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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
*Corresponding author. E-mail: ola4ade@yahoo.com.
Tel.: + 2348030758356, +2348076154599.
Accepted
4 June, 2008 |
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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 m2 for 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. |
