Development of supercritical carbon dioxide extraction method applied for thick peel of Daidai (Citrus aurantium)

Daidai has pleasant smell, which has been widely used for food industry. Recovery of the essential oil of daidai is difficult bacause the peel was thick. Fresh daidai peel was used as a starting material to extract the essential oil using supercritical carbon dioxide (SC-CO2) through the dynamic and static method. SC-CO2 extraction was carried out under the conditions at temperatures of 40, 60 and 80 o C, pressures of 10, 20 and 30 MPa. The static period of swelling was set for 10, 15, 30, 60 and 90 minites, respectively. The difference in yield of daidai essential oils were hardly observed between 60 and 90 minites, the yield was increasing with swelling time. The optimum condition of dynamic extraction was the temperature at 80 o C and the pressure of 20 MPa which the yield was reached to 27.8 % for the amount of steam destillation oil. While the optimum condition of static extraction was the same condition of dynamic extraction. However, its yield was considarably high, and also extended 95.4 %. Through the static method, more than 3.4 times yield was achieved at the same period. In addition, CO2 consumption was reduced to 38%.