Comparison of Selected Engineering Properties of Two Species of Cocoyam Essential for Handling of the Tubers

Abstract

ABSTRACT

Production of cocoyam is mainly carried out manually. Adequate knowledge of their engineering properties is a prerequisite for the development of machinery for harvesting and processing of cocoyam. Some engineering properties of cocoyam from two species of cocoyams, namely Colocasia exculenta (taro) and Xanthosoma saggittifoluim (tannia) were compared. The properties investigated include tuber length, width, volume, angle of repose, density, static coefficient of friction, force–deformation behaviour during compression, stiffness moduli and

tuber toughness. Xanthosoma sagittifolium was found to have length of 9.66 ± 4.65 cm, width of 4.24 ± 0.55 cm, and thickness of 4.20 ± 0.73 cm; while Colacassia esculenta have length of 8.5 ± 3.30 cm, width 3.52 ± 0.33 cm and thickness of 3.51 ± 0.34 cm. Xanthosoma sagittifolium and Colacassia esculenta was found to have an average moisture content of 57.65 % and 58.91 % (wet basis)respectively. The average mass, volume and density of Xanthosoma sagittifolium are 126.28 g, 123.75 cm3 and 1.02 g/cm3 respectively while the mass, volume and density of Colacassia esculenta are 76.21 g, 75.42 cm3 and 1.01 g/cm3 respectively. The mean values of coefficient of static friction was 0.31and 0.21 on wood, 0.31and 0.21 on glass, 0.22 and 0.20 on stainless and 0.25 and 0.21 on galvanized iron surfaces for Xanthosoma sagittifolium and Colacassia esculenta respectively. The average values of angle of repose of Xanthosoma sagittifolium and Colacassia esculenta were 14.05 and 11.99; compressive force was 1628.68 N and 1121.08 N; toughness of 11.02 Nm and 6.89 Nm; Young Modulus of 2365.0 N/mm2 and 11.98 N/mm2 respectively.

 

Keywords: Cocoyam, Physical properties, Mechanical properties, Mean, Density, Force.