Proximate composition, bread characteristics and sensory evaluation of cocoyam-wheat composite breads

Abstract

This study was carried out to investigate proximate composition, bread characteristics and sensory evaluation of cocoyam-wheat composite breads at different levels of cocoyam flour substitution for human consumption.A whole wheat bread (WWB) and cocoyam-composite breads (CCB1,CCB 2 and CCB 3) were prepared in triplicate at 0, 10, 20 and 30% levels of cocoyam flours substitution respectively and assessed for proximate composition, bread characteristics and sensory attributes.The results indicate that carbohydrate, crude fiber, and ash contents of the cocoyam- composite reads increased significantly (p<0.05) while the moisture and protein contents decreased significantly with progressive increase in the cocoyam flour substitution. The significant (p<0.05) highest ash, fibre and carbohydrate values of 1.61, 1.54 and 70.40 g/100g dm respectively were observed in 30% cocoyam-wheat composite bread compared to lowest values of1.15, 0.29 and 63.25 g/100g dm, respectively in 100% wheat bread. The significant (p<0.05) higher moisture and protein values of 20.99 and 12.54 g/100g dm were observed in 100% wheat bread compared to lowest values of 17.31 and 9.04 g/100g dm, respectively in 30% cocoyam-wheat composite bread. Bread characteristics showed that, the loaf weight of cocoyam composite breads increased significantly (p<0.05) while loaf volume and specific loaf volume decreased significantly (p<0.05) with increasing cocoyam flour substitution The significant (p<0.05) highest loaf weight of 229.33 g was observed in 30% cocoyam-wheat composite bread compared to 208.33, 221.67 and 225 g observed in 100% wheat bread, 10 and 20% cocoyam-wheat composite breads respectively. The highest loaf volume and specific loaf volume of 800 and 3.49 cc were observed in 100% wheat bread compared lowest values of 580 and 2.78 cc respectively observed in 30% cocoyam-wheat  composite bread. The sensory evaluation showed no significant (p>0.05) differences in sensory attributes of taste, aroma and acceptability between the 100% wheat and 10% cocoyam-wheat composite breads (p<0.05). In conclusion, this study has shown that the use of cocoyam flour in bread making is feasible and that incorporation of up to 10% of the flour into wheat flour produced acceptable bread with similar taste and aroma comparable to 100% wheat bread. Nevertheless, it is important to consume this bread with other protein rich diet in order to supplement the reduction resulted from substitution.