Some physicochemical properties and anti-nutritional factors of raw, cooked and germinated Jack bean (Canavalia ensiformis)

Physicochemical properties and anti-nutritional factors of raw, cooked and germinated Jack bean (Canavalia ensiformis) were studied. Jack bean seeds were relatively large, measuring 1.88 cm in length, 1.32 cm in width and 1.09 cm in thickness. The 1000 seed weight was 1.78 kg. The seed coat formed about 13.3% of the whole seed, resulting in high fibre content of the meal. The Jack bean was high in protein (23.3%) and starch (24.7%). Hydrogen cyanide and phytate levels in the raw beans were 11.2 mg/100 g and 2.78 g/100 g dry sample, respectively. Haemagglutinin and trypsin inhibitor activities were detected in the bean. Cooking and germination had varied effects on bean constituents. Raw bean flour had a fairly good foam capacity which was reduced considerably by cooking and germination. The Brabender amylograph showed that the bean starch had poor cooked paste properties and this may, in part, explain why the bean is difficult to cook.