Two-step extraction of pumpkin seed oil with supercritical CO2 and subcritical propane: the yield, kinetics and profile of fatty acidsCör Andrejč, Darija (Avtor) Knez, Željko (Avtor) Kotnik, Petra (Avtor) Knez Marevci, Maša (Avtor) supercritical CO2 extractionproprane extractionBrunner modelfatty acidchromatographyPumpkin seed oil is oil rich in oleic, linoleic, and palmitic acids fatty. In our study, a two-stage extraction method has been used to encourage a higher yield and the quality of the oil. The first step was carried out with supercritical carbon dioxide (scCO₂) in the pressure range from 200 bar to 800 bar and temperatures of 40 °C and 60 °C. For the second step subcritical propane was used, at a pressure of 50 bar and 100 bar, and the same temperatures that were used previously for the first step of scCO2 extraction. The extraction kinetics were modelled using Brunner’s semi-empirical approach, which showed good agreement with the experimental data (R² > 0.97), confirming its suitability for both solvents. The combination of both extraction steps increased the overall yield, with the highest value of 45.3% obtained within the investigated pressure range (200–800 bar) at conditions of 600 bar and 60 °C (scCO₂) and 100 bar and 60 °C (propane). An analysis of the fatty acids (FA) by gas chromatography (GC) showed a stable fatty acid profile dominated by oleic acid (up to 48.56%), followed by linoleic acid. The second extraction step with propane enabled recovery of the residual oil remaining in the matrix successfully after the scCO₂ extraction. The presented integrated approach demonstrates that sequential application of environmentally friendly solvents can increase the overall recovery of pumpkin seed oil while providing solvent-free extracts with a high content of unsaturated fatty acids.Elsevier B.V.20272026-09-04 12:21:32Članek v reviji100117UDK: 66.02COBISS_ID: 288999939DOI: 10.1016/j.supflu.2026.107105ISSN pri članku: 1872-8162sl© 2026 The Authors