Utilization of Orange Flesh Sweet Potato and Chickpea Flour to Improve the Nutrient Content of Wheat Based Bread

Abstract

Bread is a worldwide staple food that is crucial for food security in Ethiopia. The country faces significant public health issues such as protein malnutrition and vitamin A deficiency. Nonetheless, there is a limitation of raw materials, wheat flour due to imported raw material. Therefore, it is essential to supplement wheat flour with locally available raw materials to improve the nutritional value of bread. Therefore, the study aims to investigate the possibility of blending chickpea and OFSP flour with wheat for preparation of bread. The experiment was conducted with two factors: flour blending ratio and bread baking temperature. A full factorial design was used to conduct the experiment and the analysis of the data was done using a statistical software package version 9.4. The flour blending ratio of wheat, chickpea and OFSP were 80:10:10, 70:15:15, 60:20:20, 50:20:30 respectively and control sample 100% wheat flour. The baking temperatures were 180, 200 and 220°C. The results of proximate composition of bread displayed that partial replacing wheat with chickpea and orange fleshed sweet potato increased the moisture content 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 but reduced carbohydrate 57.66 to 51.81%, and energy 281.64 to 257.10 Kcal/100, due to wheat flour high source of carbohydrate and energy. On the contrary, loaf weight of bread was 123.28 to 131.29 g increased due to higher water absorption capacity of both chickpea and OFSP flour than wheat while loaf volume 359.17 to 205.83 cm3 and specific volume of bread 2.91to 1.58 cm3/g were reduced due to reduction of gluten content present in wheat flour. With the rise in the proportion of chickpea and OFSP flour, the sensory acceptability of composite bread recorded in a scale 7 point were decreased from 6.19 to 2.77 in color, from 5.78 to 2.62 in texture, from 5.70 to 2.44 in flavor and from 5.90 to 2.58 in overall acceptability of bread. In conclusion, blending wheat with both chickpea and OFSP flour in bread formulations is found to be promising to improve the nutritional quality, especially protein and beta carotene contents of bread. In addition, giving attention to those locally under-utilized raw materials