Which factors impact the effectiveness of Modified Atmosphere Packaging for food?

If you are packaging fruit and vegetables, or meat or poultry, spoilage is a key concern.

From the moment animals are slaughtered and fruits and vegetables are harvested, they immediately begin to spoil. Often, the more these foods are processed, as in the case of diced fruit and minced meat, the quicker they will spoil. Different foods are suitable for consumption for different periods of time. Things like their salt and water content, storage conditions, hygiene conditions during production and pH value all impact how long a certain food is suitable for consumption. These factors also influence how sensitive a food product will be to microbial or biochemical/chemical spoilage.

Microbial Spoilage

Microorganisms can have a significant impact on food quality and shelf-life. Aside from their potential to affect colour and smell, they can also prove to be major health hazards, rendering a product inedible.

Chemical and Biochemical Spoilage

Once an animal has been slaughtered or plant material has been harvested, chemical reactions take place which affect the food structure and quality. These chemical processes can be beneficial in some instances, such as for the dry aging of meat. For the most part however, they are detrimental to product quality as the quality of organic material tends to decrease. For example, a product can become rancid as a result of its fats oxidising.

Fortunately, the changes caused by microbial and chemical spoilage can be slowed significantly by using the right MAP techniques. Various gases and gas mixtures with different properties can be used to slow spoilage as much as possible; therefore extending product shelf-life.

Nitrogen Packaging

Nitrogen is one such gas which can be used for MAP to slow product spoilage. Nitrogen, an inert gas which can be supplied to meet food grade purity specifications, is used to displace air, particularly oxygen, from food packaging. Not only does this prevent the oxidation of food, i.e. biochemical spoilage, it also inhibits the growth of aerobic microorganisms, discouraging microbial spoilage too.

Food grade nitrogen for nitrogen packaging

If you would like to use nitrogen for MAP, one solution is to use a nitrogen gas generator. A nitrogen gas generator generates gas on-site and on demand, whenever it is required and at the purity specification required (food grade nitrogen is typically >99% purity). This is a great benefit when it comes to food packaging as a gas supply from a properly maintained gas generator will never run-out mid production, as can happen with nitrogen gas cylinder and LN2 microbulk supplies. A nitrogen gas generator also eliminates the need for repeated orders, deliveries, manual handling, change-overs and storage, making it the most convenient method of MAP gas supply.