Reduction in cholesterol and fractionation of butter oil using supercritical CO2 with adsorption on alumina

Cholesterol reduction together with the fractionation of triglycerides in butter oil was obtained using a combined supercritical CO2 extraction/alumina adsorption process in a high-pressure apparatus that allows the independent control of temperature and pressure. Cholesterol levels in butter oil fractions extracted at 40 °C and 27.6 MPa were reduced from 2.5 to 0.1 mg g−1 of oil. Butter oil was also fractionated into low-, intermediate- or high-molecular-weight triglycerides. This single-stage combined process is a clear indication of the important technological possibilities with a more efficient multistage fractionation followed by the subsequent blending and formation of desired milk fat products. A comparison of solubility data of pure cholesterol in CO2 with those for cholesterol contained in butter oil revealed the co-solvency effects of triglycerides on the solvation of cholesterol.