Abstract: Orange peel oil was extracted by supercritical fluid-CO₂ (SCF-CO₂) and its constituents were analyzed by GC-MS. The effects of extraction time, pressure, temperature, CO₂ flow rateand separate temperature on the oil yield were studied. The optimal conditions were determined by orthogonal experiments. The optimal conditions were as follows: extraction time 60 min, extraction pressure 20 MPa, extraction temperature 40 ℃, separation temperature 50 ℃. At the conditions, the oil yield was 0.86%. GC-MS analysis revealed that the main constituent of the oil was 5,5'-dimethoxy-3,3'-dimethy-2,2'-bina-phthalene-1,1',4,4'-tetrone which amounted to 35.54%, and the other main constituent was β-hydroxy-methyl-norethisterone-methyl-oxime which amounted to 24.60 %.

Key words: orange peel oil, extraction, SCF-CO₂, GC-MS