Anacardium occidentale L. leaves extraction via SFE: Global yields, extraction kinetics, mathematical modeling and economic evaluation

The purpose of this work was to obtain extracts from Anacardium occidentale leaves using supercritical fluid extraction (SFE). The use of ethanol and isopropyl alcohol as co-solvents was evaluated. Mass transfer kinetics experiments were performed, and overall extraction curves were modeled. SFE process was compared with different low pressure solvent extraction processes in terms of global yield and the composition of the extract. The techniques used as low pressure solvent extraction processes were: Soxhlet extraction, agitated bed extraction, ultrasound assisted extraction using ethanol as the solvent and hydrodistillation. The extracts were analyzed by thin layer chromatography (TLC) using different eluents. Finally, the economic evaluation was conducted using the software SuperPro designer 6.0® to simulate the process and to estimate the cost of manufacturing (COM) of SFE extracts. The results indicated the presence of essential oils, flavonoids and antioxidant compounds in all the extracts. The higher yield of extract was obtained with the ultrasound assisted extraction. However, the samples with more functional compounds were verified in the SFE extracts and the extracts showed low COM. The model that best described the overall extraction curves for the SFE process was the Sovovل model, which showed minimum values for the sum of the squares of the residues.