Navegando por Autor "Meireles, Maria Angela Almeida"
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Artigo Anacardium occidentale L. leaves extraction via SFE: Global yields, extraction kinetics, mathematical modeling and economic evaluation(Elsevier, 2013-03-22) Leitão, Nayane Carla Márcia Cavalcanti de Sá; Prado, Helena Carvalho do; Veggi, Priscilla Carvalho; Meireles, Maria Angela Almeida; Courtial, Camila Gambini PereiraThe 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, lavonoids 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 Sovová model, which showed minimum values for the sum of the squares of the residuesArtigo Supercritical extraction to obtain vetiver (Vetiveria zizanioides L. Nash) extracts from roots cultivated hydroponically(David Publishing Company, 2008-10) Courtial, Camila Gambini Pereira; Gualtieri, Isabela P.; Maia, Nilson B.; Meireles, Maria Angela AlmeidaWe determined the global yield and composition of extracts from vetiver roots cultivated hydroponically. We extracted roots of two varieties collected at different times after planting. The extracts were obtained by supercritical fluid extraction (SFE); we also estimated manufacturing costs. Constituents were quantified by gas-chromatography/flame ionization detection (GC-FID). Results demonstrated the efficacy of a hydroponic system in producing vetiver with a high root extract content. The largest yield was obtained from roots collected on days 132 and 92 after planting from varieties National (1.41%) and Bourbon (1.28%), respectively. The major compounds present in the extract were khusimol, isovalencenol, alpha-vetivone and beta-vetivone. To determine the economic viability of producing these extracts, manufacturing costs were estimated using a simplified methodology. The manufacturing costs were US$ 22.26/kg and US$ 24.26/kg for varieties national and Bourbon, respectively