Determination of optimum conditions for SC-(CO2 + ethanol) extraction of β-carotene from apricot pomace using response surface methodology

Supercritical carbon dioxide (SC-CO2) extraction of β-carotene from apricot pomace obtained in apricot purée production process was investigated in the presence of an entrainer. Before response surface methodology (RSM) was applied, the effects of temperature, pressure, static extraction time, and type of entrainer on the amount of β-carotene extracted were studied. Ethanol was chosen as entrainer to obtain the best result. In the RSM, temperature, pressure and ethanol percentage (v/v) were critical components. RSM experiments were performed at the range of temperature 316-350 K, pressure 13.3-47.3 MPa, ethanol percentage 2-28% for three parameters. Optimum amount of β-carotene extracted was obtained as 100.4 μg/g dry pomace with employing the following predicted optimum extraction conditions: temperature 342 K, pressure 31.1 MPa and ethanol percentage 27.4%. A verification experiment, conducted at these optimized conditions for maximum extraction of β-carotene, produced value for amount of β-carotene (98 μg/g dry pomace) that was very close to predicted value, indicated the reliability of the empirical model.