Publication no. C-2002-0805-07R |  VIEW ARTICLE

Mathematical Modeling of Odor Deterioration of Millet (Pennisetum glaucum) Dough (fura) as Affected by Time-Temperature and Product Packaging Parameters.

V. A. Jideani (1,2), I. Nkama (3), E. B. Agbo (4), and I. A. Jideani (4). (1) Department of Food Science and Technology, Federal Polytechnic, P.M.B. 0231, Bauchi, Nigeria. (2) Corresponding author. E-mail: <vjideani@yahoo.com> (3) Department of Food Science and Technology, University of Maiduguri, P.M.B. 1069, Maiduguri, Nigeria. (4) Biological Sciences Programme, Abubakar Tafawa Balewa University, P.M.B. 0248, Bauchi, Nigeria. Cereal Chem. 79(5):710-714. Accepted February 18, 2002. Copyright 2002 American Association of Cereal Chemists, Inc.

Consumer panelists evaluated the influence of temperature (5, 25, 35°C), storage time, and packaging material (aluminum foil or low-density polyethylene [LDPE]) on the sensory quality of millet dough (fura). The quality attributes of interest were mold growth, color, odor, and moisture. The odor sensory attribute changed significantly (P < 0.05) during storage and was influenced by storage time and temperature. Interactive effect of packaging-temperature and temperature-time affected odor changes significantly. A kinetic reaction model was used to analyze odor sensory data. The degradation of pleasant odor followed a first-order reaction, and the temperature dependence of these reactions indicated an Arrhenius relationship. While an activation energy (E(A)) of 29.98 kJ/mol was calculated for samples stored in aluminum foil, a higher value of 49.04 kJ/mol was obtained for samples stored in LDPE. The negative values of enthalpy (DeltaH*) in both packages indicate that deterioration change in fura is exothermic. The higher values of E(A) and free energy of activation (DeltaG*) for fura stored in LDPE packages indicate a large change in quality. However, the lower values of free energy of activation (DeltaG*) and negative values of entropy of activation (DeltaS*) for fura stored in aluminum foil packages indicate a product that is more thermally stable, and odor deterioration is less influenced by temperature. There is no significant difference (P > 0.05) in the shelf life of fura stored at 20, 25, and 35°C in the two packaging materials. However, there were significant differences in shelf life of fura stored at 5°C.