Enhancing Wheat Bread Nutrient Content with Orange Flesh Sweet Potato and Chickpea Flour

Background and Objective: Bread is vital for food security in Ethiopia, addressing protein malnutrition and vitamin A deficiency. However, the country is limited by its reliance on imported wheat. Therefore, it is essential to supplement wheat flour with locally available raw materials to improve the nutritional value of bread.Therefore, this study aims to investigates the blending ratio of chickpea and OFSP flour with wheat at different baking temperatures to prepare nutritionally enhanced and high-quality bread. Materials and Methods: The experiment was conducted in a full factorial design with two factors: Flour blending ratio (80:10:10, 70:15:15, 60:20:20, 50:20:30 for wheat, chickpea and OFSP, respectively and a control of 100% wheat flour) and baking temperatures (180, 200 and 220°C).The study analyzed the proximate composition of flour and bread, including moisture, ash, protein, fat, fiber, carbohydrates and β-carotene, while also evaluating the bread’s physical and organoleptic properties. Data analysis was conducted using SAS software package version 9.4. Results: The proximate composition of bread showed that substituting wheat with chickpea and orange-fleshed sweet potato increased moisture (28.84 to 35.79%), protein (10.85 to 14.59%), fat (0.85 to 2.05%), fiber (1.49 to 1.84%), ash (0.93 to 2.06%) and β-carotene (0 to 8.04 μg/g of bread). However, it decreased carbohydrate (57.66 to 51.81%) and energy content (281.64 to 257.10 kcal/100 g), due to wheat flour high source of carbohydrate and energy. On the contrary, bread loaf weight increased (123.28 to 131.29 g) due to the superior water absorption capacity of chickpea and OFSP flours compared to wheat. However, loaf volume (359.17 to 205.83 cm³) and specific volume (2.91 to 1.58 cm³/g) decreased due to reduced gluten content in wheat flour. As the proportion of chickpea and OFSP flour increased, sensory acceptability ratings on a 7-point scale decreased: Color (6.19 to 2.77), texture (5.78 to 2.62), flavor (5.70 to 2.44) and overall acceptability (5.90 to 2.58) of the bread. Conclusion: Blending wheat with chickpea and OFSP flour in bread formulations is promising to improve the nutritional quality, especially protein and beta carotene contents of bread. Furthermore, giving attention to the locally underutilized raw materials is an alternative for the growing population.