ABSTRACT

This study is aimed al. determining the engineering properties of cocoyam corms and cormels relevant in the mechanization of its production and processing. Three species of cocoyam (colocasia esculenta) were studied Edeofe (Nceoo2), Cocoindia (Nceool), Ukpong (Nceoo3). 16 physical properties of Edeofe and Cocoindia were determined as well as their mechanical properties. The experiment showed that the average weight and volume of Cocoindia corms were 185.98g and 80.00mm3respectively while the cormels had 74.50g and 150.00mm3respectively. Compared to Edeofe corms (102.67g, 110.00mm3) and cormels (40.88g, 80.00mm3) it was found that Cocoindia corms and cormels were higher in value. There was a slight decrease in the GMD and AMD of Edeofe corms when compared to that of Cocoindia corms but Cocoindia cormels had a higher mean value when compared to Edeofe cormels. Edeofe corms sphericity values ranged from 37.44dec to 111 .46dec with a mean sphericity of 66.55dec. Edeofe cormels in same order ranged from 18.63dec to 91.l2dec with a mean sphericity of 46.25dec. Coco india -corms had a lesser sphericity value when compared to edeofe corms with an average sphericity of 49.78dec ranging from 31 .38dec to I 02.33dec while that coco india cormels ranged from I 04.49dec with an average of 55.77dec which is higher when compared to edeofe cormels. Porosity values for edeofe corms ranged from -11.83% to 0.8% with an average of 0.01%. Edeofe cormels had an average porosity of 0.46% which ranged from -0.27% to 0.76%. values for coco india corms ranged from -1 .70% to 0.65% with an average of 0.26% with the cormels averaging 0.5 1 % at a range of-U. 11% to 0.83%. The Testometric material testing machine was used in determining the mechanical properties of the three cocoyam species. Edeofe cocoyam specie at compression load at break 303.5 ION, 354.34N and 283,290N gave a deformation of 5.039mm, 6.60mm and 8.556mm respectively when placed transversely while when placed longitudinally at compression load at break 227.7 IN. 234.09N and I 90.33N gave a deformation of9,2 17mm. 10.037mm and 10.296mm respectively. Ukpong and Cocoindia cocoyam species showed similar characteristics when placed transversely and longitudinally on the testing machine. The mechanical test generally, showed that gradual increase in compression load on the cocoyam leads to extension on its axis thereby causing a crack or break. This increases as more load is applied, thereby giving an upward slope in the graph which shows that increase in load leads to increase in extension of the cocoyam axis.