Consumers are demanding "fresh" food wherever and whenever possible whilst wanting a long shelf life. This has created a significant problem for manufacturers trying to meet these demands and keep the food safe.

Dairy foods are often recommended by nutritionists to provide calcium and fat soluble vitamins. This makes them one of the food types that are the focus for meeting consumer demands whilst maintaining food safety.

"Preservative " is a dirty word to the consumer and there are specific requirements for the use of them in the Food Standards Code, so these chemicals are being used significantly less.Other ways of achieving preservative are being used and investigated.

Modifying the atmosphere in the packaging of cheese and other foods is one way that is now commonly used by manufacturers to extend shelf life and convenience, and is known as MAP. It involves the use of special packaging material as well as specific gases and amounts to reduce bacterial growth.

However the problem here, is that whilst making it difficult for most food poisoning bavcteria to grow, this MAP creates an perfect environment for other pathogens. Especially when the MAP food is stored and displayed at cold temperatures.Listeria species are an example and these are now involved in around 15 product recalls per year in Australia.

Much research is happening on MAP of cheese and it recognised that the type and nature of the cheese will require different types and levels of atmosphere modification. Hard cheeses will require less modication of the atmosphere due to a lower moisture content, whereas soft cheeses will require more. A recent paper about this research can be found at http://www.springerlink.com/content/0hg1325278t01w24/