African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12191

Full Length Research Paper

Some thermo-physical properties of yam cuts of two geometries

M. O. Oke1*, S. O. Awonorin2, O. J. Oyelade3, J. O. Olajide1, G. O. Olaniyan1 and P. O. Sobukola2
  1Department of Food Science and Engineering, LAUTECH, Nigeria. 2Department of Food Science and Technology, UNAAB, Nigeria 3Procter Department of Food Science, University of Leeds, Leeds LS2 9JT, UK    
Email: [email protected]

  •  Accepted: 04 June 2008
  •  Published: 06 April 2009

Abstract

 

 

The effects of variation of temperature (-18 to 33°C) and geometries (slab and cylinder) on some thermo-physical properties of white yam were investigated. The measured parameters were density, specific heat, and thermal diffusivity at constant moisture level of 72.7% ± 0.69 (wet basis) using transient heat transfer method. Both the density and specific heat of the sample increased with increase in temperature to maximum levels after which further increase led to a reduction of the values of these parameters; however, they were independent of sample’s geometry. The rate of heat diffusion per second for the yam as measured was between 2.365 to 11.86 x 10-8 m2 and 2.676 to 8.062 x 10-8 mfor slab and cylinder respectively. The thermal diffusivity and computed thermal conductivity were found to increase with increase in temperature. Conclusively, these thermo-physical properties were correlated with temperature using polynomials of the third order empirical model.

 

 

 

 

 

 

 

 

 

 

Key words: Thermo-physical Properties, density, specific heat, thermal conductivity thermal diffusivity and Yam.