Lipids and other constituents of Vigna unguiculata and Phaseolus vulgaris grown in northern Nigeria

Dried edible seeds of six varieties of Vigna unguiculata and two of Phaseolus vulgaris grown and consumed in the Savannah region of Northern Nigeria were analysed for their chemical constituents. Proximate composition values for V. unguiculata and P. vulgaris, respectively, were as follows: moisture 6.20–8.92%, 4.23–4.42%; protein 20.5–31. 7%; 31.1–33.1%; fat 1.14–3.03%, 1.02–1.22%; fibre 1.70–4.5%, 2.81–3.23%; and carbohydrate 56.0–65.7%, 55.5–57.2%. Seven components were identified by TLC separation of the fat. While the saponification numbers and acid values of the oils from the Vigna spp. were lower than those of the Phaseolus varieties, the iodine numbers were higher in the Vigna. Overall, potassium was the most abundant element in the seeds. Total cyanide, tannin, total oxalate and phytate were found in varying amounts, while 16 amino acids were identified. This paper highlights the safety and high nutritive values of these local varieties.