Definition of modified atmosphere packaging
According to the official statement of the U.S. Food and Drug Administration (FDA)， modified atmosphere packaging is a packaging way to involves either actively or passively controlling or modifying the atmosphere surrounding the product within a package made of various types and/or combinations of films
The main purpose of modified atmosphere packaging is to prolong the freshness of food in the packaging bag as much as possible. Since 2020, COVID-19 has been affecting the lives and work of people all over the world. It is not convenient for people to go to the grocery store or wet market to buy fresh food, and the vegetables and meat in boxes or bags need to use packaging that can maintain a longer shelf life.
In addition, some air-sensitive foods also require modified atmosphere packaging as a new type of packaging bag to maintain the food flavor for a long time. For example, tea and coffee, need to be kept in a dry and sealed environment to maintain the purity of the taste. To avoid oxidation due to the contact between the air in the packaging bag and the coffee or tea, resulting in deterioration, etc.
Different types of modified atmosphere packaging
If the air replacement method in the packaging bag is used as a classification factor, we can divide the modified atmosphere packaging into two different categories: active modified atmosphere and passive modified atmosphere.Active modified atmosphere packaging usually uses manual intervention to replace other gases in the original packaging bag with the required gas. Taking coffee bag packaging as an example, in order to avoid the oxidation reaction of coffee beans or coffee powder with air and affect the taste, we often inject nitrogen into coffee packaging bags to replace air. Because nitrogen is an inert gas, it will not oxidize with coffee beans or coffee powder, so it can maintain the pure taste of coffee for a long time.Passive modified atmosphere packaging generally does not require too much manual intervention. In order to achieve the effect of modified atmosphere, a specific outer packaging film is often used. The most common form of this type of packaging is the plastic bag film seal for food and vegetables. In the production process of special food packaging film, the air in the food or vegetable packaging box is controlled to replace the air in the external environment by changing the air tightness of the film.
Common Active Modified Atmosphere Packaging One: filling of inert gas
In addition to the gas filling in the coffee packaging bag mentioned above, there are many common things that use inert gas filling to ensure that the food in the packaging bag does not deteriorate. For example, for our common potato chips, a large amount of inert gas is often injected into the potato chip bag during the production and packaging.After there is a large amount of inert gas in the potato chip bag, on the one hand, it can isolate the potato chips from the oxidation and deterioration of the air. On the other hand, the chips themselves are crunchy and prone to shattering in transit. A large amount of inert gas filling can effectively prevent the potato chips from breaking due to deformation of the packaging bag.
Common Active Modified Atmosphere Packaging Two: Install a gas regulating valve on the packaging bag
The gas regulating valve is not a simple two-way air displacement, it only allows one-way gas discharge. This gas regulating valve is often seen in coffee packaging. Because coffee beans in the storage process, will produce carbon dioxide due to oxidation. Carbon dioxide in a closed coffee bag will gradually expand the coffee packaging bag. This is caused by the increased air pressure in the coffee bag caused by the excess carbon dioxide being emitted nowhere.In order to avoid the coffee packaging bag bursting due to high air pressure, the coffee will deteriorate. We tend to choose prefabricated bags with gas regulating valves to package coffee when packaging coffee. By controlling the gas adjustment valve, the carbon dioxide in the coffee packaging bag can be eliminated in time, so as to maintain the pure quality of the coffee for a long time.
Common passive modified atmosphere packaging One: The use of low density polyethylene film
We know that during the storage process of food, especially fresh vegetables, ripening gas will be continuously released. If it is not discharged in time, the spoilage process of fresh vegetables will be accelerated. However, the process of gas emission obviously cannot be used to directly lift the film, because such an operation will consume a lot of manpower, and at the same time, it is easy to expose fresh vegetables to external bacteria and viruses, resulting in food contamination.In order to solve this problem, we usually use three materials of low density polyethylene (LDPE), polyvinyl chloride (PVC) and polypropylene (PP) as the packaging film for fresh food. These low-density films have good ductility, can effectively isolate external environmental pollution, and can also effectively prevent the penetration of moisture and oxygen in the packaging box.Therefore, by adjusting the air-tightness of the safety film covered on the outside of the food box to replace the gas inside and outside, it is a passive air-conditioning method, and it is also a common practice for a long-term preservation of large quantities of vegetables and meat. With COVID-19 affecting human lifestyles, this gas approach is becoming more and more popular.
Common passive modified atmosphere packaging Two: place oxygen scavenger and desiccant in the packaging bag
The most common form of this modified atmosphere is the bottle packaging of pills and health products. They are also often seen in some snacks and individually wrapped small cakes. Different desiccants will have different components for different drying needs, and the common ones are the mixture of iron powder and ascorbic acid, as well as activated carbon and other components.The purpose of both desiccants and oxygen scavengers is to prevent oxidation and deterioration of stored food. But there are some differences in how the two work. The purpose of the desiccant is to absorb the moisture in the air, and the scavenger is to combine with the oxygen molecules in the air to prevent bacteria from growing in an aerobic environment.
The specific application of modified atmosphere packaging
Roast packaging for coffee
Coffee beans release carbon dioxide when they are roasted. Before the invention of modified atmosphere packaging bags, we generally used to let the coffee beans cool naturally before putting them in the packaging bags. Such an operation will face a problem: the roasted coffee beans are exposed to moisture in the air, and there is the possibility of mold and deterioration.After using modified atmosphere packaging, roasted coffee beans can be packaged directly into bags. After a period of placement, there may be a certain amount of carbon dioxide in the coffee bean packaging bag, so open the gas regulating valve to release it.
Legal marijuana packaging
The sale of marijuana is legal in some countries and some states in the United States. In order to create a better consumer experience, cannabis distributors need to keep their cannabis products fresh for longer. When marijuana is mixed with oxygen, THC cannabinoids are converted into CBN cannabinoids, which seriously affects the taste and hallucinogenic effects of marijuana.This packaging demand has prompted packaging machine manufacturers to develop different types of gas-regulated packaging bags to ensure that cannabis can maintain fresh and stable quality and taste during long-term storage.
Food preservation and storage
A common practice for meat insurance is refrigerated transport and storage. But this method will greatly increase the operating cost of the enterprise. Using raw materials such as low-density polypropylene film as the packaging gas adjustment method for meat and fresh vegetables can isolate meat and fresh vegetables from contacting bacteria in the external environment. If filling with inert gas during packaging, it can better extend the shelf life of food.
The introduction of modified atmosphere packaging machine
Modified atmosphere packaging machine is a packaging machine designed to use air conditioning to control the gas composition in the packaging bag to extend the shelf life. There are many different types of modified atmosphere packaging machines depending on the type of objects to be packaged and bags. If you have the needs of modified atmosphere packaging machines, you can contact our professional engineers for free consultation and get related modified atmosphere packaging solutions.
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