Fatty Acid Composition of White Mustard Seed Oil by Urea Fractionation and Gas-Liquid Chromatography
Abstract The detection of C20 to C26 polyunsaturated fatty acids in a Cruciferae seed oil (white mustard) is possible when these methyl esters are concentrated by urea fractionation. The detection and estimation of fatty acids present in trace amounts (< 0.1%) was simplified by quantitative removal of other fatty acids with similar gas chromatographic retention times. Odd and even chain length di- and tri-unsaturated fatty acids were tentatively identified in white mustard seed oil. A tetraenoic acid, presumably arachidonic acid, was tentatively identified for the first time in a plant lipid of the highest evolutionary level, i.e., angiospermae. More easily extracted “free” lipids have a significantly different fatty acid composition than the more difficult to extract “bound” lipids.