Extraction of vetiver (Chrysopogon zizanioides) root oil by supercritical CO2, pressurized-liquid, and ultrasound-assisted methods and modeling of supercritical extraction kinetics

In this study, non-conventional methods of supercritical extraction with CO2 as well as with ethanol or ethyl acetate cosolvent, pressurized-liquid extraction (PLE), and ultrasound-assisted extraction (UAE) were employed to evaluate the extraction of vetiver (Chrysopogon zizanioides) oil in comparison with hydrodistillation and Soxhlet techniques. The highest yields by supercritical CO2 extraction were obtained at 60 degrees C and 20 MPa, 2.23% (m/m), and 2.66% (m/m) with 5% (V/V) of ethanol cosolvent, while PLE and UAE methods allowed a reduction of the time and solvent volume, obtaining up to 83% and 70% of the Soxhlet yields, respectively. The main identified compound in the oil (supercritical extraction, Soxhlet, PLE, and UAE with n-hexane) was sesquiterpene khusimol (29.19% to 32.89%), as well as isovalencenol, alpha-vetivone, and zizanoic acid. The highest antioxidant activity was 71.44 mu mol(Trolox) g(extract)(-1) for the sample obtained by Soxhlet extraction with ethanol1503039CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ151062/2018-