Supercritical fluid extraction from guava (Psidium guajava) leaves: Global yield, composition and kinetic data

The aim of this work was to obtain guava leaf extracts using supercritical fluid extraction. The use of ethanol and isopropyl alcohol as co-solvents was evaluated. In addition, mass transfer kinetics experiments were carried out and overall extraction curves were modeled. The global yield and extract composition from supercritical fluid extraction were compared with those from conventional extractions. The extracts were analyzed by thin layer chromatography (TLC) and gas chromatography–mass spectrometry (GC–MS). The results indicated the presence of essential oils, flavonoids and anti-oxidant compounds in all extracts. The highest global yield was observed with the Soxhlet extraction process. However, the extracts from supercritical fluid extraction had higher levels of functional compounds. Overall, the Sovová model best described the overall extraction curves.