Effect od Soybean/Cassava Flour Blend in the Proximate Composition of Ethiopian Traditional Bread Prepared from Quality Protein Maize

Abstract

The effect of soybean and cassava flour blend on the proximate composition of Ethiopian traditional bread prepared from quality protein maize (QPM) was tested. Normal maize and quality protein maize grains were dried, cleaned and milled using a laboratory-scale mill. Similarly, soybean seeds were roasted, boiled, decorticated, and milled into the required particle size flour sample. Cassava tubers were also peeled, chopped, dried and milled in a similar fashion. Eventually, the soybean and cassava flour samples were blended individually with the quality protein maize flour in three different proportions: 5:95, 10:90 and 15:85, respectively. Normal maize flour was used as a control for the quality protein maize flour. Then bread samples were prepared from the respective composite flours using the sponge and dough method of bread making commonly used in the country. Both the composite flours and the respective bread samples were then analyzed for their proximate compositions: moisture, ash, crude protein, crude fat, crude fibre and carbohydrate. The proximate analyses indicated that there is a significant difference (p ≤ 0.05) in proximate composition of the plain quality protein maize bread (QPMB) and the soybean- or cassava-supplemented quality protein maize bread samples (SSBs and CSBs). The ash, crude protein, crude fat and crude fibre contents of the soybean-supplemented breads increased with progressive increase in the proportion of soybean flour addition. In the case of the cassava-supplemented bread samples, the highest proximate composition values were recorded for the 10% substitution. Moreover, highest values of carbohydrate, 39.83% and 44.08%, were obtained for the 10% soybean-supplemented breads and 10% cassava-supplemented breads, respectively. The use of these locally available and easily produced grains through blending technology of flours can contribute to combat the widespread protein-energy malnutrition (PEM) in Ethiopia. This approach can also serve as an alternative means for having balanced diet especially for the low-income groups of the most food-insecure people in the country.

Key words: Maize, soybean/cassava, bread, proximate composition