Chemical Composition, Pasting and Functional Properties of Sorghum bicolor, Phaseolus lunatus and Xanthosoma sagittifolium Flour Blends for Complementary Food Production

Abstract

Aim: The work aimed at producing composite flour from blends of sorghum, lima beans and cocoyam flour to address micro and macronutrient deficiencies, improve functional properties and as value addition to the utilization of local crops. Methodology: Composite flour was produced from sorghum (Sorghum bicolor), lima bean (Phaseolus lunatus) and cocoyam (Xanthosoma sagittifolium) flour blends at different ratios; 100:0:0:0 (control), 0:80:15:5, 0:70:20:10, 0:60:25:15, 0:50:30:20 and 0:40:35:25 respectively. Each blend was evaluated for proximate, mineral compositions, functional and pasting properties. Results: The proximate results showed that the protein content for all flour blends ranged from 7.26-10.75%. SLC1 and SLC3 had significant (p<0.05) higher protein content than the control sample (9.65%). The FAO/WHO minimum required protein level of 10% was only met by these two flour blends. Due to their low moisture content (10.13–10.94%), all the flour blends might have a longer shelf life and maximum storage capacity as compared to the control (11.51%). The sodium (45.1-52.4 g/100g) and calcium (88.4-103.5 g/100g) contents of the flour blends are significantly (p<0.05) higher than that of the control (2.4 and 40.8 g/100g). The oil absorption capacity (OAC) increased significantly (p<0.05) from 8.03 to 9.39 g/ml with the highest OAC from sample SLC3 (9.39 g/ml). The OAC of flour is important as it improved the mouth feel and retains the flavour. There was improved pasting properties with composite flours compare to 100% wheat flour. Sample SLC2 (50% sorghum, 30% lima bean, 20% cocoyam) had the highest peak, trough, setback and final viscosity indicating better thickening, heat stability, and gelling potential. The SLC2 formulation (50% sorghum, 30% lima bean, 20% cocoyam) consistently exhibited superior pasting characteristics Conclusion: That composite flour blends have demonstrated better potential in replacing wheat flour for baking applications.