Glossary
What is Nitrogen flushing?
Also called: nitrogen gas flushing, gas flushing, N2 flushing
Nitrogen flushing replaces the air in a food pack with nitrogen just before sealing. This removes oxygen to slow rancidity and cushions fragile products.
Nitrogen flushing is a form of modified atmosphere packaging (MAP). Nitrogen is a comparatively inert gas. When it displaces oxygen from the headspace of a pack, it slows the oxidative rancidity that makes fats in snacks, nuts and similar foods taste stale. The gas also acts as a filler, so the pack does not collapse and fragile products such as potato chips are protected from crushing.
On a VFFS bagger, nitrogen is fed into the bag through the forming tube as the top seal is made. Many plants make their own supply with on-demand nitrogen generators. Flushing reduces oxygen, but it does not make a food safe on its own. Low-oxygen packs still need proper temperature control and hygiene.