Source obtained from:
Modified atmosphere is a common technical definition that describes the practice of modifying the composition of the internal atmosphere of a package (commonly food packages, but this technique is also used for drugs) in order to improve the shelf life.
The modification process often tries to lower the amount of oxygen (O2), moving it from 20% to 0%, in order to slow down the growth of aerobic lifeforms and the speed of oxidation reactions. The removed oxygen can be replaced with nitrogen (N2), commonly acknowledged as an inert gas, or carbon dioxide (CO2), which can lower the pH or inhibit the growth of bacteria.
Gases used in MAP
•CO2 – bacteriostatic and fungistatic properties; inhibits growth of spoilage bacteria
•O2 – normally excluded or set at low concentration because it promotes for eg, fat oxidation
•N2 – counteract package collapse caused by CO2 dissolving in food
- retards growth of aerobic spoilage by microbes
MAP is associated with chilled temperature. Eg, mooncake pastry is chilled to
prevent water loss
• MAP maintains high relative humidity and reduction in water loss
