EFFECT OF OIL EXTRACTION WITH SUPERCRITICAL CO2 AND ORGANIC SOLVENTS ON ANTIOXIDANT CAPACITY AND TOTAL PHENOLIC CONTENT OF Mucuna MEAL

The antioxidant capacity and total phenolic content of defatted and raw meals of three different varieties of Mucuna seeds (aterrima, cinerium and deeringiana) were investigated. Oil extraction was performed with supercritical CO2, dichloromethane and hexane. Supercritical fluid extraction was carried out at 313 K and 333 K in the pressure range from 15 MPa to 25 MPa. The DPPH (2,2-diphenyl-1-picryl-hydrazyl) assay always revealed a positive influence of oil removal on the antioxidant activity of the meals (i.e.; a negative influence on EC50) for all the considered varieties of Mucuna. The highest content of total phenols in the defatted material was approximately 18-26 % higher than those found in the raw meals (approximate to 4.3-5.5 g GAE/100 g) when examining samples of the same Mucuna variety. A non negligible role of the oil extraction method in the total phenolic content of defatted Mucuna was evidenced in 2/3 of the examined varieties. The oil extraction yields were determined at all the investigated conditions, but the best results were obtained when using the organic solvents (approximate to 15.2-7.4 %).