Supercritical carbon dioxide extraction of caffeine from Yerba mate

COGOI, LAURA1, CASSEL, EDUARDO2, FERRARO, GRACIELA E. 1 Y FILIP, ROSANA

Montevideo, Uruguay

Simposio; Primer Simpósio Internacional sobre Yerba mate y Salud; 2008

Yerba Mate contains methylxanthines (caffeine and theobromine), flavonoids, caffeoylderivatives compounds, vitamins, and saponins.The pharmacological effects of caffeine, including stimulation of the central nervous system, have been extensively investigated. Consumption of caffeine containing products is contraindicated in the case of ulcers, severe cardiovascular diseases, insomnia and nervous tension. On the other hand, caffeine is widely used in the pharmaceutical and cosmeceutic industry. Phenylpropanoids are phenolic compounds usually recognized as responsible for the antioxidant and choleretic activities of plant extracts. Recent works support the role of them as protective agents against cardiovascular disease, breast, esophageal, gastrointestinal, lung and skin cancer. The use of Yerba Mate has gained popularity in the United States, Europe and Asia where it is sold for medicinal, cosmetic preparations or as an ingredient in functional foods. It was reported that Yerba Mate contributes to increase the antioxidant defense of the organism against free radicals attack. Some of these activities are ascribed to the significant amount of phenolic compounds found in Yerba Mate. In this work, a method for the extraction of caffeine from Yerba Mate using high pressure apparatus in a pilot scale was developed. The experimental apparatus includes a positive liquid displacement pump for solvent delivery, a 1000 mL high-pressure extraction vessel, and a separator flask. The Yerba Mate leaves, 0.200 Kg, were extracted with supercritical carbon dioxide at 170 bar, and 333.15 ºK. The polyphenols (caffeoyl derivatives and flavonoids) and methylxanthines (caffeine and theobromine) were analyzed in the extract obtained from the supercritical extraction and compared with Yerba Mate before and after extraction. HPLC methods using Diode Array Detector were employed. The results indicated that only caffeine was extracted from the vegetal drug (Yerba Mate) This method lead to the development of a Yerba Mate product with lower caffeine amounts, but without altering the antioxidant compounds content.