Supercritical carbon dioxide extraction of fatty and waxy material from rice bran

Waxy and fatty materials were removed from rice bran by supercritical carbon dioxide at pressures up to 28 MPa and temperatures between 40 and 70 degrees C. The yields of the supercritical extraction were only 16-60% of those obtained by Soxhlet extraction with hexane. The highest yield was reached at the highest pressure and temperature used (28 MPa and 70 degrees C), indicating that supercritical extraction of this lipid-bearing material could probably be improved at more severe extraction conditions,The supercritical extract obtained at operational conditions giving high yield was chromatographically characterized. Compared to the hexane extract, the supercritical extract was lighter in color and richer in wax content and long chain fatty acids C-20-C-34. Triacontanol was the most abundant alcohol in both extracts. Tocopherol contents were similar.