Linde Canada has developed a range of application-specific packaging solutions under it’s current MAPAX® brand to help serve the dairy, meat, dry foods and bakery, and fish and seafood industries.
The Canadian branch of the industrial gas company has worked with food research institutes, food-processing customers and packing suppliers to create its new modified atmosphere packaging (MAP) line and to determine the best atmosphere for each application.
This is influenced by the foodstuff and its properties, microbial activity, hygiene requirements, pre-packaging delay, temperature, permeability and other properties of the packaging material, the free gas volume with the package and the residual O2 level.
By analysing these properties, this technology can then determine which application to use. For example, in the case of low fat products with a high moisture content, MAPAX® focuses on inhibiting the growth of microorganisms, but in the case of products with a high fat content and low water activity, oxidation protection is the primary objective.
MAPAX® gas mixtures usually consist of carbon dioxide (CO2), nitrogen (N2) and oxygen (O2). Microbial growth can also be inhibited to a certain extent with the help of other gases such as nitrous oxide (N2O), argon (Ar) and hydrogen (H2), which can be applied individually or mixed according to specific ratios.
CO2 inhibits microorganisms, such as mould and other common aerobic bacteria, by dissolving into the food’s liquid and fat phase, therefore reducing its pH value and it penetrates biological membranes, causing changes in permeability and function. N2 is primarily used to replace O2 in packaging to prevent oxidation, due to its inert property. N2 also helps to prevent package collapse by maintaining internal volume because of it’s low solubility in water.
MAP is a natural method of preserving food in order to extend shelf life without altering the physical or chemical properties or adding any unnatural ingredients, and without the need for cryogenic freezing.