Extraction of purine alkaloids from mate (Ilex paraguariensis) using supercritical CO2

Experimental data for the supercritical CO2 extraction of purine alkaloids (caffeine, theobromine, and theophylline) from ground herbal mate tea (Ilex paraguaryensis) using a high-pressure apparatus are presented. Caffeine, theophylline, and theobromine were identified in the extracted fractions using HPLC. Results indicated a much higher CO2 selectivity for caffeine in comparison with those for theophylline and theobromine. Solubilities of pure compounds in carbon dioxide were also determined at 313.2, 323.2, 338.2, and 343.2 K, and pressures ranging from 14 to 24 MPa. Caffeine solubility exhibited a retrograde behavior with temperature while theophylline and theobromine manifested a normal behavior at conditions explored in this study. Solubilities in binary CO2/purine alkaloid model systems were much higher than those obtained during extraction of mate tea, demonstrating the difficulty of using binary data in predicting complex multicomponent behavior.