Oxygen is the biggest enemy of food. The presence of even the tiniest amount of oxygen inside a packaged food product can cause it to spoil quickly. Aerobic bacteria, molds, and yeast may also grow and damage the product. These can be dangerous to the health of the consumers and result in costly damages to companies. Thus, they need to find a way to get rid of the oxygen prior to the sealing process.
There are two popular methods used by the food and beverage industry that can effectively prevent oxygen damage: vacuum packaging and nitrogen flush packaging. Do you want to know the difference between these two practices and which one is more effective in keeping packaged food fresh? Keep reading to know more!
The vacuum packaging method is a way of increasing the shelf life of a food product by sucking out the air inside the containers first before sealing them. However, since it is impossible to make a complete vacuum, a specific amount of oxygen will still remain inside the packages.
The atmosphere contains 21% oxygen at a 1,000-millibar atmospheric pressure. As the oxygen is withdrawn by the vacuum packaging machine during the sealing process, the atmospheric pressure inside the container decreases. When the pressure drops to 100 millibars, about 2.1% of oxygen gas will remain inside the package. And if it drops to 10 millibars, about 0.21% of oxygen will still remain. Even if the pressure is reduced further, a defined amount of oxygen will always be left inside the package.
Below is an overview of how a food product is packed using the vacuum packaging method.
Check out the video below to see how cooked corn is manually packed and vacuum-sealed.
Nitrogen flush packaging is a type of modified atmosphere packaging (MAP). It is a way of keeping food products fresh by substituting the oxygen gas inside the containers with nitrogen gas. It involves sealing a package after flushing it with nitrogen gas to slow down the decay process by preventing oxidation and microbe growth.
Aside from being a safe inert gas, nitrogen is abundant in the atmosphere so nitrogen flush packaging is a cost-effective way of protecting your food products from spoilage. The amount of nitrogen necessary to keep a food product fresh will depend on various factors including the type of food and its rate of decay. So packagers should know how to use nitrogen flushing properly.
The working principle of nitrogen flush packaging is described below.
Below is a video on how milk powder is sealed using nitrogen flushing.
The question on which of these two food preservation methods is more effective will depend on the type of products being packaged. The table below presents a comparison between vacuum packaging and nitrogen flush packaging based on 4 factors.
|First header||Vacuum Packaging||Nitrogen Flush Packaging|
|Working Principle||Sucks out all of the air inside the filled package||Displaces the oxygen inside the package with nitrogen gas|
|Versatility||“One size fits all” method||More versatile|
|Only relies on air removal||Can be modified based on the product type (you can adjust the amount of nitrogen to give the product its optimal shelf life)|
|Product Presentation||The packaging material will collapse, forming itself around the product||Since it replaces the oxygen with nitrogen, the package maintains its shape|
|Distorts/deforms the product’s appearance||Protects the package from collapsing to prevent damage especially to delicate products|
|The product might lose its important characteristics|
|Ease of Quality Control||The absence of any gas inside the sealed package makes leak testing hard to do and needs to be done manually||You can constantly monitor the package’s gas content during the sealing process|
|Quality control is less straightforward||You can detect any leakage after sealing to ensure the seal’s integrity|
Though vacuum packaging is able to remove oxygen from the package to stop oxidation from happening to extend a product’s shelf life, a certain amount of oxygen will always remain inside the package. Nitrogen flush packaging is a more effective way to not only keep your food fresh but also to protect delicate food products from transportation damages. Hopefully, this short guide was able to help you choose the right packaging method for your application. You can also find ideal can packaging machines here in LPE.