Fourier Transform Infra-Red (FT-IR) Characterization of Plant Oils from Selected Cultivars Grown in Nigeria

Abstract

Background and Objectives: The developments of fourier transform infrared (FT-IR) spectroscopic instrumentation, and application, over the years has made it a powerful analytical tool in the study of oils and fats. This work has explored fourier transform Infra-Red for characterization of plant oils from selected cultivars grown in Nigeria. The selection of these plants oils that flourishes in Nigeria aside their used primarily for nutritional applications, is dependent on the fatty acid (FA) composition of triacylglycerol (TAG which make them potential for bioenergy and biofiuel production considering the explosion of energy demand through alternative energy sources. They are also needed for the preparations of chemical feedstocks, biopolymer and composites, skin care products. Oils from these plants can provide renewable sources of high-value fatty acids for both the chemical and health-related industries. We report here several areas where these plant oils can have a significant impact on the emerging bioeconomy. Materials and Methods: The samples were each placed in contact with KBr disc and FT-IR spectra were collected in frequency 4500-400 cm-1 by coadding 32 scans and at resolution of 4 cm-1. All spectra were rationed against a background spectrum. In each scan, a new reference background spectrum was detected. Results: The spectra of oils of the present investigation revealed the following bands 1522, 1449.55, 1364.68, 1444.73, 1364.68, 1445.09, 1369.50, 1447.62, 1362.75, 1449.55, 1371.43, 1447.62, 1366.54, 1447.62, 1450.5, 1360.82, 1370.47, 1446.66, 1246.06, 1364.47, 1448.59 for Adansonia digitata, Ricinus communis, Sesamum indicum, Jatropha curcas, Allium cepa, Cucumis melo, Lannea microcarpa, Lagenaria vulgaris and Sesamun indicum seed oil respectively. 1450 cm-1- 1444 is related to bending vibration of CH2, and CH3; (cis =C–H bending) and at 1360 - 1370 cm-1 is concerned with the bending vibrations CH2 groups which showed total unsaturation. The results obtained shows that all the oils are unsaturated because there is no band around 3005- 3009 which is the band that normally determine the index of degree of unsaturation. Conclusion: The FT- IR spectroscopy proved to be an important technique for identification, analysis, determination of degree of saturation of fatty acids in oils suitable for industrial applications.