Research-Article| Volume 72, ISSUE 10, P2834-2840, October 1989

Removal of Cholesterol from Milk Fat Using Supercritical Carbon Dioxide1

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      The ability of supercritical fluids to dissolve materials of low volatility was reported 109 yr ago. This technology has received increased attention lately because of increased energy costs, questioned use of organic solvents, and separation problems that defy solution. Supercritical fluids have enhanced solvent power as a liquid but also behave as gases with no surface tension. Selectivity of supercritical CO2 for cholesterol is a temperature-dependent and pressure-dependent phenomenon.
      In studies using ascending pressure profile extraction, milk fat contained in the extraction chamber was stripped of 90% of its cholesterol. Efficiency of separation was measured on each fraction collected at each pressure interval. Cholesterol was assayed using an AOAC procedure and gas chromatography. Distribution coefficients and selectivities calculated for two processes that were ideal in separation efficiency indicated that cholesterol can be effectively separated. Fatty acid composition plays a key role in supercritical extraction; short-chained acids complicate extraction.


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