PRODUCTION OF TOCOPHEROL CONCENTRATES BY SUPERCRITICAL-FLUID EXTRACTION AND CHROMATOGRAPHY

Supercritical fluid extraction (SFE) has been combined with supercriti cal fluid chromatography (SFC) in a preparative mode to develop a syst em for fractionating and enriching high value constituents contained i n seed oil matrices. The system consists of an extraction step sequenc ed on-line with a sorbent filled column, which permits a SFE-enriched tocopherol fraction to be diverted onto the chromatographic column for further enrichment of the tocopherols. For the SFE stage, the tocophe rol enrichment was optimized at 25 MPa and 80 degrees C for soybean fl akes and rice bran. However, total tocopherol recovery and enrichment was also found to be a critical function of the mass ratio of CO2/seed charge. Approximately 60% of the available tocopherols in soyflakes c an be recovered in the SFE step, yielding enrichment factors of 1.83-4 .33 for the four tocopherol species found in soy-bean oil. Additional enrichment of tocopherol species can be realized in the SFC stage, ran ging from 30.8 for delta-tocopherol to 2.41 for beta-tocopherol.