Effect of Processing on in–vitro Protein Digestibility and Anti–nutritional Properties of Three Underutilized Legumes Grown in Nigeria

Comparative studies are conducted on the effect of roasting and boiling methods on anti–nutritional properties and in–vitro protein digestibility of bambara groundnut (Vigna subterranea L.), scarlet runner bean (Phaseolus coccineus L.) and lima bean (Phaseolus lunatus L.) which are legume seeds grown in Nigeria. For this purpose some anti–nutritional factors and in–vitro protein digestibility were investigated using standard analytical techniques. Roasting method significantly reduced the anti–nutritional contents while in–vitro protein digestibility values were also decreased by 35.54%, 60.36% and 53.32% for Vigna subterranean, Phaseolus coccineus and Phaseolus lunatus, respectively. Boiling on the other hand significantly decreased the anti–nutritional properties as well as improved the in–vitro protein digestibility by 17.77%, 15.09% and 35.54% for Vigna subterranean, Phaseolus coccineus and Phaseolus lunatus, respectively. Among the two domestic processing methods, boiling was the most effective in reducing anti–nutritional factors and improving in–vitro protein digestibility.