Protective atmosphere packaging (MAP): principles, gases, equipment and best practices
Mise sous Atmosphère Protectrice (MAP) – also known as Modified Atmosphere Packaging – is a preservation technique that involves replacing the air (and therefore oxygen) in a tray with a specific gas mixture, before hermetically sealing. The aim is to extend the best-before date while preserving the product’s appearance, texture and quality.
Remember: MAP is not a vacuum pack. Here, the gas also acts as a cushion to preserve product volume and presentation.
Contents
- Definition and principle
- Operating cycle
- Advantages: MAP vs. conventional sealing
- Choosing the right gas mix
- Essential equipment and consumables
- Common mistakes (and how to avoid them)
- FAQ + Schema
- Learn more
Definition and principle
MAP involves replacing the air in a tray with a gas mixture (often Nitrogen (N₂) + CO₂, sometimes O₂ depending on the product), then sealing the tray with a suitable film.
Gases used (fast role)
- N₂ (Nitrogen): neutral gas, limits oxidation, “cushion” effect.
- CO₂: bacteriostatic effect (inhibits microbial growth).
- O₂: color maintenance (e.g. red meats according to specifications).
What MAP really changes
- Less oxygen → less oxidation.
- Atmosphere mastered → DLC increased.
- Uncompressed product → better presentation.
Operating cycle (6 stages)
A MAP machine generally performs the following cycle:
- Closing the bell
- Vacuum: extraction of air (oxygen)
- Gas injection: introducing the protective mixture
- Sealing: welding the film to the tray
- Gradual atmosphere release
- Reopening
Key benefits (MAP vs. conventional sealing)
| Profit | In concrete terms |
|---|---|
| Extended CSD | Often 3 to 5× longer, depending on product and process. |
| Product quality | Preserves textures and presentation (unlike vacuum-packed bags, which can compress). |
| Health and safety | Slows down aerobic bacteria and molds responsible for fermentation. |
| Logistics | Facilitates delivery further afield and reduces waste. |
Gas mixture guide (by product)
The right mix depends on the product, its sensitivity to oxidation, the target BBD and presentation constraints.
Dry products (chips, cookies)
100% N₂: prevents rancidity and protects mechanically (“cushion” effect).
Prepared dishes, pasta, cold cuts
N₂ + CO₂: CO₂ inhibits microbial growth.
Red meats
Blend richer in O₂ to maintain bright red color (depending on configuration and machine constraints).
Fresh plants
Minimum-breathing atmosphere (calibrated according to product).
💡 Conseil “pro
MAP is more than just “injecting gas”. For stable results, align recipe + target BBD + barrier consumables + machine settings.
Essential equipment and consumables
Equipment
- MAP-equipped heat sealer (bell + high-performance pump).
- Suitable gas pressure regulator to connect the cylinder.
- Hygienic design (food-grade stainless steel, easy to clean).
Barrier” consumables
- Barrier trays: limit gas diffusion through the plastic.
- High-barrier lidding films: preserve the injected mixture over time.
Common mistakes (and how to avoid them)
Classic traps
- Use non-barrier trays/films: gas escapes.
- Choose the mixture “at random”: unstable results in terms of CSD and rendering.
- Approximate machine settings: inconsistent residual O₂ rate.
- Do not test under real-life conditions (cold, transport, delays).
The simple way to secure
- Define the product and the target BBD.
- Validate the tray + film combination (high barrier).
- Define the mix with a gas partner and/or your quality approach.
- Test 2-3 settings (vacuum/gas/welding time) and check repeatability.
FAQ (SEO optimized)
Does MAP replace sous-vide?
No. MAP is particularly suitable when presentation needs to remain intact, as the gas preserves volume. Sous-vide bags are still very effective at blocking oxygen, but can compress certain products.
Why do we need “barrier” consumables?
Because some plastics let oxygen and CO₂ diffuse: without a barrier, the injected mixture escapes, and MAP’s benefits diminish.
Which products benefit most from MAP?
Products sensitive to oxidation and/or microbial growth, as well as those requiring impeccable presentation (ready-made meals, cold meats, meats, fragile products).
Learn more
Would you like to know if MAP is right for your products, your trays and your output? We can guide you towards the most appropriate solution (technology, consumables, settings, best practices).