Chemical and thermal evaluation of grass mate (ilex Paraguariensis St. Hil.) native progenies, from Kaiowá and Guarani indigenous communities/ms

This study aimed thermal evaluation (TG/DTG and DSC), mineral elements quantification by atomic absorption and caffeine content of native progenies of grass mate (Ilex paraguariensis St.), in order to complement the genetic evaluation of these progenies at field to allow the selection of more productive ones for sustainable exploitation of natural resources by the indigenous community. The thermogravimetric analysis (TG/DTG) corresponds to the mass thermal decomposition process, which began at 150°C and had a sharp peak in exothermic reaction of 450°C at the end of the process. The curves (DSC) have similar thermal behavior in the process of thermal decomposition that varies in temperature range of 150°C to 450°C. All progenies have an initial mass loss of around 10%, due to the water removal and other volatile compounds. The analysis of minerals performed by the atomic absorption spectrophotometry did not show significant differences between the examined elements (Na, Mn, Zn, Cu, Ca, Fe, Mg, and K), however the progeny number 7 presented significative mean values of potassium (± 2681.23), and it is observed, also, similarity between the blocks. The concentration of caffeine content varied in the range of 6.566 mg/g to 13.630 mg/g, with emphasis on blocks 1 and 4, there was no significant deviation among treatments and calculated R value was 0.9945 between 0.002 to 0.007 mg/g, which increases the energetic potential of plant material. So, grass mate represents an alternative of employment and income to the indigenous community.