response surface methodology for optimization of supercritical fluid extraction of orange peel essential oil

Background: orange peel essential oils were obtained using supercritical fluid extraction. this method is an important high scaling extraction method used for the extraction of plant and animal extracts. objectives: the aim of this study was the optimization of the extraction of the orange peel essential oil. methods: the experimental parameters of supercritical fluid extraction (sfe) such as temperature, pressure, and extraction time, and modifier volume were optimized using a central composite design after a 24-1 fractional factorial design. orange peels were collected from ripe orange and were washed, air dried, and milled. then, a suprex mps/225 system in the sfe mode with a maximal operating pressure of 395 bars was used for essential oil extraction. moreover, gc-ms and gc-fid were used for the identification and determination of oil compounds, respectively. results: eight compounds have been identified based on their retention indices and mass spectra. according to the results, α-pinene, β-pinene, myrcene, d-limonene, terpinolene, c8-aldehyde, citronellol, and linalool were identified in orange peel essential oil. the optimum sfe conditions were obtained at a pressure of 347.07 atm, temperature of 55° c, extraction time of 30.16 min, and ethanol volume of 147.05 μl. moreover, extraction yields based on sfe varied in the range of 0.04% to 1.18% (w/w). conclusion: the results showed supercritical fluid technology as the best alternative technique for the extraction of pure and high-quality essential oil from orange peel. it is a green method and does not have any environmental impact.