People in the food manufacturing and packaging industries use gaseous nitrogen in many different ways. Nitrogen is often thought of as the industry standard for non-chemical preservation. It’s cheap and easy to get. Nitrogen is suitable for many different things, but it needs to be checked for purity and possible contaminants. Other testing plans should be used depending on how the product is used, how it is distributed, and how pure it needs to be safe.
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Oxygen can be used to make food.
Packagers and food manufacturers have to develop ways to keep nutrients safe and make sure their products are good. Because oxygen causes food to oxidize, this gas can help microorganisms grow. This cannot be good for packaged foods (Welt and Connaughton, 2017).
People who eat a lot of fatty meats, fish, vegetables, and ready-to-eat foods are more likely to get sick. A third of fresh food doesn’t get to people because it gets spoiled in the truck (Sengupta, 2017). Changing the packaging atmosphere can be a perfect way to ensure that products are safe for people to buy.
Many manufacturers change the atmosphere of the packaging to include more nitrogen to keep fresh foods fresher for longer (American Chemistry, 2010). If you want to keep your food safe, you can use nitrogen instead of oxygen or add extra gas. Increased nitrogen keeps the food fresh, protects the nutrients, and stops aerobic microbial growth.
The main problem with changing the atmosphere of packaging is that some foods need a small amount of oxygen to keep their color and texture (Welt and Connaughton, 2017). Red meat, for example, will turn a lousy color if it doesn’t get enough oxygen. Food manufacturers sometimes lower the purity of nitrogen in their food to make it more appealing.
Nitrogen is also used more and more often in the coffee and beer industries and meat and vegetables. Guinness, for example, is known for its foam made of nitrogen gas (Welt and Connaughton, 2017). Also, nitrogen-brewed coffee has become a lot of people’s favorite. Manufacturers who add nitrogen to their drinks must meet specific purity standards and ensure that the gas is not contaminated.
The Value of Pure Gas Testing
Nitrogen is an integral part of preserving, transporting, and quality control fresh food and drinks, so it must be checked often. Things like gas, particles, water, oil, and microorganisms can be damaged, making them less pure.
Each system needs a different way to be tested. Variables to think about include nitrogen cylinders vs. nitrogen generators, how old the system is, how the gas is distributed, and how the gas comes into contact with the product, among other things. Complete a risk assessment to make sure you know everything there is to know about your system and what it needs.
Cylinders and generators that use nitrogen
Those who work with nitrogen cylinders or generators can expect to get clean and dry nitrogen right from the source. If you’re a quality manager at Trace Analytics, you need to think about the distribution line as well. Smith says that testing for gas purity at the point of use is the best way to ensure that the pipes aren’t contaminating the pure gas.
Systems that don’t work well or have leaked can make gas less pure and add contaminants like volatile hydrocarbons, water, oil, or particles. Leaks can cause lower purity levels or contamination because they make a vacuum that lets in the air with oxygen, moisture, and hydrocarbons from the outside (Kandl, 2005). Filters and materials that aren’t working correctly can make things dirty.
Whether you use cylinders or a generator, you need to check the gas quality at different points in the system to ensure it doesn’t worsen down the line. A third-party, accredited lab can do a lot of testing on pure gas systems to confirm that the gas at the back of the diffusion line is as pure as when it came out of the cylinder or generator.
Anaerobes
Nitrogen can change the atmosphere of packaged foods, but it doesn’t stop the growth of anaerobic bacteria. Anaerobes are microorganisms that can grow even when there is not enough oxygen for them to do so. These microorganisms can be hazardous and need to be carefully protected against because they can cause recalls and make people sick.
People who don’t keep their Nitrogen systems clean could be at risk for anaerobes, which don’t need oxygen to grow. Obligate anaerobes can only succeed if there is no oxygen. Facultative anaerobes can use oxygen but don’t need it to grow, but they can’t (USDA, 2012). Listeria, E. coli, and Botulism are all examples of facultative bacteria.
A lot of food companies have recalled their products because of Listeria. Over 20 of them did so (FDA, 2018). At best, places can be costly, and at worst, they can shut down the whole business. Because Listeria can live in the air, it can make its way through the system and affect food if the proper precautions aren’t taken. The other dangerous anaerobes to look for are E. coli, C. botulinum, and C perfringens, which are all terrible for your body (USDA., 2012).
The process by which pure gas testing works
GC-MS-FID is a tool used by Trace Analytics, LLC, to check for gas purity and contamination. The three different pieces of equipment work together to get the best results. The Flame Ionization Detector looks for gas contaminants like TVHC, CO, CH4, CO2, and CO2. The Mass Spectrometer looks for ions by mass and can tell Oxygen, Nitrogen, Argon, and water from Oxygen, Nitrogen, Argon, and water.
The sample is compared to NIST-traceable gas standards to find out how pure the gas is. Smith says that manufacturers set purity goals based on how often their products are used. For example, some manufacturers might want nitrogen purity to be 99.0% pure, but others might be okay with lower purity.
Optical microscopy is used to look for particulates in the food. It determines how many particles there are, so this is important. This method lets you look at point-of-use filtration and see if there are problems with things that come after the filter, like rust, metal shavings, o-ring materials, solder, and Teflon tape.
To properly test for anaerobic contamination, people use the Pinocchio Super II Impaction Sampler and blood agar contact plate media to take samples of their food. You open a GasPak in an air-tight container to ensure only anaerobic microbes can grow there. An accredited microbiology lab can then incubate it to see if the gas has been contaminated. If a company thinks there might be Listeria or E. coli in their food, special plates can be used that will show if the food is safe or not.
