Abstract: In the extraction of nomilin from orange peel with supercritical CO2, four operating parameters including time, temperature, pressure and entrainer (anhydrous ethanol) amount that affect extraction yield of nomilin were investigated using response surface methodology (RSM). A mathematical model describing the relationship between them was set up. The operating parameters could be ranked in decreasing order of influence as follows: time, pressure, temperature and entrainer amount. Response surface analysis of the developed model showed that the optimal extraction conditions were 2 h, 50 ℃, 30 MPa and 1.51 mL/g entrainer amount. Under the conditions, the predicted and experimental extraction yields of nomilin were 54.26 mg/kg and 53.87 mg/kg, respectively, showing no significant difference. Moreover, the experimental data were well fitted with the developed model.

Key words: nomilin, process, optimization, response surface methodology, supercritical carbon dioxide