Key Features of MAP Bags
| Feature | Description |
|---|---|
| High Gas Barrier | Prevents gas exchange; retains modified atmosphere inside the bag. |
| Multi-Layer Structure | Commonly 3–9 layers (e.g., PET/NY/PE, PET/EVOH/PE) for strength and barrier. |
| Sealable Surface | Inner layer (usually PE or CPP) allows for heat sealing. |
| Puncture Resistance | Especially important for meat, bones, and sharp items. |
| Custom Gas Permeability | For fresh-cut produce (O₂ and CO₂ exchange), micro-perforation optional. |
Common Material Structures
| Structure | Application Example | Notes |
|---|---|---|
| PET/PE | Basic structure for bakery, produce | Moderate barrier |
| PET/PA/PE | Fresh meat, seafood | Puncture resistance |
| PET/EVOH/PE | High barrier for cheese, cooked meats | Excellent gas barrier |
| NY/PE | Frozen or chilled foods | Flexible, strong |
| PET/AL/PE | Light- and gas-sensitive foods | Maximum barrier (light/gas) |
Applications by Food Type
| Food Type | Typical Gas Mixture | Packaging Style |
|---|---|---|
| Red Meat | 70–80% O₂ + 20–30% CO₂ | Vacuum skin or tray bag |
| Poultry | 30% CO₂ + 70% N₂ | Thermoformed tray or pouch |
| Seafood | 40% CO₂ + 60% N₂ | Vacuum + MAP bag |
| Cheese | 30% CO₂ + 70% N₂ | Three-side seal bag |
| Fresh Produce | Low O₂ + High N₂ / Micro-perforated | Bag with vent or MAP pouch |
| Bakery | 100% N₂ | Gusset pouch or flowpack |
| Ready Meals | 30–50% CO₂ + N₂ | Tray with lidding film |