Reduction in the cholesterol content of butter oil using supercritical ethane extraction and adsorption on alumina

In order to assess the capacity of supercritical fluids in reducing the cholesterol content of dairy products, experimental data on the extraction of butter oil with supercritical ethane were obtained at 40, 55, and 70°C and pressures ranging from 8.5 to 24.1 MPa, using a semi-continuous flow, high-pressure apparatus. In order to enhance the cholesterol removal process selectivity, the extraction operation was subsequently coupled to adsorption on alumina. The solubilities of cholesterol and butter oil in supercritical ethane were found to be much higher than those in supercritical CO2. The combined extraction/adsorption process resulted in butter oil fractions with a cholesterol content limited to about 3% of that in the original oil. Selective blending of these low-cholesterol fractions can provide yet further possibilities in the formulation of high value products.