Oil content and fatty acid composition of some underutilized legumes from Nigeria

Abstract

Three underutilized legumes from Nigeria, Brachystegia eurycoma, Tamarindus indica and Mucuna flagellipes, have been subjected to standard analytical techniques in order to evaluate proximate composition, physicochemical properties and contents of nutritional valuable elements and fatty acids of the seeds and oils. The proximate analysis indicated that the oil content was 5.87 ± 0.30, 7.20 ± 0.45 and 3.77 ± 0.21 g/100 g for B. eurycoma, T. indica and M. flagellipes, respectively. The seeds are rich in protein and carbohydrate, the protein content ranging from 11.82 ± 0.25 g/100 g–24.94 ± 0.18 g/100 g dry matter. These compare favourably with high protein animal sources like oyster, beef, pork and marine fishes. The iodine value of two of the oils place them in the non-drying group of oils, while the composition of all the oils compare well with those of rape seed, sesame, sunflower and groundnut seed oils. This suggests their use as edible oils. Analyses of the oils for fatty acids indicate that the oils contain linoleic acid which is one of the three essential fatty acids. The dominant fatty acids however are linoleic, palmitic, oleic and stearic acids with oleic acid having the highest percentage 24.13–31.50%. Eight nutritional valuable minerals were determined in the seed flours. The seeds are rich in potassium 52.1 mg/100 g–131 mg/100 g. They also contain significant concentration of iron 4.55 mg/100 g–8.20 mg/100 g.