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Title: PREPARATIVE-SCALE SUPERCRITICAL FLUID EXTRACTION/SUPERCRITICAL FLUID CHROMATOGRAPHY OF CORN BRAN

Author
item Taylor, Scott
item King, Jerry

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary: Consumers have become increasingly aware of the effect of the nutritional content in foods they consume on their overall health. Nutritional supplements and functional foods are becoming highly desired by the public as important agents for maintaining a healthy life style. The isolation of high value components for the functional food and nutraceutical markets in a benign manner, using non-toxic solvents, is desired with respect to consumer and environmental safety issues. Therefore extraction and fractionation processes using high pressure carbon dioxide and ethanol are particularly attractive for these purposes and have been used in this study to isolate phytosterols from corn bran. The results of this research offer a route to enriching phytosterols, which can lower cholesterol in humans, from vegetable oils. In particular, a processing procedure using only compressed carbon dioxide and ethanol, which are generally regarded as safe (GRAS) agents, allows the enrichment of these phytosterols from vegetable oils, allowing the derived extracts to be safely reformulated back into a variety of functional foods. Unlike some conventionally-used processing methods, the described processing technique is compatible with the environment, reducing solvent emissions into the air and water.

Technical Abstract: A preparative-scale supercritical fluid extraction/supercritical fluid chromatography (SFE/SFC) procedure has been developed for the removal of the oil from corn bran to obtain fractions enriched with ferulate-phytosterol esters (FPE). Operational parameters from an analytical-scale supercritical fluid fractionation technique were translated to and optimized on a home-built, preparatory-scale SFE/SFC apparatus. SFE was performed at 345 bar and 40C using supercritical carbon dioxide. These conditions did not exhaustively extract the corn bran, but yielded about 96% of the available oil. SFC was conducted in three steps, followed by reconditioning of the sorbent bed. The first SFC step was conducted with neat CO2 at 690 bar and 80C, while the second step was performed at 345 bar and 40C using 10 mol% EtOH/CO2. A third fraction was then collected at 345 bar, 40C using 15 mol% EtOH/CO2. Column reconditioning was performed at 690 bar and 80C to purge the column of any residual ethanol and corn bran oil components. Preparative-scale SFE/SFC of corn bran produced a fraction significantly enriched in free sterols and FPE, suggesting that such a scheme could be used industrially to prepare a functional food additive.