What modified atmosphere for the conservation of cheese and dairy products?

What is modified atmosphere packaging?

Pre-packaged and ready-to-eat food products are on the rise. They meet consumer expectations in terms of ease of use but also new formats and innovative concepts.

Modified atmosphere packaging aims to eliminate or reduce physical, enzymatic and microbial degradation which spoils foods, whether processed or not. It consists of replacing the air surrounding a product with an appropriate atmosphere, with the aim of extending its shelf life. It is aimed at all types of products: meat, fish, fruits and vegetables, dried products, etc. Packaged in optimal conditions, at the right temperature, they retain all their quality (freshness, colour, taste). The process also makes it possible to reduce the content of additives and chemical preservatives used.

Which gas to increase the shelf life of cheese and dairy products?

Cheeses and dairy products correspond to a large family of food products (from powdered milk to cottage cheese) for which the gas or gas mixture to be used will mainly depend on the moisture content (causing very serious conservation problems). different).

Given the natural presence of micro-organisms in dairy products, packaging in a modified atmosphere is possible and effective on cheeses which are almost inert (PP, cooked PP, PF) or which tolerate anoxia well (PF).

• Dry or dehydrated products (milk powders)

These are products that are particularly sensitive to oxidation (rancidity). Removing oxygen from the air and replacing it with nitrogen (inert gas) is necessary to prevent fat oxidation.

• Intermediate humidity products (cooked pressed cheeses)

For these products, the risk of microbiological development during storage, in particular the development of mold, is to be feared. It will be appropriate to use pure carbon dioxide or a mixture of carbon dioxide and nitrogen in a proportion depending on their humidity level and the microbial flora present.

Remember: CO2 slows the growth of bacteria and mold.

Recommendations from our experts:

• -grated cheese: 100% N2 or 30% CO2 / 70% N2 (“aerated” product in very slightly inflated packaging),
• -portioned cheeses: mixture with a high CO2 content to obtain well-plated packaging,
• -soft cheeses (flowery rinds): the maturation phase must be able to continue during storage, which requires a significant supply of O2 (the flowery rind has a high respiratory intensity and therefore quickly deteriorates into anoxia; it liquefies and the cheese no longer develops normally.
• Products with high humidity (fresh cheeses, uncooked pressed pasta)

These products are particularly sensitive to oxidation (rancidity) as well as degradation mainly linked to yeast. It is appropriate to use a gas mixture, 30% CO2 / 70% N2, in order to inhibit microbial growth and rancidity by oxidation.

For blue-veined pasta, 100% N2 or 20% CO2 / 80% N2 maximum packaging will be required in order not to have too much impact on the action of mold.
For creams, 100% nitrogen will also be recommended (or nitrous oxide - N2O in the case of spray whipped creams).