Effect of storage temperature and gas permeability of packaging film on the growth of lactic acid bacteria and Brochothrix thermosphacta in cooked meat emulsions

The effect of gas permeability of packaging film on the growth of lactic acid bacteria and Brochothrix thermosphacta in cooked meat emulsions stored at 0, 8 and 15 °C was investigated. The estimated parameters from Gompertz equation for the assayed temperature-oxygen permeability combinations showed LAB development to be significantly greater than those of B. thermosphacta. The influence of the two sources of variation (oxygen permeability of packaging film and temperature) on the growth parameters of LAB and B. thermosphacta was analysed showing a significant effect (P<0.001) of the temperature on both bacterial population while the film permeability had only a significant influence (P<0.001) on B. thermosphacta growth. Under the conditions of this study the packaging film influenced the maximum counts and growth rates of both organisms. Since the inhibition of B. thermosphacta occurred when the meat product was vacuum-packaged in films possessing high oxygen permeability and the effect of pH was found not to be associated with the growth inhibition, accumulation of hydrogen peroxide produced by LAB may possibly be one of the main factors responsible for B. thermosphacta inhibition. Shelf-life of vacuum-packaged cooked meat emulsions in high oxygen transmission rate films will be guarantied and a temperature abuse will not result in an increase of spoilage by LAB.