COMPRESSIVE STRENGTH PROPERTIES OF CASSAVA ROOTS AS AFFECTED BY MOISTURE CONTENT

Abstract

In Nigeria, recent transformation of cassava into an industrial raw material has made the need for mechanization of its postharvest processing operations imperative for sustainable rural development as a means of achieving Millennium Development Goals (MDGs). Processing technologies presently available for processing cassava roots have low efficiencies due to dearth of relevant data on the engineering properties of the root. This paper presents the studies on strength properties of cassava roots that are considered useful for the mechanization of cassava postharvest processing operations. Improved cassava variety (TMS 30572) roots harvested twelve months after planting was used in the study. The properties studied include stress at peak, energy to break and the Young’s modulus of the roots. The tests were conducted at moisture contents of 50, 55, 60, 65 and 70% (wet basis) using the Universal Testing Machine (UTM). Results obtained were analyzed to evaluate the strength, toughness and stiffness of cassava as well as the influence of moisture contents on these three parameters. The stress at peak, energy to break and the stiffness modulus ranged from 0.61 to
0.88 N/mm²; 4.80 to 6.67 Nm and 4.81 to 9.28N/mm² respectively within the range of moisture content studied. A non-linear relationship-3^rd order polynomial was observed between moisture content and the strength properties studied.