Supercritical carbon dioxide extraction of Cosmos sulphureus seed oil with ultrasound assistance

A hybrid procedure using ultrasound-assisted supercritical CO2 extraction (UASCE) was developed to recover Cosmos sulphureus seed oil (CSSO). Optimization of CSSO extraction was executed by the Taguchi approach. The maximum oil yield (193.1 +/- 4.4 mg/g, dry mass) was obtained at 75 dynamic extraction time, 25 MPa pressure, 55 celcius temperature, 0.5 g/min CO2 flow rate, and 0.2 W/mL ultrasound energy density (UED). Scanning electron micrograph (SEM) revealed that a remarkable porous and loose microstructure was observed in UASCE-treated sample, this may have positive effects on oil release. CSSO acquired by UASCE had higher global yield and higher contents of unsaturated fatty acids, tocopherols, sterols, phenols, and exhibited better physicochemical char- acteristics, antioxidant activity and oxidation and thermal stability compared to CSSO acquired by traditional techniques. Furthermore, the kinetics study highlighted that the employed Sovov ' a models fitted well with the extraction kinetics behaviors. The extraction transport primarily contributed from convective mechanisms during the UASCE process and ultrasound clearly increased mass transfer coefficients and abridged the char- acteristic extraction periods. Consequently, UASCE can be considered a high-performance and sustainable technique for plant oil extraction in food and dietary supplement industries. Cosmos sulphureus is a potential good source of edible oil due to its excellent nutritional properties.