Bread is a widely consumed staple, yet conventional formulations are often limited in protein density, fiber, and mineral content, making fortification a valuable strategy for improving household nutrition. This study aimed to evaluate the nutritional, sensory, physicochemical, and economic impacts of incorporating soya protein isolate (SPI) and fonio flour into home-based bread production. The objective was to determine whether low-to-moderate substitutions of these ingredients could enhance nutritional quality without compromising sensory acceptance or affordability.

Materials and methods involved preparing composite flour blends by substituting wheat flour with SPI at 2%, 4%, and 6% levels, fonio flour at 2%, 5%, and 8% levels, and combined SPI-fonio blends (2%+2% and 4%+5%). Breads were produced using the straight-dough method and assessed through proximate analysis (protein, fiber, ash, moisture, carbohydrate), physicochemical evaluation (loaf volume, crumb firmness, crust color), sensory evaluation by a 25-member semi-trained panel using a 9-point hedonic scale, and economic assessment of ingredient costs. Statistical analysis employed ANOVA and Tukey’s HSD to identify significant differences (p < 0.05).

Results indicated that protein content increased significantly with SPI substitution, while fonio contributed fiber and minerals. Optimal ranges of 2-4% SPI and 2-5% fonio produced nutritionally superior loaves with acceptable loaf volume, crumb softness, and sensory scores. Higher substitution levels (>4% SPI and >5% fonio) resulted in firmer crumbs, reduced loaf volume, and lower acceptability scores. Combined substitutions (SF2+2) maintained quality close to the control while offering enhanced nutrition. Economic analysis showed incremental costs of 6-9% for optimal blends, remaining within consumer willingness-to-pay thresholds.

In conclusion, moderate fortification of bread with SPI and fonio is nutritionally beneficial, sensorially acceptable, and economically feasible for households. This approach provides a practical pathway for improving everyday diets through simple modifications in home bread-making practices.