Response surface optimization, nutritional, and sensory evaluation of bread developed from wheat, amaranth, and banana composite flour

Protein malnutrition is a major health problem that mainly affects vulnerable groups such as children in many developing countries, including Ethiopia. Bread is a staple food in Ethiopia and many other countries. The production of banana fruit and amaranth grain is high in the southern part of Ethiopia. This project aimed to develop bread from wheat, banana, and amaranth grain flour and to formulate an optimum blend with those flours to obtain a highly nutritious bread. Banana and amaranth flour were prepared using standard methods. Response Surface Methodology was conducted using an optimal (combined) design to determine the best blend ratio of wheat, banana, and amaranth flour. The design was based on the lower and upper proportions of wheat (50–100%), amaranth (0–30%) & banana (0–20%) flour. The sensory value was analyzed using a seven-point hedonic scale. Composite flour bread was developed based on the design output. The optimum composition of wheat, banana, and amaranth flour was 52.71%, 18.45%, and 28.84%, respectively. The proximate compositions, such as moisture, ash, crude fiber, crude fat, and crude protein of optimized bread contained 30.59%, 2.42%, 6.41%, 3.20%, and 12.66% respectively. The carbohydrate and caloric value were 44.72% and 258.32 kcal was recorded respectively. Whereas antinutritional content (tannin and phytate) of optimized bread was obtained as 1.26 and 2.06 mg/100 g, respectively. Based on the result calcium and zinc content of composite flour bread were 75.87 and 3.54 mg/100 g, respectively. The sensory evaluation of the optimized bread showed significant improvement in texture (6.35 vs. 5.76), while color scores slightly decreased (5.54 vs. 6.73) compared to the control bread. The results were analyzed using ANOVA at LSD < 0.05 with Minitab version 19 software. Therefore, bread from wheat, banana, and amaranth offers a nutritionally enhanced, locally adaptable, and sustainable food product that can contribute to combating protein malnutrition, hidden hunger, or micronutrient deficiencies, improving food security, and supporting public health.