Estimating packaging atmosphere–temperature effects on the shelf life of cod fillets

The behaviour of the natural microflora (total bacterial count, psychrotrophic bacteria, total coliforms, and lactic acid bacteria) of fresh cod fillets packaged in air, under vacuum, in a modified atmosphere with low oxygen concentration (5%) and in a modified atmosphere with high oxygen concentration (80%) was monitored during storage at different isothermal conditions from 4 to 12 °C. The growth data of the total bacterial count and total coliforms were used to model kinetically the shelf life of the samples in order to check the effects of storage temperature and packaging atmosphere. The acceptability times were compared with the stability times to establish if the shelf lives predicted were correlated. At 4 °C, cod fillets packaged under vacuum and in a modified atmosphere with low oxygen concentration had a higher shelf life (6.00 and 5.42 days), calculated from the growth of the total bacterial count, than the samples packaged in other atmospheres (1.96 and 2.62). Kinetic modelling could be valuable for the prediction of microbial fish quality loss.