Modified Atmosphere Packaging is considered a revolutionary technique that extends the shelf life of perishable goods. By altering the composition of gases inside the packaging, MAP helps maintain the freshness, flavor, and quality of food products. The article below delves into the details of MAP, its users, how it works, its pros and cons, and its safety.

What Is Modified Atmosphere Packaging?

Modified Atmosphere Packaging (MAP) is a technology used to extend the shelf life of fresh food products. It involves modifying the internal atmosphere of the packaging by altering the proportions of gases such as oxygen, carbon dioxide, and nitrogen. This creates an optimal environment that slows down the natural decay process and prevents spoilage.

Types Of Modified Atmosphere Packaging

Gas Flushing

Gas flushing is a method where the air inside the packaging is replaced with a controlled mixture of gases, typically a combination of carbon dioxide (CO₂), nitrogen (N₂), and oxygen (O₂). The specific mixture depends on the type of food product being packaged.

• Air Removal: The natural air in the package is evacuated.
• Gas Injection: The package is then filled with the desired gas mixture.
• Sealing: The package is hermetically sealed to maintain the gas mixture.
• Applications: Widely used for meat, poultry, seafood, bakery products, and dairy items.
• Benefits: Extends shelf life, maintains product appearance and quality, reduces spoilage.

Barrier Packaging Films

Barrier packaging films are specialized materials designed to control the exchange of gases and moisture between the inside of the package and the external environment. These films have specific barrier properties tailored to the needs of different food products.

• Materials: Can include combinations of plastics, aluminum, and other polymers.
• Types:
• High Barrier Films: Prevent the entry of oxygen and moisture.
• Selective Permeability Films: Allow specific gases to pass through, beneficial for respiring products like fruits and vegetables.
• Applications: Used for products requiring strict control over moisture and gas exchange, such as snacks, coffee, and fresh produce.
• Benefits: Maintains the desired internal atmosphere, enhances product protection, and improves shelf life.

Scavenger Or Desiccant Packs

Scavenger or desiccant packs are included within the packaging to actively absorb or emit specific gases or moisture to maintain the desired conditions inside the package.

• Types:
• Oxygen Scavengers: Absorb residual oxygen to prevent oxidation and spoilage.
• Moisture Absorbers: Maintain optimal humidity levels to prevent mold and spoilage.
• Carbon Dioxide Emitters/Absorbers: Maintain CO₂ levels to inhibit microbial growth.
• Applications: Commonly used in the packaging of meats, baked goods, pharmaceuticals, and electronics.
• Benefits: Extends shelf life, maintains product quality, and prevents microbial growth.

On-Package Valves

On-package valves are one-way valves integrated into the packaging that allow gases generated within the package (such as CO₂ from fresh produce or coffee) to escape while preventing external gases from entering.

• Design: Typically, a small plastic or rubber valve is embedded in the packaging material.
• Function: Automatically releases excess gas build-up, maintaining the internal atmosphere.
• Applications: Used for coffee, fresh produce, and other products that generate gases during storage.
• Benefits: Prevents package rupture, maintains product freshness, and controls internal pressure.

Who Uses Modified Atmosphere Packaging?

MAP is widely used across various segments of the food industry, including:

• Meat and Poultry: To prevent discoloration and spoilage.
• Seafood: To maintain freshness and reduce the risk of bacterial growth.
• Fruits and Vegetables: To slow down ripening and prevent spoilage.
• Coffee Beans: When coffee beans are roasted, they release Carbon Dioxide, and without the use of modified atmosphere packaging, the beans must cool completely before being packaged or else the build-up of CO2 gas can cause the packaging to burst open.
• Bakery Products: To extend the freshness and prevent mold growth.
• Dairy Products: To maintain quality and extend shelf life.
• Ready-to-Eat Meals: To preserve taste and nutritional value while extending shelf life.
• Legal Cannabis Industry: Some legal cannabis companies are using modified atmosphere packaging and Nitrogen gas to flush out extra Oxygen and extend shelf life.

How Does Modified Atmosphere Packaging Work?

Shorten shelf life by increasing respiration rates. Oxygen produces lipid oxidation reactions. This causes high respiration rates in fruits and vegetables. 

The presence of oxygen encourages the growth of aerobic spoilage. The potential formation of other unwanted microorganisms may also occur.

So, we can reduce or delay unwanted reactions by minimizing the amount of oxygen and replacing it with other gases. To change the atmosphere of a package, the oxygen contained within must be reduced or removed.

The MAP process lowers the volume of oxygen contained within the space of the packaging containing the product. It can also prevent the formation of water vapor. The oxygen inside of the package is often replaced with other gases.

Pros Of Modified Atmosphere Packaging

• Extended Shelf Life: Significantly prolongs the freshness and edibility of food products.
• Improved Quality: Maintains the color, texture, and nutritional value of food.
• Reduced Waste: Decreases food spoilage, contributing to lower food waste.
• Enhanced Safety: Reduces the growth of spoilage organisms and pathogens.
• Economic Benefits: Allows for longer storage and transport periods, expanding market reach.

Cons Of Modified Atmosphere Packaging

• Cost: Higher initial setup and operational costs due to specialized equipment and materials.
• Complexity: Requires precise control and monitoring of gas mixtures and packaging integrity.
• Potential Gas Imbalances: Inaccurate gas composition can lead to spoilage or quality degradation.
• Environmental Impact: The use of non-recyclable or non-biodegradable materials can contribute to environmental pollution.

Is Modified Atmosphere Packaging Safe?

MAP is not to be considered a fail-safe when it comes to food safety. Because some foods packaged by MAP may result in additional risk. The modified atmosphere may allow for the formation of pathogenic organisms. And there are several possible contamination issues with pathogens, including but not limited to L. monocytogenes, Y. enterocolitica, and A. hydrophila.

However, actual cases are few and far between. They have been relatively uncommon since the inception of the use of modified atmosphere packaging.

Conclusion

Modified Atmosphere Packaging is a powerful technology that enhances the preservation of perishable food products, extending shelf life and maintaining quality. While it comes with certain costs and complexities, the benefits of reduced food waste, improved product safety, and economic advantages make it a valuable tool in the food industry. As technology advances, MAP continues to evolve, offering even greater potential for maintaining the freshness and safety of our food supply.