ABSTRACT

The objectives of this research were to evaluate the chemical composition and sensory evaluation of sorghum flour (SF) and bambara groundnut flour (BF) on the quality of wheat bread. Bambara groundnut and Sorghum seeds were processed into flour and mixed with wheat flour in the ratio of 5:15:80, 5:20:75 and 25:25:50 for bread production. The breads were prepared by the straight dough method. Four samples of bread were produced and denoted as Sample G, H, I and J respectively. Sample G served as control with 100% wheat flour, while Sample H to J consists of composite wheat-sorghum-bambara groundnut flours in ratio of 80:15:5, 75:20:5 and 50:25:25% respectively. Analysis such as functional and chemical evaluation of flour blends were carried out to determine its suitability for bread and other confectioneries. Chemical composition, sensory properties and physical characteristics such as weight, volume and specific volume were evaluated. The result of the proximate composition showed that carbohydrate content decreased significantly (p<0.05) with increase in sorghum and bambara groundnut flour blends varying from 79.52.16 to 74.07%. The moisture, protein, ash, crude fibre and fat contents of the bread samples generally increased significantly (p˃0.05) with increase in sorghum and bambara groundnut flours. Sorghum flour only showed significantly (p<0.05) higher water holding capacity than wheat flour and bambara groundnut flour blends respectively. The physical properties of the bread loaves were evaluated. The loaf volume of composite breads decreased significantly (p<0.05) from 260.0 to 1.44cm³. Samples H to J showed a significant increase (p<0.05) in weight and specific volumes of the bread samples of 293.5-312.5g and 0.08-0.70cm³/g respectively. The mineral (Mg and P) contents of the bread samples decreased significantly (p<0.05) with increased percentages of Sorghum flour and Bambara groundnut flour in the bread.  The result of the sensory properties showed that there was significant (p<0.05) difference in the taste, flavor, crumb colour and overall acceptability of the 100% wheat bread and from composite samples. The 100% wheat bread recorded the highest scores in all the parameters evaluated. However, all other samples were well accepted. Sample J showed a decrease in the values of taste, flavor and overall acceptability of the bread samples with increasing levels of sorghum and bambara groundnut flour.