Modified atmosphere packaging (MAP)

Modified atmosphere packaging (MAP) is one of the new scientific approaches in the packaging industry. This method focuses on increasing shelf life by reducing microbial activity. In this method, the shelf life of the materials is increased by reducing the oxygen level and injecting a combination of specific gases. Stay with Karya Polymer to learn more about this method.

Where did modified atmosphere packaging start?

In the 1930s, when vegetables and fruits were transported by ship, concentrated CO2 gas was used to increase shelf life. England was the first country to use the modified atmosphere system (MODIFIED ATMOSPHERE) to protect pork and fish meat. Since then, the use of this method has been expanded due to the increased need.

MAP as the newest food packaging method

The use of MAP food packaging method is important for several reasons. Presence of oxygen in the food container is one of the most important reasons for the growth of aerobic microbes and fungal molds. Also, the oxidative activities inside the container cause unpleasant taste and smell, color change and change in nutritional properties of the food.

The presence of moisture in food packaging can cause the growth of microbes and the formation of lumps in powdered products or the softening of crunchy foods. On the other hand, excessive dryness of the space inside the package causes dehydration of the food.

Therefore, one of the suitable methods to solve the mentioned problems is food packaging using the MAP method, which is expanding these days.

How does modified atmosphere packaging (MAP) work?

The concept of modified atmosphere packaging for packaged goods includes the modified atmosphere of a food product by vacuum, gas pressure or controlled permeability of the package. With this method, chemical, enzymatic and microbial activities are controlled, so that important risks that may occur are avoided or reduced.

In other words, packaging by the MAP method means entering the atmosphere in an envelope (or package) of food with a special combination of carbon dioxide, nitrogen and oxygen.

This preservation method enables the fresh quality of food products without heat and chemical treatment used by competitive preservation techniques such as canning, freezing, drying and other processes.

MAP techniques are currently used in a wide range of fresh or chilled foods, including semi-cooked foods, fish, fresh pasta, fruit and vegetables. Recently, it has been used for coffee, tea, ready meals and bakery products.

Advantages of modified atmosphere packaging

The food packaging with the method of modified atmosphere packaging has the following advantages:

1. Shelf life is prolonged by maintaining a desirable quality of materials.
2. Reducing the amount of waste and corruption
3. Keeping the product with fresh property without using preservatives or irradiation
4. Harvesting fresh product at the desired maturity levels for the consumer
5. Reduce shipping costs by providing additional storage time
6. Providing the possibility of producing cut products, ready for consumption
7. Saving energy (such as not using thermal and refrigeration processes)

A comparison of the shelf life of different products

Using the modified atmosphere method, in addition to maintaining the qualitative properties of the material, also increases the shelf life. One of the important features of this method is that it prevents the growth of aflatoxin and fungal agents, which solves the problem of exporting this product. Also, other tests conducted on fat, nutritional value, water and weight percentage of the product have shown that all these factors are present in pistachio in a completely optimal amount after six weeks (When pistachios are fresh, they are considered as vegetables and when they are dried, they are considered as dried fruits, which have a big difference in the amount of tax)

In the following table, there is a comparison of the shelf life of different products between the normal state and the state protected by a modified atmosphere.

How to use the MAP method?

First, it is necessary to make the desired gas with the desired composition. For this purpose, the atmosphere with the desired composition can be purchased from air separation factories in pressurized capsules.
To save money, the triple gases of nitrogen, oxygen and dioxide can be prepared in a pure form and mixed with the desired ratio using a gas mixer. In this method, there is no need to store the modified atmosphere in a separate tank, and the obtained mixed gas can be directly injected into the package. Usually, in atmospheric modified packaging, the air is removed from the package and refilled with gases whose mixture is known, and the lid is sewn.
In this method, the space around the food is continuously filled with gas. There are different machines for packaging and almost many devices are compatible with this method. Among these devices, the following examples can be mentioned:

1. Thermoforming
2. Horizontal and vertical flood shape
3. A reservoir

In this text, we get acquainted with modified atmospheric packaging, which has created a great transformation in the shelf life of products. This method greatly reduces the amount of additives used to preserve food. This is a good way for everyone to have access to fresh and healthy food.