Obtenção de compostos fenólicos de plantas brasilieras via tecnologia supercrítica utilizando cossolventes e extração assistida por ultrassom

Abstract

The objective of this study was to use supercritical fluid extraction (SFE) to extract phenolic compounds from indigenous Brazilian plants with high economic potential. The plants studied were: Flame wine (Pyrostegia venusta), Dog´s knot (Heteropteris aphrodisiaca O. Mach), Ice-cream bean tree (Inga edulis), Jatoba (Hymenaea courbaril var. stilbocarpa) and beans (Phaseolus vulgaris L.). Global yields experiments (X 0,S/F=50 ) using pure CO 2 , CO 2 + ethanol (10 %, mass) and CO 2 + water (10 %, mass) as solvents were performed 35 MPa and 323 K; the ratio of the CO 2 mass to feed mass was maintained constant (50 kg/kg). The extracts were analyzed by thin layer chromatography (TLC). Their antioxidant activity, total polyphenolic and flavonoids content were also determined. After evaluating the behavior of the yield and chemical composition of the extracts, it was observed that the solvent mixture CO 2 + H 2 O provided higher yield, especially for jatobá. Additionally, this extract presented high antioxidant activity. Based on these results, global yields isotherms (GYI) of jatoba were determined at temperature of 323 and 333 K and pressures of 15, 25 and 35 MPa in order to select the optimum operational conditions. Due to the higher polyphenols and tannins content, the optimum conditions selected were 15 MPa and 323 K. Overall extraction curves (OEC's) were obtained under these conditions in order to determine the kinetic parameters by fitting the OECs to a linear spline with three straight lines. For the scale-up study, the criterion adopted was keeping constant the solvent to feed ratio (S/F) and process time. The chemical analyses of SFE extracts were performed by Ultra performance liquid chromatography -diode array detection (UPLC-MS/MS) and electrospray ionization mass spectrometry (ESI-MS/MS). According to the results, the extracts showed chemical profile xvi of procyanidins. Finally, it was evaluated the cost of manufacturing (COM) of the extracts for all five plants obtained in the GYI experiment (X 0, S/F=50 ) for the three solvent: CO 2 pure, CO 2 + ethanol (10 %, mass) e CO 2 + water (10 %, mass); and for the jatobá extract obtained at optimized process conditions using CO 2 + water (10 %, mass). The estimated COM demonstrated the feasibility of the SFE process for industrial scale extractors of 50 and 500 L, depending on the raw material to be processed. Moreover, according to the estimated COM, obtaining jatobá bark extracts rich in tannins was economically feasible with CO 2 + H 2 O. Jatoba extracts were also obtained using ultrasound assisted extraction (UAE). The extractions were performed at the potency of 20 and 60 W during 40 min, using water at S/F ratio of 20 (optimized in a maceration extraction assay). High content of polyphenols were obtained using the potency of 60 W. The efficiency of UAE in extracting polyphenols was evaluated using crosscurrent extraction in three stages. The scale-up of the UAE process was studied in an extractor of three liters. It was also performed a kinetic study to...

Obtenção de extratos com bixina a partir de sementes de Urucum desengorduradas

“…Os procedimentos de extração comuns utilizados no isolamento de compostos orgânicos de plantas medicinais são: hidrodestilação, maceração, extração com solvente a baixa pressão (LPSE), entre outros (VEGGI, 2013).…”