what is Modified atmosphere packaging? | RESURE

What is Modified Atmosphere Packaging?

        Modified Atmosphere Packaging also known as displacement gas packaging, or MAP for short can be defined as "a technology that regulates the gas environment of food in materials that prevent gas from entering and exiting." Specifically, air conditioning reduces the oxygen content in the ambient gas while maintaining a suitable low temperature, and appropriately changes the composition ratio of carbon dioxide and nitrogen.

        An important feature of MAP is to adjust the gas composition in the packaging at the beginning of storage, so as to inhibit the rot and deterioration of food, maintain the quality of perishable food during the normal shelf life or prolong its shelf life. Therefore, modified atmosphere packaging is also called Active Atmosphere Packaging. Modified atmosphere fresh-keeping gas is generally composed of carbon dioxide (CO₂), nitrogen (N₂), oxygen (O₂), and a small number of special gases (NO₂, SO₂, Ar, etc.). The functions of various gases are as follows:

CO₂: can inhibit the growth and reproduction of most spoilage bacteria and molds, and is the main antibacterial agent in fresh-keeping gas;

  O₂: can inhibit the growth and reproduction of most anaerobic spoilage bacteria, maintain the color of fresh meat, and maintain fresh fruits and vegetables. The role of respiratory metabolism in the fresh state;

  N₂: is an inert gas, which generally does not react chemically with food and is not absorbed by food. It is used as a filling gas in modified atmosphere packaging to prevent the package from collapsing due to CO₂ and other gases escaping from the package.

        For different foods, fruits, and vegetables, the composition and proportion of the fresh-keeping gas are also different. The key to the modified atmosphere packaging of crops is to keep the oxygen permeability of the packaging material to match the breathing rate of the product.

                    Gas ratio and preservation time of common food

Reasons why fruits and vegetables need modified atmosphere packaging

        Fruits and vegetables still have vitality after being harvested, and the energy required for their life activities is obtained by decomposing the nutrients accumulated during the growth period through respiration. Therefore, the essence of fruit and vegetable preservation is to reduce the respiration of fruits and vegetables to reduce the consumption of nutrients.

        Modified atmosphere packaging can use modified atmosphere fresh-keeping gas (2-4 kinds of gases are mixed according to the ratio of food characteristics) to replace the air in the packaging or packaging bag, change the external environment of the food in the box (bag), and inhibit bacteria (microbes) The growth and reproduction of fresh fruits and vegetables slow down the metabolism of fresh fruits and vegetables, thereby prolonging the freshness period or shelf life of food. Therefore, if you want to prolong the freshness of fruits and vegetables, modified atmosphere packaging is a perfect choice.

Requirements for equipment for fruit and vegetable packaging:

1. Ensure the balance of modified atmosphere in the packaging box (bag) (the unique modified atmosphere preservation technology of fruits and vegetables directly determines the length of the preservation period)

2. Ensure the accuracy and stability of the fresh-keeping gas ratio, with an error of <1% (high-precision fresh-keeping gas ratio can ensure the stability of the fresh-keeping period

3. Uniform heat-sealed packaging and beautiful appearance (increasing the appearance value of packaging products)

4. High-speed packaging (reducing production costs)

5. The stability of packaging equipment (reduce the risk of food safety and reduce maintenance costs)

6. Refrigerated environment: Temperature is one of the most important factors in modified atmosphere packaging. Boxed food packaged in a modified atmosphere must be delivered under cold chain conditions of 0~4°C

7. Packaging materials: Bad packaging materials will have a mist on the surface after refrigeration, which will affect the visual appearance of the product. High-permeable and anti-fog products are the first fruit and vegetable packaging choice.

Next issue preview: How to choose a modified atmosphere packaging machine