Epsilon Archive for Student Projects

Abstract

Increasing costs for wheat imports due to higher demand for wheat-based food products in many tropical developing countries such as Ghana has led to an interest in cassava flour as partial substitute for wheat flour in bakery products. The aim of this study was to characterize physico-chemical properties of cassava flour compared to wheat flour and determine its maximum acceptable substitution level in composite wheat/cassava bread and cakes in terms of baking and organoleptical characteristics. Flours from three different local varieties of cassava (Afisiafi, Bankye hemmaa and Doku Duade) were compared. Cassava roots were processed into flour by grating, sun-drying and milling. Quality parameters such as moisture and starch content and acidity as well as functional properties in water such as pasting characteristics, swelling power and water-binding capacity were determined. Breads and cakes including 10, 20 and 30 % cassava flour were baked and evaluated for specific volume, density and hardness. The products were submitted to a semi-trained panel of Ghanaian urban consumers for sensory analysis. Flour yield from processing of three varieties of cassava roots into flour ranged from 18 to 19.9 %. Swelling power ranged from 10.5 to 12, swelling volume from 8.6 ml to 11 ml, solubility from 11 % to 20.8 % and water-binding capacity from 152 % to 166.9 %, higher values than for wheat flour. This could be explained by a higher starch content in cassava flour that ranged from 87.8 to 89.2% on dry matter basis. Cassava flours were characterized by an early gelatinization (pasting temperature between 70 and 71°C), high peak viscosity, large paste breakdown and low retrogradation tendency compared to wheat flour. As the substitution level increased in wheat/cassava bread, loaf specific volume decreased and density and hardness increased. Breads baked with 10% and 20% cassava flour were accepted by the sensory panel in terms of appearance, taste and texture and up to 30% was accepted in cakes. These results showed that High Quality Cassava Flour has potential to replace part of the wheat flour in bakery products since there is a wide acceptance among consumers.