Color, nutritional, and functional properties of six underutilized legumes

In this study, the color, nutritional and functional properties of six underutilized legumes were evaluated as a comparative screening exercise for potential food and protein ingredient applications. Nutritional analysis revealed high protein (18.45%–25.65%) and carbohydrate (58.53%–65.80%) contents, with low fat levels (1.50%–3.10%), ideal for protein extraction. Amino acid profiling showed appreciable levels of lysine, leucine, phenylalanine, and abundant glutamic and aspartic acids . In vitro protein digestibility ranged from 78.60% to 92.01%, with climbing bean (CB) showing both the lowest digestibility and the darkest flour color. Functional property analyses demonstrated relatively high-water absorption capacities (1.00–1.8 mL/g), strong emulsifying capacity (>80%), excellent foaming ability (>100%), although foaming stability remained limited (<20%) across samples. Least gelation concentration varied among flours, with CB and dwarf French bean (DB) forming gels at lower concentrations of 8 and 10% (w/v), respectively. Among the legumes evaluated, broad bean (BB) showed a favourable balance of protein content, in vitro digestibility, and functional properties, supporting its candidacy for further investigation as a protein source. Overall, this study provides the color, nutritional and functional assessment of these underutilized legumes, highlighting their potential as sustainable plant protein sources and identifying targets for antinutrient reduction and functional optimization.