Gas chromatography-mass spectrometric determination of fatty acids in seed oil of winged bean (Psophocarpus tetragonolobus (L.) DC).

Abstract

Fatty acids of winged bean seed oil were examined by gas chromatography-mass spectrometry of their pyrrolidide derivatives. Oleic and linoleic acids were determined to be the major unsaturated fatty acids in the oil. Long chain saturated fatty acids, such as behenic and lignoceric acids, were found in relatively high amounts as compared with other edible seed oils. The fatty acids that could not be separated by gas liquid chromatography were identified as linolenic acid and arachidic acid respectively on mass spectrometric analysis. Parinaric acid, previously reported by Cerny et at., was not detected and this supposed fraction was instead found to be eicosenoic acid. Erucic acid, suspected of having an adverse effect on myocardial lesions in rats, was detected but only in small quantity. The identifications of these unsaturated fatty acids were further confirmed by deducing the location of the double bonds in their moieties. From these findings, winged bean seed oil can be suggested as being a food source of favorable quality.