Do Not “Pack and Pray”: Use Predictive Models to Assess the Microbial Safety and Shelf-Life of Modified Atmosphere Packaged Foods

Besides protecting food from contact with the external environment and from airborne contamination, packaging can also contribute to prolong food shelf-life and increase food safety. The gaseous environment within a package can delay or inhibit microbial growth or modify the microbial ecology of the product. Evaluating the microbiological safety and the shelf-life of foods through predictive microbiology tools implies developing or selecting appropriate models that consider the impacts of different static and/or dynamic concentrations of O2, CO2, and N2 on the behavior of spoilage and pathogenic microbiota. There is an increasing demand for predictive models that would allow one to identify in advance the headspace gas composition and the packaging material suitable for increasing food safety and shelf-life. The development of such numerical tools would decrease the number of time-consuming challenge-testing experiments necessary for experimentally quantifying and assessing the microbial fate in terms of changes in headspace composition. The objective of the present chapter is to provide information on the adequate development, validation, and interpretation of predictive microbiology models, including the effect of packaging atmosphere to achieve more reliable estimates of microbial behavior in packaged foods. A case study on a validated predictive model in cooked meat products is presented using the MicroHibro software tool.