Processed food is more popular today than ever before. This is partly because of the convenience it offers and partly because you can consume a greater variety of food without having to learn how to cook it. But processed food needs to go through a rigorous process before it makes its way to your nearest superstore. It needs to be manufactured and packaged in a certain way to maintain its freshness.

Source: Levapack

One way factories use to preserve processed food is by removing oxygen from the containers and replacing them with nitrogen. But how does nitrogen keep your food fresh? Keep reading to know more!

Which Foods Use Nitrogen Packaging?

Potato Chips & Puffy Snacks
Nuts & Seeds
Crackers & Pastries
Coffee (Ground & Whole Bean)
Infant Formula
Pre-packaged Salads & Cut Vegetables
Sliced Deli Meats
Canned/Bottled Beer & Wine

How Does Nitrogen Extend Shelf Life?

Below are the reasons why nitrogen gas is used by food packaging industries.

1. Nitrogen Gas is Safe

Packagers widely use the nitrogen flushing method for preserving and storing their products because nitrogen is a non-reactive gas. It is non-odorous and non-toxic. Plus, it is readily accessible. In fact, it makes up 78% of the atmosphere. These characteristics make storing food using nitrogen affordable and safe.

Source: The Hong Kong University of Science and Technology

2. It Prevents Oxidation

Since oxygen gas is a very powerful oxidizing agent, it causes spoilage when it reacts with compounds such as sugars and fats. For example, have you noticed how an apple turns brown after you bite it? That is because of the oxidation process taking place. Nitrogen gas doesn’t have the same properties and is safe to use.

Source: VinePair

3. It Prevents the Growth of Dangerous Bacteria

The majority of microorganisms, like mold, yeast, and aerobic bacteria use oxygen to survive and grow. The availability of oxygen in the food can cause the growth of dangerous bacteria that increases its spoilage rate. By replacing oxygen with nitrogen, contamination by bacteria can be reduced. Using nitrogen for preserving your products is also important because it can fill up all of the spaces in your packaging to prevent moisture from getting in.

Source: WebMD

4. It Prevents Packages From Collapsing

One more reason why packagers prefer nitrogen flushing is that nitrogen can create a pressurized atmosphere, preventing packages from collapsing. Using nitrogen gas for this purpose helps make sure that delicate food like crackers and chips will not get crushed inside the bags.

Source: Parker

Modified Atmosphere Packaging machines allow packagers to easily displace the oxygen inside containers with nitrogen onsite. This reduces the waste produced by your company and saves a lot on your expenses per year.

How Does Nitrogen Flushing Preserve and Protect Food?

Packaging Manufacturers need to package processed food carefully so that it can withstand the transportation process. To reach this goal, packagers use the Modified Atmosphere Packaging (MAP) method. Here’s a look at how MAP works:

Nitrogen flushing is a type of MAP and is similar to vacuum packaging. The main difference between vacuum packaging and nitrogen flushing is that nitrogen flushing uses nitrogen gas to reduce the amount of oxygen in the container while vacuum packaging simply vacuums the air out of the containers.

In the MAP method, they consider the food’s respiration level because respiration can determine the optimal type and quality of air needed to keep the food fresh. When packaging food, manufacturers use nitrogen filling and sealing machines and pack them with high permeability or low permeability membranes depending on the food’s respiration degree.

For instance, fruits and vegetables usually have higher respiration so they will require some gas exchange to stay fresh. The MAP method helps you determine the optimal membrane type for packaging the fruit or vegetable product to prevent early spoilage.

On the other hand, food products that don’t respirate like spices, cheese, and chips are packaged using low permeability membranes which prevent gas exchange. This maintains the optimal atmosphere needed to prevent spoilage inside the containers and ensures the food is fresh until it reaches the consumers.

If you’re interested in learning more about nitrogen packaging technology, check out Nitrogen Flush Packaging: What Is It and How to Use It? for a comprehensive guide on how this technique works and how it can be applied to various products.

Nitrogen Flushing vs. Vacuum Packaging: Which is the Right Choice?

While both nitrogen flushing and vacuum packaging aim to extend shelf life by removing oxygen, they operate on fundamentally different principles and are suited for different applications. Understanding these differences helps clarify why manufacturers choose one method over the other for various food products.

Feature Comparison	Nitrogen Flushing	Vacuum Packaging
Core Principle	Displacement Method: Air is first removed from the package and then replaced with high-purity nitrogen gas.	Removal Method: Almost all air (including oxygen) is simply suctioned out of the package, creating a vacuum.
Package Appearance	The package is puffed up and firm, with the internal gas acting as a cushion.	The packaging shrinks tightly and conforms to the shape of the food inside.
Physical Protection	Excellent. The nitrogen gas acts like an "airbag," effectively preventing delicate items like chips, crackers, and pastries from being crushed during transport and handling.	None. The tight shrink-wrap offers no protection against crushing and can even damage fragile foods.
Best-Suited Foods	Delicate, brittle, or powdered foods: Potato chips, cookies, instant coffee, infant formula, fresh-cut salads.	Solid, non-fragile foods: Blocks of meat, sausages, hard cheeses, rice, beans, cured products.
Effect on Anaerobes	The nitrogen atmosphere inhibits aerobic bacteria, but has a limited effect on anaerobic bacteria (which don't require oxygen).	The low-oxygen environment also inhibits aerobic bacteria, but may create favorable conditions for certain anaerobes (like Clostridium botulinum), which is why it's often combined with other preservation methods like refrigeration.

How Long Does Nitrogen-Packed Food Last?

Source: Pinterest

Using the modified atmosphere packaging technique for packaging foods and beverages can extend their shelf lives dramatically. Below is a table comparing the shelf life of typical food products packaged with and without nitrogen flushing.

Food Product	Shelf Life of Product With Nitrogen Flushing	Shelf Life of Product Without Nitrogen Flushing
Beverages	1-3 weeks	3-7 days
Beef Jerky	1-2 years	6 months
Dried Foods	1-2 years	6 months
Pureed Foods	1-3 weeks	3-7 days
Fresh Vegetabless	1-3 weeks	3-6 days
Fresh Fruit	1-4 weeks	3-6 days

If you’re interested in how nitrogen packaging can extend the shelf life of food products, you can read more in Nitrogen Flushing For Longer Canned Powdered Milk Shelf Life . This article explains how nitrogen flushing effectively prolongs the shelf life of canned powdered milk.

FAQs

Is the nitrogen in food packaging safe?

Yes, completely safe. Nitrogen is an inert, non-toxic, and odorless gas that makes up about 78% of the air we breathe. The small amount of nitrogen that escapes when you open a package immediately mixes with the surrounding air and has no effect on the human body. It is very safe and is widely used in the global food industry as a food-grade gas.

Why do chip bags seem to be half-filled with "air"? Is this a trick to give you fewer chips?

This isn’t meant to deceive consumers. The gas in the bag is nitrogen, and it serves two main purposes: first, it acts as a “cushion” to protect the fragile chips from being crushed during shipping and handling; second, it displaces oxygen to prevent the oils in the chips from oxidizing and going stale. The full-looking bag is necessary to ensure you get intact, fresh chips.

Are other gases besides nitrogen used in food packaging?

Yes. Sometimes carbon dioxide (CO2) or a mixture of nitrogen and carbon dioxide is used. Carbon dioxide is more effective at inhibiting the growth of mold and certain bacteria and is often used for packaging fresh meat, cheese, and baked goods to extend their shelf life.

Can I do nitrogen flushing at home for my own food storage?

While theoretically possible, it is neither convenient nor cost-effective for the average household. The food industry uses professional nitrogen generators and gas-flushing packaging equipment, which are expensive. For home preservation, a vacuum sealer is a more realistic and economical choice, especially for non-fragile foods like meat and grains.

Does food rot in a vacuum?

It slows decay significantly by removing oxygen, but some anaerobic bacteria can still grow. Unlike a vacuum, nitrogen packaging also provides a protective cushion.

Conclusion

The presence of oxygen inside packages introduces moisture and this can deteriorate your food product’s quality. The use of nitrogen gas has long been used by packaging manufacturers for preserving the quality, integrity, and freshness of their products starting from the factory to their consumers’ homes. It is a safe method widely used in the industry. They often use nitrogen flush packaging to remove the oxygen from the containers before the sealing process. You can also check out more can filling machines and can sealing machines here in Levapack.

Food Packaging – How Does Nitrogen Keep Food Fresh?

Food Packaging – How Does Nitrogen Keep Food Fresh?

Contents

Which Foods Use Nitrogen Packaging?