African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12275

Full Length Research Paper

Modelling the rheological properties of gruels produced from selected food products from Cameroon

Cybele Maka Taga
  • Cybele Maka Taga
  • Department of Chemical Engineering and Environment, University Institute of Technology (IUT) of the University of Ngaoundere, P. O. Box: 455 Ngaoundere, Cameroon.
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Yvette Jiokap Nono
  • Yvette Jiokap Nono
  • Department of Chemical Engineering and Environment, University Institute of Technology (IUT) of the University of Ngaoundere, P. O. Box: 455 Ngaoundere, Cameroon.
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  •  Received: 27 December 2016
  •  Accepted: 21 March 2017
  •  Published: 26 April 2017

Abstract

This study investigated the flow behaviour of some food gruels obtained from pre-treated banana, sorghum or sesame flours. The Herschel-Bulkley and the power law models were used to evaluate the consistency and flow indices while an Arrhenius-type equation was used to analyse the effect of temperature on viscosity. The Ostwald de Waele model gave a good fit with experimental data, with p-values less than 0.01 and R2 values greater than 0.96 for most of the experiments. The results revealed a pseudoplastic, dilatant and time independent character for the sorghum gruels while the sesame and banana gruels revealed a pseudoplastic and time-dependent character. The effect of temperature on viscosity led to an activation energy and second Arrhenius parameter varying from 964 to 21,070 J.mol-1 and from 81 to 34,484 Pa.s respectively. The concentration dependence of the consistency index was modelled using an exponential equation and showed a decrease with temperature.

 

Key words: Sorghum gruel, sesame gruel, banana gruel, power law, Arrhenius law, time dependency.