S.D. OYEYEMI, M.J. AYENI AND A.J. ADESINA
Abstract
Abstractââ¬âNutritional profile, mineral content as well as mineral ratio, mineral safety index and antinutrient content of locally grown fabaceae species (Cajanus cajan, Sphenosytlis sternocarpa, Phaseolus lunatus and Vigna unguiculata) were investigated. The bioavailability of the minerals was predicted using antinutrient-mineral molar ratios. The proximate analyses of the beans showed that the moisture content, crude protein, crude fat, ash, crude fiber and carbohydrate ranged as followed: 8.76-9.62%, 14.85-17.55%, 2.48-3.28%, 2.48-2.71%, 2.87-3.59% and 64.76-67.21% respectively. The total energy from carbohydrate, fat and protein was high and close at 1499-1515kJ/100g and low CV% of 0.47-0.48 being mostly contributed by carbohydrate (73.12-75.42%) and followed by protein (16.66-19.82%). Utilization of 60% of energy due to protein was low at 9.99-11.89 at CV% 7.23. The mineral levels (g/100mg) were high in K (33.2-44.4) and P (92.0-128) moderate in Ca (14.5-19.4), Mg (8.14-14.5) and Fe (6.00-13.97) but low in Zn and Cu and very low in Mn, Pb, Cd and Ni. The mineral CV% ranged from low to high (7.44-47181) with no significant difference at P=0.05. The result of the mineral ratio revealed that the calculated mineral ratios for Na/K, K/Na, Ca/P, Ca/Mg, Ca/K, Zn/Cu and [K/(Ca+Mg)] were good when compared with the standard. All calculated mineral safety index were lower than the tabulated values indicated no mineral overload to the consumer. The low anti-nutrient concentrations (mg/100g) of phytate (1.51-2.61) and hydrocyanide (7.49-12.52) could make them ranked among the bean species safe for human consumption while the antinutrient-mineral molar ratios depicted phytate to mineral ratios of all the beans falls below the critical values, no significant difference at P=0.05 among the ratios. This indicated that the bioavailability of Ca, Fe and Zn is not affected by their phytic acid contents. The bean seeds might prove to be a good source of carbohydrate, crude protein, minerals and gross energy values. The anti-nutrient, mineral safety and phytate to mineral ratio were found to be within the acceptable level suggested that the foods are suitable for human and animal consumption.