RESUMO
In this investigation, liquid carbon dioxide at 20 degrees C and 150 bar was used for the selective extraction of caffeine and theobromine from dry leaves of mate. A comparison between the chromatograms from CO2 extraction and traditional solvent extraction supports the selectivity of carbon dioxide for these purine alkaloids. The advantages of selective liquid CO2 extraction in terms of speed and resolution of UV/HPLC is also evidenced. A randomized block design of experiments was proposed to investigate the influence of 16 progenies of Ilex paraguariensis grown in 3 diverse sites on the contents of caffeine and theobromine in liquors of mate leaves obtained by extraction with compressed CO2. A significant effect of both these factors on the parameters investigated was observed by involving the F distribution in the statistical analysis. A cluster analysis based on the experimental uncertainties in the contents of these two methylxanthines has identified from four to six different groups of mate progenies.