Elasticity of cocoyam cormel as influenced by moisture content and loading orientation

Abstract

Cocoyam, Xanthosoma sagittifolium, is one of the major staple food items in Nigeria. The crop is recently gaining attention and there is urgent need to intensify research efforts towards fully exploiting its promising potentials. Information on the elastic properties of the cocoyam cormels are necessary for understanding of their behaviour under loading and in the design of equipment for proper handling of the cormels during processing and storage. This study investigated the elasticity of cocoyam cormels as affected by moisture content and orientation of loading. White-fleshed and pink-fleshed varieties of the X. sagittifolium cormels were used for this study. The elastic properties of the cormels along the three mutually-perpendicular axes were determined. Deformation at rupture, modulus of elasticity (MOE), degree of elasticity (DOE) after first and third cycles along the longitudinal, cross-sectional and transversal directions ranged between 5.14 and 11.64 mm, 3.03 and 11.70 Nmm-2, 0.51 and 0.73 mm, 0.45 and 0.70 mm, respectively. The degrees of elasticity of the cormels decreased with increasing number of loading and unloading cycles thereby, limiting the stack height of cocoyam cormels in transit and storage to reduce mechanical damage and subsequent postharvest losses. The study provides information that can serve as guide in ensuring proper handling of cocoyam cormels in transit and storage.