Supercritical carbon dioxide extraction of quinoa oil: Study of the influence of process parameters on the extraction yield and oil quality

The supercritical CO2 extraction of oil from four different quinoa varieties has been studied in this work. For this purpose, the influence of extraction temperature (40-60 degrees C), pressure (20-40 MPa) and raw material size (250-1000 mu m) on the extraction rate has been considered. The extraction rate resulted to be faster the higher the pressure whereas the temperature had less influence on the extraction kinetics. The experimental data were modelled using the Sovova's kinetic model. The quality of the oil extracted has been evaluated in terms of antioxidant activity (AA), fatty acid profile and tocopherol content. The highest AA was obtained for quinoa oil extracted at 40 MPa and 40 degrees C; this oil presented high content of polyunsaturated fatty acids (63% of the total) and significant amount of tocopherols (2.5 mg/g oil). Quinoa oil extracted using CO2 presented higher antioxidant capacity and tocopherol content than quinoa oil extracted with hexane, regardless the quinoa variety used.