Applicability of an Arrhenius model for the combined effect of temperatureand CO2 packaging on the spoilage microflora of fish

The temperature behavior of the natural microflora on the Mediterranean fis h red mullet (Mullus barbatus) was examined as a case study. The growth of the spoilage bacteria Pseudomonas spp., Shewanella putrefaciens, Brochothri x thermosphacta, and lactic acid bacteria was modeled as a function of temp erature and the concentration of carbon dioxide in modified atmosphere pack aging. Combined models were developed and comparatively assessed based on p olynomial, Belehradek, and Arrhenius equations. The activation energy param eter of the Arrhenius model, E-A, was independent of the packaging atmosphe re and ranged from 75 to 85 kJ/mol for the different bacteria, whereas the preexponential constant decreased exponentially with the packaging CO, conc entration. We evaluated the applicability of the models developed by using experimental bacterial growth rates obtained from 42 independent experiment s pel formed with three Mediterranean fish species and growth rates predict ed from the models under the same temperatures and packaging conditions. Th e accuracy factor and bias factor were used as statistical tools for evalua tion, and the developed Arrhenius model and the Belehradek model,pere judge d satisfactory overall.