BIOCHEMICAL EVALUATION OF SOME NIGERIAN LEGUME SEEDS

Two varieties each of bambara groundnut (Voandzeia subterranea (L.) Thouars), kidney bean (Phaseolus vulgaris L.), lima bean (Phaseolus lunatus L.), pigeon pea (Cajanus Cajan (L.) Millsp) and one variety of jack bean (Canavalia ensiformis (L) DC.) seeds grown in Nigeria were investigated for their proximate composition, mineral and amino acid contents, in the raw, cooked and autoclaved forms. The crude protein of all raw legume seeds varied from 20.6 to 27.7%, crude fibre 3.2-9.5%, ether extract 1.3-6.7% and ash 3.0-4.8%. Potassium was the most abundant mineral, ranging from 9.9 g/kg in jack bean to 16.4 g/kg in lima bean TPL 88. Phosphorus was also appreciably high while sodium concentration was low. Iron contents were highest in kidney beans. The amino acid profile of the protein showed a consistent deficiency of methionine + cystine. Tryptophan was also limiting in pigeon peas while bambara groundnuts were borderline with regards to threonine. The lysine content of kidney bean pondo-6 was notably high compared with others. Cooked legume seeds contained relatively lower amounts of nutrient constituents assayed. The implications of these findings are fully discussed.