Effect of Bambara Groundnut Flour (Vigna subterranea) Inclusion on the Functional, Pasting, Physical and Proximate Properties of Composite Cassava-bambara Flour

Abstract

This study evaluated the effect of Bambara groundnut flour inclusion on the functional, pasting, physical properties and proximate compositions of composite flour (CF) from cassava and Bambara groundnut. Cassava variety (IITA-TMS-IBA011368) and Bambara groundnut were processed into flour and blended together based on D-Optimal mixture design with an outcome of eight experimental samples using Design Expert Software (Version 12.0). The flour blends were analyzed for functional, pasting, physical properties (color), baking strength and proximate composition. Data obtained were analyzed using analysis of variance and means were separated using Ducan’s Multiple Range Test. Range of results for bulk density, water absorption capacity, swelling index, solubility index and oil absorption capacity of the composite flour are 0.64-0.80g/mL, 0.38-1.37%, 0.77-0.91%, 6.00-8.65, 1.58-2.97, respectively. The peak viscosity, trough, breakdown viscosity, final viscosity, setback viscosity, peak time and pasting temperature ranged from 162.84±2.09 to 426.50±1.83 RVU, 77.96±2.71 to 195.59±8.91 RVU, 84.88±0.63 to 234.75±5.58 RVU, 158.92±4.34 to 293.17±1.34 RVU, 76.88±18.04 to 101.42±5.08 RVU, 4.10±0.03 to 5.93±0.00 min and 75.05±0.05 to 94.78±0.38 oC, respectively. The baking strength characteristics of the flour blends such as moisture, ash, color, wet gluten, zenleny dry protein and wet protein ranged from 11.55 to 12.55%, 0.50 to 1.25%, 88.65 to 90.55, 8.35 to 13.80, -2.35 to 41.25, 4.92 to 13.85% and 4.53 to 11.99 %, respectively. Moisture, ash, fibre, fat, protein and carbohydrate of the composite flour ranged from 7.57 to 11.87%, 0.42 to 2.40 %, 1.78 to 3.00%, 2.81 to 5.62%, 8.42 to 12.68% and 67.61 to75.99%, respectively. Flour lightness, redness and yellowness ranged from 33.22 to 54.10, -2.89 to-1.14, 5.94 to 9.35, respectively. The inclusion of Bambara groundnut flour had a significant effect on the functional (swelling index, water and oil absorption capacity), pasting (peak, trough and final viscosity) and proximate (ash, fat and carbohydrate) properties of the flour blends.