Nutritional and functional potentials of wheat, cowpea, and yam composite flours on bread formulations: Effect of blending ratio and baking parameters

Bread, a staple food, primarily utilizes wheat as the main ingredient due to its high carbohydrate content, despite being considered nutritionally deficient. In the present study, wheat flour was substituted with cowpea and yam flours. The raw materials were processed into flour, and the proximate composition, functional properties, and anti-nutritional contents of the individual and blend flours (B₁ = 85 % wheat + 5 % cowpea +10 % yam, B₂ = 70 % wheat + 10 % cowpea +20 % yam, and B₃ = 55 % wheat + 15 % cowpea +30 % yam) were analyzed. The main findings revealed that the incorporation of cowpea and yam flours led to significant increases (p < 0.05) in the total ash content, crude protein content, crude fiber content, bulk density, water absorption capacity, oil absorption capacity, swelling power, phytic acid content, tannin content, and oxalate content. Additionally, the effects of the blending ratio, baking temperature (180–220 °C) and baking time (25–35 min) on the bread formulation were investigated using response surface methodology (RSM). As the blending ratio progressed from B₁ to B₃, a noticeable decrease in both the specific volume and sensory attributes of the bread were observed. Similarly, with an increase in baking temperature and duration, the bread exhibited a decline in its crude protein and crude fiber contents. Breads formulated with up to 10 % cowpea flour and 20 % yam flour, baked at higher temperatures and times, received greater overall acceptability from panelists. These findings suggest that substituting bread wheat flour with cowpea and yam flours is an innovative approach for developing nutritious and appealing bread products.