NITROGEN GENERATOR FOR FOOD PACKAGING

The Modified Atmosphere Packaging (MAP) technology basically indicates the packaging of foodstuffs in a different atmosphere from the natural one to maintain their freshness and extend their shelf-life. To lengthen the life of a food, obviously, it is essential to block or slow down all those chemical and biological mechanisms that determine its deterioration.
Even in those cases where modified atmosphere packaging does not guarantee a significant shelf-life extension, the technique may allow a better presentation; e.g., a portion of fresh meat may appear with a more appreciated colour, a dairy product may show up less greased on the surface, and ham may offer slices well separated from each other. In any case, the use of modified atmospheres is not a means of rehabilitation or qualitative improvement of a poor food product but, rather, a technological support operation that only, together with other interventions (such as refrigeration, hygienic control, etc.), can achieve the desired effects.

A proper application of the modified atmosphere packaging technique should consider the nature and the characteristics of the product to be packaged, in particular:

• Perishability of the food in the air, which is the main cause of its deterioration (microbiological, oxidative, enzymatic, etc.)
• Solubility of Carbon Dioxide in the food at different temperatures and related organoleptic variations
• Microflora behaviour in the atmosphere, to avoid proliferation of anaerobic microorganisms or of an undesired selection of the typical microflora
• Permeability of packaging materials to the gas, taking in account the storage temperature and the total surface
• Tightness of the package, i.e., the absence of micro-holes and/or closure defects
• Effectiveness of the air replacement operation, i.e., choosing the most suitable type of packaging machine, gas supply and mixing system
• Accuracy of the atmosphere composition as well as of the Oxygen residual measurement after packaging.

All technical gases companies supply food-grade gases in compressed gas cylinders or bundles of cylinders at 200 bar-g, or in cryogenic tanks. The choice of the type of supply comes from consumption and logistics of the user company, so it is a technical-economical choice. Additionally, many gas suppliers have recently developed dedicated food-grade gas mixtures under tradenames, which they deliver already pre-mixed to the customers.

To choose the most suitable supply of Nitrogen or of food-grade gas mixtures is sometimes problematic, and it can be, in case of a wrong decision, very expensive. Traditional supply methods involve rental, refill and delivery, environmental levy and order processing charges, in addition to several other problematic issues, such as supply monitoring, payments management, storage handling and maintenance, etc. If, moreover, the price of gas and supplier’s rates continually increase while the environmental impact of truck-based deliveries gains significance, the cost of traditional supply becomes extremely high and difficult to budget.

By means of Pressure Swing Adsorption (PSA) technology, NITROGAS® NG Nitrogen generators for food packaging produce Nitrogen from industrial air class 1.4.1, ISO 8573.1-2010 standard. Dry and clean air from a standard industrial compressor and an air treatment system is essentially “sieved” to remove Oxygen and other trace gases, while Nitrogen passes through to the application. By using specially selected molecular sieves (CMS), Gasgen Nitrogen generators for food packaging make possible to obtain extremely pure Nitrogen (up to 99.999%) with a very moderate air consumption.

Not-cryogenic air separation is a well-known process, but the design and control features applied on NITROGAS® NG Nitrogen generators help to maximise gas output and reduce air consumption, achieving the highest levels of efficiency. As a result, choosing an on-site Nitrogen generator rather than relying on an external traditional supply can lead up to 90% costs reduction: the investment’s payback period is typically between 6 and 24 months.