With prepared foods, the rate of deterioration depends on the ingredients and varies considerably from one product to another. Take meat-based ravioli or lasagna, for example. The meat spoils at a different rate than the pasta.
One of the major challenges associated with prepared foods is how to avoid introducing microbial contamination during the manufacturing process. To achieve this, manufacturers must ensure the highest standards of hygiene and the highest-quality raw materials.
The most serious breakdown processes are caused by the growth of microorganisms, oxidation and staleness. This results in rancidity, discoloration and loss of taste. A fresh pizza, for example, left out in the open air at 4°C to 6°C (39.2 to 42.8ºF), spoils in about a week. However, it can last for several weeks with the right modified atmosphere combining a low oxygen (O2) concentration with a high carbon dioxide (CO2) level. In the case of pizza, the concentration of O2 should be less than 1.5%.
The relationship between CO2 and nitrogen (N2) in prepared food packages is mainly determined on the basis of the moisture content of the product, but also on the composition of the food. This influences the speed of microbial growth, oxidation and enzymatic activity. The higher the water activity, the higher the concentration of CO2 required in the package.
Multi-Component Products are a Case in Point
Prepared foods can spoil very quickly in the wrong environments. This applies in particular to foods with a neutral pH value. Each prepared dish presents its own challenges. Products with diverse and variable components (such as sandwiches, filled pasta, salads, pizza and spring rolls) are particularly challenging.
As each ingredient has its own properties, in-depth knowledge is required to find the gas mixture that will best inhibit deterioration and maintain quality. Our MAPAX solutions can make a valuable contribution to preserving quality and extending shelf life.