Mathematical modeling of odor deterioration of millet (Pennisetum glaucum) dough (fura) as affected by time-temperature and product packaging parameters

Consumer panelists evaluated the influence of temperature (5, 25, 35degreesC), 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 (EA) of 29.98 U/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 (ΔH*) in both packages indicate that deterioration change in fura is exothermic. The higher values of EA and free energy of activation (ΔG*) for fura stored in LDPE packages indicate a large change in quality. However, the lower values of free energy of activation (ΔG*) and negative values of entropy of activation (ΔS*) 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 35degreesC in the two packaging materials. However, there were significant differences in shelf life of fura stored at 5degreesC.