Extraction of Mucuna seed oil using supercritical carbon dioxide to increase the concentration of l-Dopa in the defatted meal

The main aim of this investigation was to extract oil from seeds of Mucuna in order to increase the concentration of l-Dopa in the defatted Mucuna meal. Three different varieties of Mucuna (aterrima, cinerium, deeringiana) and solvents (supercritical carbon dioxide, dichloromethane, hexane) were used. The experiments under supercritical CO2 conditions were performed in a laboratory scale unit at 40 and 60 °C over the pressure range from 150 to 250 bar. A constant flow rate of CO2 close to 3 mL/min was always kept. The results revealed that temperature, pressure and density were important variables for CO2 extraction. The concentration of l-Dopa in the defatted meal from supercritical fluid extraction was always higher than those without oil extraction or extracted using organic solvents. Quantitative and qualitative analyses of the oil extracted under the different investigated experimental conditions shown no significant differences in terms of fatty acid and free glycerol compounds. The same analyses indicated linoleic acid (omega-6) as the major oil component and a content of free fatty acids in the oil extracted with supercritical CO2 close to 5%. The kinetics of oil extraction with CO2 was also investigated at all the considered operating conditions.