Cattle brain is rich in cholesterol. The conventional methods of cholesterol extraction from cattle brain involve use of large quantities of chlorinated solvent. Detailed investigations were made on the extraction of cholesterol from cattle brain using supercritical carbon dioxide (SC CO2) and with different cosolvents. Effect of process parameters like temperature of extraction, mass flow of the solvent, particle size and effect of cosolvent were studied. Extracted cholesterol was characterised for its purity by gas chromatography (GC) and structure using differential scanning calorimetry (DSC), infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). The extracted cholesterol can be used for biochemical synthesis. The low-cholesterol product obtained after SC CO2 extraction can be used for human and animal consumption after screening for bovine spongiform encephalopathy (BSE). (C) 2004 Elsevier B.V. All rights reserved.