Author
 |
Dunford, Nurhan |
|
King, Jerry |
|
Submitted to: Intl Symposium on Supercritical Fluid Chromatography and Extraction
Publication Type: Abstract Only Publication Acceptance Date: 4/8/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Phytosterols are common to many plant derived oils but represent only a very small fraction of the total oil composition. Previous studies have shown that rice bran oil and derivative products are an excellent source of nutritionally beneficial ingredients, such as sterols, tocopherols, tocotrienols, and oryzanol (ferulate esters of plant sterols), all of which hare claimed to have cholesterol reducing properties. Unfortunately, crude rice bran oil contains higher levels of free fatty acids than many other vegetable oils, due to the presence of high levels of an active lipase which promotes hydrolysis of oil to the free fatty acids. Conventional refining processes to remove the free fatty acids can result in a significant reduction of active rice bran oil components; consequently, a high pressure fractionation process employing supercritical carbon dioxide was examined as an alternative process for reducing the free fatty acid content and concentrating the above components. An 8-foot column, packed with Propak internals and operating semi-continuously, was used to remove free fatty acids from the crude oil. Compositions of the extract and raffinate fractions from the column were analyzed for steryl esters, free sterols, and oryzanaol content, as well as total triglyceride and free fatty acid content. The effect of pressure (136-340 Bars), both isothermal and temperature gradient (45-90 deg C) operation of the column, carbon dioxide flow rate, and fractionation time on the composition of fractions were examined. The phytosterol content of a product from SC-CO2 fractionation column was compared with a refined rice bran oil and phytosterol enriched margarine. |
