements like Al, Si, Mn, and Rb increase in concentration after the roasting but decrease after the drying process, while Fe and Ti were not affected by the drying step. Differences in concentration for several elements were observed due to the stationing period (waiting between the drying and the packaging of the leaf material). The mineral contents of leaves and twigs were also compared and results show that most of the elements are present in greater amounts in the leaves, except for Ca, Ti and Zn. These results highlight the importance of understanding the influence of the industrial process on the mineral content of mate tealeaves for the development of new products with controlled characteristics. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.