Iron contents and some physical components of twelve cowpea varieties

Abstract

Twelve Nigerian cowpea varieties were investigated for physical properties, iron contents and dialysable iron. The seed coat accounted for 5.8-11.4% of the weight of the seeds, leached solids 5.1-13.6%, swelling capacity 43.9-94.5% and the seed density ranged between 0.91-1.28g/cm³.

There were significant differences (P < 0.05) in the iron contents of the whole, peeled, cooked and soaked cowpea samples. While processing procedures such as seed coat removal did not significantly affect the dialysable iron, cooking of the beans led to significant increases in the diffusibility of iron. However, the addition of ‘Kanwa’, an alkaline salt, lowered the dialysable iron significantly (P < 0.05). The implications of these results on the diets of Nigerians in relation to iron nutrition are discussed.