Authors : A. Adewuyi , R.A. Oderinde and I.A. Ajayi
Abstract: The effect of refining methods on the physico-chemical properties of Baphia nitida (BN) and Gliricidia sepium (GS) were examined. The refining methods used include alkali refining, bleaching and degumming treatment. The seeds were also subjected to standard chemical analysis to evaluate their properties. Proximate analysis indicated low moisture content in the 2 seeds. The ash content of BN (2.17±0.10%) was low while that of GS (4.06±0.80%) was slightly higher than the range recommended for compounding of animal feed. The crude protein content (18.72-20.30%) and carbohydrate content (41.58-45.41%) were fairly high. The oil content was appreciably high and the physico-chemical properties showed the free fatty acid value to be 1.50±0.20% in BN which reduced to 0.52±0.10% after bleaching and in GS it was 0.80±0.10% which also reduced to 0.40±0.50% after bleaching. The peroxide values of all the alkali refined oils were higher than that of the crude which shows some level of degradation. Triglycerol was the dominant lipid species in the oils. The refining methods used increased the diacylglycerol, monoacylglycerol and triacylglycerol content of the oils while the polar and sterol content reduced. The concentration of the macronutrients were high with K (627.21±0.80 ppm) being the highest in BN. The concentration of the trace metals also differs with Mn (32.30±0.39 ppm) being the highest in GS. The seeds are good sources of oil and minerals and there is the possibility of considering them as feed supplements and their oils in industrial applications. Out of all the refining methods used, bleaching appeared to be the best technique for refining in terms of stability and improvement of physico-chemical properties of the oils.
A. Adewuyi , R.A. Oderinde and I.A. Ajayi , 2009. The Metal Composition, Proximate Properties and the Effect of Refining on the Physico-Chemical Characterization of Baphia nitida and Gliricidia sepium Seed and Seed Oil. Journal of Food Technology, 7: 43-49.