Separation of oryzanol from crude rice bran oil.

摘要

The separation of oryzanol from crude rice bran oil was investigated with the ultimate goal of industrial application. The oryzanol was concentrated from the crude oil and then isolated by silica gel column chromatography. Preparation of the oryzanol concentrate was attempted by the extraction of unsaponifiable matter, solvent extraction and step-wise elution chromatography. Methanol, ethanol and dimethylformamide were each evaluated for the solvent extraction. The column chromatographic separation was optimized with respect to mobile phase, flowrate, column height, and column width.; The dimethylformamide extraction of the crude oil proved to be the optimal method of oryzanol concentration with respect to oryzanol recovery and concentration in the extract. This method produced a fraction containing 8.4 {dollar}pm{dollar} 0.6% oryzanol, concentrating oryzanol by a factor of 9.7 {dollar}pm{dollar} 0.6 from the crude oil. The column chromatographic system, with the mobile phase toluene/ethyl acetate 90:10 by volume, separated oryzanol from the less polar compounds in the extracted concentrate. However, oryzanol could not be isolated from the more polar components. Variations in flowrate, column height, and column width did not significantly enhance the separation.; Scale-up of the dimethylformamide extraction did not affect oryzanol recovery. Furthermore, extractions with fresh and recycled solvent showed no difference in the extracted oryzanol concentrate. Therefore, pilot-plant scale-up of this extraction should be considered. Isolation of oryzanol from the concentrate by column chromatography should be further investigated with the use of reverse-phase silica as the adsorbent.