Abstract
The evaluation of the chemical (proximate composition, mineral composition, toxicant composition and vitamin composition), nutritional and industrial potentials of two varieties of cocoyam (Xanthosoma sagittifolium (XS) and Colocasia esculenta (CE) were carried out using recommended methods of analysis. Baking trials were conducted with the two varieties of cocoyam at different levels of substitution (20%, 30% and 50%). The produced bread samples were analyzed for their physical parameters and proximate composition. Sensory evaluation test was also carried out on the produced bread. The result of the analysis showed that the preferred bread in terms of loaf weight, volume and specific volume was given by sample I (control sample) containing 100% wheat flour with a specific volume of 3.54 cm3/g. This was closely followed by sample A with specific volume of 3.25 cm3/g containing 20% substitution level of CE. Sample H containing 50% substitution level of XS with specific volume of 2.58 cm3/g gave the poorest performance. The sensory evaluation result further revealed that apart from the 100% wheat flour based sample I, sample D with 20% substitution level of XS was rated good and maintained better performance amongst the cocoyam varieties while samples G and C with 100% and 50% substitution level of CE respectively were rated the poorest. The proximate composition of the bread samples was also carried out. CE, XS and wheat bread samples (100%) recorded 15.0633±1.4531, 12.1133±1.5975 and 11.2867±0.7978 respectively for the moisture content. XS bread recorded the highest carbohydrate content of 45.0133±3.0274. In terms of ash, CE bread recorded the highest value of 31.4367±1.6159 while wheat bread recorded the highest value for protein i.e. 20.6033± 0.8113. XS performed better in terms of crude fat and energy value of 12.2967± 0.8914 and 371.5367 respectively. The use of cocoyam - wheat flour mixture in producing composite bread is therefore strongly recommended from this study.