Characterization of Some Under-Utilized Legume Seed Oils by Nmr Spectroscopy

*M. O. Aremu¹, O. Olaofe², E. T. Akintayo² And L. Lajide³

¹Department of Chemistry, Nasarawa State University, PMB 1022, Keffi (Nigeria) ²Department of Chemistry, University of Ado-Ekiti, PMB 5363, Ado-Ekiti (Nigeria) ³Department of Chemistry, Federal University of Technology, PMB 704, Akure (Nigeria)

1H NMR spectroscopy has been employed in the characterization of some under-utilized legume seed oils while the quantitative integrity of the NMR derived fatty acids composition is verified by gas chromatographic analysis of the oils. The peak area ratio of (–CH2–) / (=CCH2C=) in the proton NMR spectra of oils have been used as an index of characterization of oils. The ratios are close for all the oils studied being, 26.4 for dark red coat Vigna subterranean, 21.6 for Kerstingiella geocarpa, 24.8 for moderate brown coat Vigna unguiculata, 24.3 for small white coat Vigna unguiculata and 25.9 for Phaseolus coccineus indicating similarity in the level of unsaturated fatty acids.

Legume seed oil; NMR spectroscopy