Controlled atmosphere packaging is a new type of food preservation technology which will replace the air in the package by mixed gas (usually CO2, N2 and O2 with certain proportion). It adopts the different role of such mixed gas to inhibit the growth of microorganisms which will cause food spoilage, and reduce the respiratory rate of active food (plant-based foods such as fruit and vegetable) . In this way, it will keep food fresh and extend the shelf life. The food in modified atmosphere package will maintain the original color, flavor, taste, shape and nutrition of the food.

For modified atmosphere packaging machine (MAP), the natural gas in the packages is replaced by the appropriate gas at a certain proportion (Nitrogen, Oxygen, Carbon Dioxide) for the product.
In order to maintain the shape, color and freshness of the product, the air in the modified atmosphere package is replaced by a mixture of gas suitable for the product. This modified atmosphere is usually composed of carbon dioxide, nitrogen and oxygen.

Qualified modified atmosphere packaging machine (MAP) should conform to two key requirements, they are: high gas replacement rate and low gas mixing accuracy error rate. These two key indexes are needed when judge the quality of MAP machine. Shanghai Sanjing Machinery Co., Ltd deeply know the importance of the above two points and keep working towards the best indicator and until now the result is very satisfactory!

When cooked food are packaged in modified atmosphere package (MAP), the mixing ratio of fresh gas is: nitrogen (N2) 64% ~ 66%, carbon dioxide (CO2) 34% ~ 36%, gas replacement rate ≥98%. Since many microorganisms (bacteria) need O2 to grow and reproduce, reducing oxygen content can slow down the growth rate of bacteria (except anaerobic bacteria). The results showed that the reasonable mixture of N2 and CO2 formed a broad spectrum of bacteriostasis, color and taste protection layer on the food surface, and preserved cooked food under low oxygen environment. Therefore, when the error rate and replacement rate of gas mixing precision cannot reach the target, its bacteria-inhibiting and fresh-keeping effect is basically ineffective.