Evaluation of yerba mate fruit pulp total and fractioned soxhlet extraction using thermal analyses.

Ilex paraguariensis leaves are traditionally used to prepare hot or cold beverages in South America. Yerba mate fruit pulp has no commercial value, nevertheless, its extract showed different biological activities. The fruits contain high concentration of saponins and methylxanthines, besides polyphenols and anthocyanins. Soxhlet extraction using polarity gradient of solvents is used to perform total and fractioned extraction of plant material. Thermal analyses are used to evaluate extracts by revealing their behavior when submitted to temperature variation. The aim was to evaluate by thermogravimetry coupled to mass spectrometry extracts from yerba mate semi-ripe fruit pulp, obtained by Soxhlet extraction using diethyl ether, ethyl acetate, ethanol and water solvents. TGA/MS was applied using air atmosphere. Diethyl ether and ethyl acetate showed thermal behavior similarity, indicating similar composition. Only the aqueous extract showed inorganic compounds with approximately 20% of ashes. Ethanolic extract showed more apparent differences of thermal behavior, with the greater mass loss event related to the release of CO2, indicating greater amount of more thermal stable compounds. The other extracts showed their main event related to the loss of CO. Ethanolic extract also showed a greater number of events, being the most complex extract