GC–MS, 1H and 13C NMR, and physiochemical properties of oils of Dacryodes Edulis and Persea Americana

AbstractA comparative investigation was carried out on the seed oils of P. americana and D. edulis for their physiochemical properties and spectroscopic properties. Oils were extracted from the respective powdered seeds using Soxhlet extraction technique giving 18.63% and 45.49% yields for P. americana and D. edulis, respectively. The seed oils were subjected to physiochemical analysis using standard protocols as prescribed by the American Oil Chemist Society (AOCS) and the American Society for Testing and Materials (ASTM). The fatty acid content was determined using Gas Chromatography, Proton (1H) and Carbon-13 (13C) Nuclear Magnetic Resonance spectroscopy. The results indicates that linoleic acid is the most unsaturated fatty acid, while stearic acid is the most saturated fatty acid in both oils. Unsaturated fatty acid peaks for olefinic H were observed at 5.34 and 5.31 ppm for P. americana and at 5.43 and 5.32 ppm for D. edulis oils in 1H-NMR. For 13C-NMR, the presence of C with triple bond attached to an alkyl group was observed at 85 ppm for the P. americana, while similar peak was observed for D. edulis at 128.21 to 130.1 ppm. The chemical characterization of the oils gave iodine values of 51.86 mgI2/g for P. americana oil and 48.72 mgI2/g for D. edulis oil. Similarly, acid values of 3.45 mg KOH/kg and 5.76 mg KOH/kg were obtained for P. americana and D. edulis seed oils respectively. The physiochemical and spectroscopic results obtained showed that P. americana and D. edulis seed oils have the potential for use in a number of industrial applications.