Chemical Composition and Antioxidant Capacity of Some Selected Underutilised Bean Seeds Varieties

The effect of climate change on plant biodiversity, thereby affecting the number of such plant foods varieties for use in solving food insecurity cannot be overemphasized. Four varieties of cooked underutilised bean seeds (Cajanus cajan, Sphenostylis stenocarpa, Phaseolus lunatus 1, and Phaseolus lunatus 2) which are rarely consumed were evaluated for proximate and mineral compositions using standard analytical methods. Antioxidant activity and total phenolic content of the aqueous extracts of the seed flours were determined using Ferric-ion Reducing Antioxidant Potential (FRAP) assay and Folin Coicalteu method respectively. Percentage moisture of the samples ranged from 9.24 – 9.96; crude protein 20.79 – 22.72; fat 5.19 – 5.65; crude fibre 3.26 – 7.91; ash 3.37 – 5.94; with high metabolisable energy. Essential minerals such as K, Ca, and P were present at significantly high levels (p < 0.01) while the Na-K and Ca-P ratios for the samples were less than 1 indicating their suitability as diets for diabetic patients and food formulation for bone formation in children. Antioxidant activity of the samples ranged from 424.0 – 1295.7 mgGAE/100g while the total phenolic content ranged from 2740 – 5400 micromole GAE/g suggesting that the consumption of the bean seeds can be utilized as scavengers of free radicals produced by environmental pollution and essential body metabolic reactions. It is hoped that the inclusion of these underutilized bean seeds varieties in the diet will be a relief to the burden placed by the adverse effect of seasonal climatic changes on agriculture, thereby increasing food security.