Evaluating the proximate chemical composition and sensory properties of composite bread from wheat and cocoyam flours

Abstract

The proximate chemical composition and organoleptic properties of composite bread formulated from cocoyam-wheat mix were determined. A control (AWB) consisting of 100% wheat flour was used, and cocoyam-composite loaves of bread (CBA, CBB, CBC and CBD) were prepared at 5, 15, 25 and 35% levels of substitution of wheat flour with cocoyam flour, respectively. The proximate compositions were determined using the AACC, while sensory characteristics were carried out using the 9-point hedonic scale. The moisture content, crude protein, ash, energy value, fat, fibre and carbohydrate values of the composite bread were in the range of 10.89 - 17.16%, 8.78 - 11.58%, 6.35 - 6.89%, 409.80 - 430.40 (cal/100g), 7.43 - 11.62%, 0.36 - 0.57%, and 71.37 - 75.76%, respectively. Only, the CBD samples had a moisture content (10.89%) significantly different (p<0.05) from the control (14.57%). Low crude fibre values were obtained for all samples. Composite sample protein content levels were low, resulting from low protein levels in cocoyam. Ash values were generally higher and significantly different (p<0.05) from those of the control. Sensory evaluation showed that there was a decreasing trend in likeness for all sensory parameters from CBA to CBD, and no significant (p>0.05) difference was observed in texture, taste and aroma between the control and CBA samples (p<0.05). However, the colour, appearance, mouthfeel and acceptability showed a significant difference (p<0.05) between the 100% wheat and composite bread samples. These findings demonstrated that a 15% cocoyam flour substitution level in bread making produced acceptable bread samples to consumers with similar texture and aroma comparable to that of 100% wheat bread.   Key words: Cocoyam flour; bread; sensory evaluation; proximate composition.