Extraction of corn germ oil with supercritical CO₂ and cosolvents

The aim of this work was to investigate corn germ oil extraction using supercritical CO₂ and cosolvents addition (hexane, acetone and ethanol). The effects of temperature (45-85 °C) and pressure (15-25 MPa) on the extract yield were evaluated for the tests conducted only with supercritical CO₂. The addition of cosolvents to supercritical CO₂ was also examined at 25 MPa and 60 °C. The conventional Soxhlet extraction with different organic solvents was also performed for comparison purposes. The results of extraction with supercritical fluid showed that the yields increased with pressure at each temperature, but decreased with temperature increase. Mathematical modeling was applied to describe extraction curves, with very good fits. The addition of cosolvents led to higher yield, with a maximum yield of 13.81% using ethanol. The analysis of fatty acids profile did not present significant differences among the evaluated methods. On the other hand, the antioxidant activity of the extracts obtained by supercritical CO₂ extraction was higher than the ones verified for the extracts collected after conventional Soxhlet extraction. Therefore, the use of supercritical CO₂ extraction could be an interesting way to preserve antioxidant properties of this oil in order to use it for pharmaceutical purposes.