Modified Atmosphere Packaging and Food Safety, 1991 Polymers, Laminations & Coatings Conference Proceedings

Modified Atmosphere Packaging (MAP) is a food and packaging technology involving inhibiting the normal microbiological and biochemical deterioration of food, by altering and, in some cases, maintaining a different composition of headspace gases. It has many benefits, including longer shelf life, less food waste, convenience, and superior quality.

While the potential of MAP is significant, so are the risks. The reason is that, in some cases, the normal "benign" spoilage microorganisms that result in an objectionable product are replaced with pathogenic (disease causing) organisms which can only grow under MAP and which may not affect the appearance and odor of the food.

A case study is described which illustrates how an unintentional passive MAP package for a raw product (mushrooms) in the People’s Republic of China resulted in an outbreak of food poisonings in canned mush-rooms in the U.S. The problem resulted from packing raw mushrooms in L.D.P.E. (low density polyethylene bags) which with extended shipping time resulted in a depletion of oxygen and increase of carbon dioxide, killing off the normal spoilage microorganisms, while allowing the opportunity for a far more deadly organism to flourish.

The conclusions are that the process of producing, harvesting, processing, packaging, and distributing a food is a fragile, interdependent system. To be successful, MAP requires greater attention to all of these areas, not less.