Food suppliers are always seeking ways to extend shelf life. Improved shelf life allows manufacturers to extend their geographical reach and allows product to remain in stores and consumer's homes longer. Modified Atmosphere Packaging (MAP) is a technique commonly used in the food processing industry to extend shelf life. The MAP process involves displacing the air inside a package with a protective gas to keep oxygen at controlled levels (less than 2 percent). Too much oxygen and moisture in a package often leads to bacterial growth and oxidation resulting in spoilage, inconsistent flavors, poor product quality, and shortened shelf life. Nitrogen is frequently used as a protective gas because of its dry, inert qualities.
Sources of nitrogen
Nitrogen can be obtained from outside suppliers in the form of high pressure tanks, dewars, or bulk liquid supply. Nitrogen can also be produced on-site using standard compressed air with an in-house nitrogen generator. An in-house generator separates nitrogen and oxygen from the air, and can often be the most efficient and economical method of supplying nitrogen for MAP applications.
Disadvantages of a delivered nitrogen supply
Relying on outside vendors can pose several challenges including uncontrollable price increases, contract negotiations, tank rental fees, adherence to OSHA requirements, hazardous material fees, delivery surcharges, and local and state taxes. Problems such as scheduling conflicts, delivery delays, and lengthy procurement processes can slow down operations.
This all adds up to extra administrative work and higher operational costs. The delivery approach also doesn’t fit the trend toward lean production techniques and developing fewer, more efficient supply chains.
Precautions must also be taken when handling and storing high pressure cylinders. A dangerous situation can be created if a cylinder is dropped and a valve is broken off, potentially causing the cylinder to become a projectile.
Operational benefits of generating nitrogen on-site
Generating your own supply of nitrogen in-house eliminates the challenges associated with outside vendors and ensures long-term cost stability. Generating nitrogen in-house is also good for the environment and represents a sustainable approach to supplying the gas. Producing nitrogen off site at fractional distillation plants and transporting it to end users is energy intensive and can result in large amounts of CO2 emissions.
Easy to operate
A Parker nitrogen generator, for example, produces a continuous supply of high purity nitrogen within minutes of start up. Installation consists of simply connecting the inlet port of the unit to a standard compressed air line and connecting the outlet to your nitrogen line.
Improve quality, reduce costs
Final product quality is the most important aspect of food manufacturing. Customers expect freshness and consistent taste every time they open a new package of food. Bacteria growth in the final package reduces shelf life and ultimately leads to an unsatisfied customer. Packaging with dry nitrogen will solve these issues and provide a better customer experience. What’s more, using an on-site nitrogen gas generator not only improves operational efficiency, it also reduces overall costs—a rare combination.
Read this marketing application on using nitrogen for modified atmosphere packaging.
This post was contributed by Judy Silva, Gas Generation Technology Blog Team Member, Parker Hannifin.