The extract of Pfaffia glomerata or Brazilian ginseng roots (BGR) has several saponins with surfactant activity, of which the most important is beta-ecdysone due to its biological activity. Therefore, the aim of this study was to obtain an extract rich in saponins from BGR using the commercially established low-pressure (that is, extraction performed at ambient pressure) solvent extraction (LPSE) method with and without ultrasound assistance. The effects of the extraction method chosen (LPSE, LPSE assisted by continuous ultrasound, UAE; LPSE assisted by ultrasound at the beginning of the process, BUAE; and LPSE assisted by pulsed ultrasound PUAE), the temperature (40 and 60°C) and the extracting solvents (water, ethanol:water [35:65, v/v], ethanol:water [70:30, v/v], isopropanol:water [35:65, v/v] and isopropanol: water [70:30, v/v]) were evaluated with respect to the global extraction yield (X0), emulsification index (E24) and reduction of water surface tension (RWST) by means of statistical analysis. A kinetic study was performed to determine the best extraction process conditions for each response variable (X0, E24 and RWST). Additionally, beta-ecdysone content was measured for the extracts obtained from the kinetic study. The highest X0 was 64 % (dry basis) obtained by LPSE at 60°C using water as the extracting solvent. Nonetheless, the extract with the largest E24 (approximately 50 %) and RWST (36 %) were obtained by PUAE and BUAE, respectively, at 60°C using isopropanol:water (70:30, v/v) as the extracting solvent. In the kinetic study, it was observed that beta-ecdysone yield ranged from 1.0-1.3 %. This novel process has been further described, and inventor rights have been claimed in an invention patent application (BR 1020130128961).
Keywords: Beta-ecdysone, brazilian ginseng roots, low-pressure solvent extraction, Pfaffia glomerata, saponins, ultrasound assisted extraction.