Temp log
Frozen storage −18°C or colderChilled foods 0 to 5°C typicalBananas avoid below ~13°CDanger zone 5–60°CIce cream hardening −25°C to −30°CLeafy greens 0–2°C, high humidityChocolate around 15–18°C, dryLive seafood species-specificBlast freezer air −30°C to −40°CCured vanilla cool, dry, sealedFrozen storage −18°C or colderChilled foods 0 to 5°C typicalBananas avoid below ~13°CDanger zone 5–60°CIce cream hardening −25°C to −30°CLeafy greens 0–2°C, high humidityChocolate around 15–18°C, dryLive seafood species-specificBlast freezer air −30°C to −40°CCured vanilla cool, dry, sealed

Packaging

Food tech in packaging: modified atmosphere and active packaging for fresh produce

Fresh produce keeps breathing after harvest. Modified atmosphere packs, ethylene absorbers, antimicrobial films and freshness indicators all aim to slow that clock, but only inside a working cold chain.

By Editorial desk · · 3 min read

MAP principle
Lower oxygen, higher CO2 slows respiration
Active packaging
Ethylene absorbers, oxygen scavengers, moisture control, antimicrobials
Limit
Packaging extends shelf life only with correct temperature

Fresh fruit and vegetables are alive after harvest. They continue to respire, using oxygen and releasing carbon dioxide, heat and water. Many also produce ethylene, a plant hormone that speeds ripening. Packaging technology can slow these processes and extend shelf life. This article looks at modified atmosphere packaging (MAP) and active packaging for fresh produce.

Modified atmosphere packaging

MAP changes the gas mix around the product. For fresh produce, the usual aim is lower oxygen and higher carbon dioxide than air. This slows respiration and ripening, delays browning and can reduce microbial growth.

There are two main approaches:

  • Passive MAP: the produce's own respiration changes the atmosphere inside a pack with a film of chosen permeability. Over time, the pack reaches an equilibrium.
  • Active MAP: the pack is flushed with a gas mixture before sealing.

The film is critical. Fresh produce needs some oxygen to avoid anaerobic respiration, which produces off-odours and can create food safety concerns. Films with micro-perforations or specific permeability allow the right balance. Different produce types need different films: salad leaves, berries, mushrooms and broccoli all behave differently.

Active packaging

Active packaging includes components that interact with the product or atmosphere:

Ethylene absorbers. Sachets or films containing materials such as potassium permanganate or certain minerals remove ethylene, slowing ripening in sensitive produce.

Oxygen scavengers. Used more in other foods, but sometimes relevant for processed produce.

Moisture control. Absorbent pads and humidity regulators prevent condensation and mould while keeping produce from drying out.

Antimicrobial packaging. Films or coatings with natural antimicrobial agents, such as some essential oils, are being researched and used in some applications, subject to regulatory approval.

Edible coatings. Thin coatings applied to fruit reduce water loss and gas exchange. Some are based on plant lipids or polysaccharides.

Intelligent packaging

Intelligent packaging monitors condition rather than changing it:

  • Time-temperature indicators change colour based on accumulated temperature exposure.
  • Freshness indicators react to gases produced during spoilage.
  • Ripeness indicators react to ethylene or other volatiles.
  • Digital tags link packs to traceability data.

These tools can help retailers rotate stock and help consumers judge freshness, though adoption is still limited by cost.

Temperature is still the foundation

Packaging only works within the right temperature range. MAP films are designed for specific temperatures. If produce warms, respiration speeds up, oxygen inside the pack may drop too far, and quality can fall quickly. Condensation from temperature changes can encourage mould.

Pre-cooling produce quickly after harvest is one of the most important steps. Methods include forced-air cooling, hydrocooling and vacuum cooling, depending on the produce. After that, a steady cold chain keeps packaging working as designed.

Sustainability questions

Packaging for fresh produce faces pressure to reduce plastic use. At the same time, packaging can reduce food waste, which also has environmental impact. Producers are exploring:

  1. mono-material films that can be recycled;
  2. paper-based packaging with barrier coatings;
  3. compostable films for some uses;
  4. packaging only where it clearly reduces waste.

Life-cycle thinking helps: the best packaging choice depends on how much waste it prevents compared with its own impact.

Matching pack to supply chain length

The right pack depends on how far the product travels. Produce sold close to where it is grown may need little more than a ventilated punnet. Produce shipped by sea for weeks may need controlled atmosphere containers, MAP liners and ethylene control. Packers should design packaging for the actual route and time to shelf, not a generic specification.

What growers and packers should consider

  • Match film and atmosphere to the specific produce.
  • Pre-cool produce before packing.
  • Control temperature through the supply chain.
  • Test shelf life under realistic conditions.
  • Check regulatory approvals for active components.
  • Evaluate recyclability in target markets.

MAP and active packaging are powerful food technology tools. Used with a reliable cold chain, they can keep produce fresh longer and reduce waste.

Key figures above are general reference points, not regulatory limits.