How nitrogen displaces oxygen in packaged food to extend shelf life 2-5x. Used in snacks, coffee, fresh produce, meat, and dairy packaging.
In modified atmosphere packaging (MAP), the air inside a package is replaced with a controlled gas mixture — typically 99.0-99.9% nitrogen. By removing oxygen, MAP prevents oxidation (rancidity in oils/fats), slows microbial growth, and maintains product texture and color.
Common MAP applications:
| Product | Snacks/Nuts | Coffee | Fresh Produce | Meat/Dairy |
|---|---|---|---|---|
| N2 Purity | 99.0-99.5% | 99.5-99.9% | 99.0-99.5% | 99.5% |
| Residual O2 | <2% | <0.5% | 3-5% | <1% |
| Flow/Line | 10-20 Nm3/h | 8-15 Nm3/h | 15-30 Nm3/h | 10-20 Nm3/h |
Food-grade nitrogen requires stainless steel 304/316L construction on all wetted parts. Standard industrial PSA generators meet this requirement — no special food certification needed for the gas itself.
Scenario: Single MAP line consuming 30 Nm3/h, 16 hours/day, 300 days/year.
Bottled N2: 30 Nm3/h x 4,800 hrs x $0.50/Nm3 = $72,000/year
On-site PSA: 30 Nm3/h x 4,800 hrs x $0.18/Nm3 = $25,920/year
Saving: $46,080/year — station payback in 7-8 months