Introduction

Fresh food is one of the most demanding categories to package. Meat, poultry, seafood, cheese, bakery products, salads and ready meals spoil quickly when exposed to oxygen, microorganisms and moisture. For producers, short shelf life limits how far products can travel, how long they can stay on shelves and how much is wasted. For retailers and consumers, it means frequent deliveries and discarded food.

Packaging technology can extend shelf life significantly while keeping food fresh, attractive and safe. The three main approaches are modified atmosphere packaging (MAP), vacuum packaging and vacuum skin packaging, delivered by machines such as MAP tray sealers, thermoforming machines and rotary vacuum packers.

Research has shown the potential. Studies on bakery products have found that MAP with carbon dioxide and nitrogen mixtures can significantly extend shelf life, and industry sources report extensions of two to several times for some meat and bakery products, depending on product, gas mix, temperature and hygiene. Results vary widely, so shelf life should always be validated for each product.

This article explains how fresh food packaging machines work, which products they suit and how to choose and use them effectively.

How packaging extends shelf life

Fresh food deteriorates mainly through:

• Microbial growth: bacteria, yeasts and moulds.
• Oxidation: changes in colour, flavour and fat quality.
• Moisture loss or gain: drying out or becoming soggy.
• Physical damage: crushing and leaks.

Packaging slows these processes by controlling the atmosphere around the product, providing a barrier to oxygen and moisture, and protecting the product physically. Packaging is not a substitute for good hygiene and refrigeration. It works alongside them.

Modified atmosphere packaging (MAP)

How it works

MAP replaces the air inside a pack with a protective gas mixture, usually combinations of:

• Carbon dioxide (CO₂): slows the growth of many bacteria and moulds.
• Nitrogen (N₂): an inert filler gas that prevents pack collapse and displaces oxygen.
• Oxygen (O₂): used at high levels for some red meats to maintain red colour, and kept low or absent for most other products.

The pack is then sealed with a barrier lidding film.

Typical gas mixtures

Gas mixtures vary by product. As general examples:

• Red meat: high oxygen with carbon dioxide.
• Poultry and seafood: carbon dioxide with nitrogen.
• Bakery: carbon dioxide with nitrogen, for example around 30% CO₂ and 70% N₂ in some studies.
• Cheese: carbon dioxide and nitrogen.
• Salads: low oxygen levels balanced for produce respiration.

Gas mixtures should be developed and validated with food technologists for each product.

MAP tray sealers

Tray sealers seal preformed trays with lidding film. The process:

1. Filled trays are placed on the infeed conveyor.
2. Trays move into the sealing station.
3. Air is evacuated and replaced with the gas mixture.
4. The lidding film is heat-sealed to the tray rim and cut.
5. Sealed trays leave the machine.

Typical specifications

The MAP tray sealer range Dsigngo Group supplies includes four models:

• AM-550 compact tray sealer: mould 550 × 280 × 80 mm, 1,200 to 1,500 trays per hour.
• AM-650 automatic tray sealer: mould 850 × 320 × 80 mm, 1,500 to 1,800 trays per hour.
• AM-750 tray sealer: mould 750 × 280 × 80 mm, 1,500 to 1,800 trays per hour.
• AM-850 high-speed tray sealer: mould 850 × 880 × 100 mm, 2,500 to 2,800 trays per hour.

The machines use PLC control with touch screens and can work with laminated, aluminium foil and co-extruded films. Moulds can be customised to specific tray designs.

Best for

Fresh meat and poultry, seafood, ready meals, cut fruit, salads, cheese, bakery and desserts in trays.

Vacuum packaging

How it works

Vacuum packaging removes air from the pack before sealing. Without oxygen, many spoilage bacteria grow more slowly and oxidation is reduced. The pack also becomes tight, reducing space and protecting the product.

Rotary vacuum packaging machines

Rotary vacuum machines automate vacuum packing for premade pouches. Pouches are picked, opened, filled and then sealed inside vacuum chambers. The range includes eight models, from high-speed machines for small pouches (up to about 150 bags per minute) to larger machines handling up to 2.5 kg.

Best for

Cooked and cured meats, sausages, cheese, pickles, ready-to-eat foods, rice products and dried fruits.

Thermoforming

How it works

Thermoforming machines create packs from two rolls of film:

1. The bottom film is heated and formed into cavities using moulds.
2. Products are loaded into the cavities, by hand or automatically.
3. Air is removed and, if required, replaced with gas.
4. The top film is sealed over the cavities.
5. Packs are cut apart and discharged.

Pack types

• Vacuum packs: tight packs for meats and cheese.
• MAP packs: gas-filled packs in formed trays.
• Vacuum skin packs: the top film shrinks tightly around the product like a second skin, showing it attractively and holding it in place.

Typical specifications

The thermoforming range includes three models:

• 420S/520S thermoforming vacuum packaging machine: upper film around 398 mm wide, 4 to 6 cycles per minute.
• 420Y/520Y double-sided stretch vacuum packaging machine: for stretch vacuum packs.
• 520DLSM full-automatic thermoforming line: wider film, around 3 to 4 cycles per minute, for larger operations.

Machines are built with stainless steel guarding, touch screen control, safety sensors on doors and automatic stopping when guards are opened. Output depends on the number of packs per cycle, which depends on mould design.

Best for

Meat, sausages, seafood, cheese, dates, biscuits, sauces and non-food items such as medical devices and tools.

Choosing between MAP, vacuum and thermoforming

Consider product type, shelf life target, pack appearance, volume and budget.

Other machines in fresh food lines

Fresh food packaging lines often include supporting equipment:

• Cup filling and sealing machines for yoghurt, curd, desserts and sauces, sealing preformed cups with foil or film lids at up to about 60 cups per minute.
• Continuous band sealers for smaller producers sealing pouches by hand.
• Chamber vacuum packers for butchers, restaurants and small processors.
• Thermal shrink packers for tightening film around trays and bundles.
• Metal detectors and check weighers for final inspection.

Combining these with the main packaging machine creates a complete, efficient line that moves products from preparation to dispatch with minimal handling.

Materials and barrier properties

Fresh food packaging relies on barrier materials that limit oxygen and moisture transfer. Common materials include:

• Multi-layer films with barrier layers such as EVOH or PA.
• PET, PP and PE trays with suitable barrier properties.
• Aluminium foil laminates.

Sustainability is increasingly important. Mono-material barrier films and recyclable trays are developing, but they must be tested for barrier performance and sealing. Dsigngo Group can help clients evaluate materials and design packs that suit their machines and markets.

Food safety and hygiene

Fresh food packaging must be supported by strong hygiene:

• Cold chain: products must be chilled before packing and kept cold afterwards.
• Hygienic design: stainless steel construction, easy cleaning and washdown where suitable.
• Seal integrity: leak testing and seal inspection ensure the atmosphere is maintained.
• Gas checks: gas analysers verify the gas mixture in packs.
• Labelling: clear use-by dates and storage instructions.
• Food safety systems: HACCP and ISO 22000 procedures cover packing steps.

In Sri Lanka, food businesses must comply with the Food Act and its regulations, and exporters must meet the requirements of destination markets.

Shelf life testing

Any shelf life claim on a pack must be supported by evidence. A typical shelf life study includes:

1. Define the product and pack: recipe, packing method, gas mixture, materials and storage temperature.
2. Pack samples: under normal production conditions on the actual machine.
3. Store samples: at the intended temperature, and sometimes at slightly abusive temperatures to simulate real-world handling.
4. Test at intervals: microbiological counts, appearance, smell, taste, colour and gas levels in the pack.
5. Set the shelf life: with a safety margin before the point where quality or safety becomes unacceptable.
6. Review regularly: especially after changes in recipe, supplier, materials or process.

Food technologists and accredited laboratories can support this work. In Sri Lanka, universities, research institutes and private laboratories offer testing services.

Labelling fresh food packs

Fresh food packs carry important information:

• Product name and weight.
• Use-by date and storage instructions.
• Batch or lot number.
• Packaging statements such as “packaged in a protective atmosphere”, which is required in some markets for MAP products.
• Ingredients and allergens for processed products.
• Producer details.

Labels must stay readable in chilled and humid conditions, so suitable label materials and printers are needed. Dsigngo Group designs and prints labels and sleeves for fresh food packs.

Running costs

When comparing fresh food packaging methods, consider ongoing costs:

• Packaging materials: trays, lidding films, pouches or forming films.
• Gases: cylinders or gas mixers for MAP.
• Electricity: heating, vacuum pumps and motors.
• Compressed air.
• Maintenance: vacuum pump oil and filters, seal plates, knives and moulds.
• Labour: loading trays or pouches, and quality checks.

Thermoforming often reduces packaging costs at high volume because packs are formed from roll film. Tray sealers offer flexibility and attractive presentation with preformed trays. Vacuum pouches suit products that need compact, tight packs. A careful comparison of material costs per pack helps identify the most economical option for each product.

Benefits for Sri Lankan producers

Sri Lanka’s seafood, poultry, processed meat, bakery and ready-to-eat sectors serve local supermarkets, hotels and export markets. Fresh food packaging machines can help them:

• Reach supermarkets across the island with longer shelf life.
• Reduce waste and returns.
• Present products attractively in clear packs.
• Meet hotel and food service requirements for portion packs.
• Access export markets that require longer shelf life and strict packaging standards.

Seal quality and leak testing

The protective atmosphere or vacuum only works if the seal holds. Common causes of seal failure include:

• Product, grease or moisture on the seal area of trays or pouches.
• Incorrect sealing temperature, pressure or time.
• Worn or damaged sealing tools.
• Film and tray combinations that are not compatible.
• Wrinkles in the film.

Good practice includes keeping seal areas clean during filling, checking seals visually on every batch, carrying out regular leak tests (for example, using water-bath or vacuum-chamber testers) and measuring gas levels in sample packs with a gas analyser. Records of these checks support food safety systems and customer audits.

Automating tray loading

For many producers, loading products into trays or cavities remains manual, especially for meat cuts and ready meals. As volumes increase, automation options include:

• Conveyors that bring trays to loading stations at a steady pace.
• Multihead weighers that fill trays with portions of loose products such as diced meat, vegetables or seafood.
• Denesters that place empty trays on the conveyor automatically.
• Labelling systems after sealing.

Even partial automation, such as conveyor-fed loading stations and automatic tray denesting, can improve speed and hygiene by reducing handling.

Utilities and installation

Fresh food packaging machines need:

• Electrical supply, often three-phase for larger machines.
• Compressed air.
• Gas supply for MAP, from cylinders or on-site gas mixers or generators.
• Suitable chilled or controlled-temperature packing rooms.
• Drainage and washdown areas, depending on hygiene requirements.

Planning these early avoids delays during installation.

Fresh food packaging for export

Exporters of seafood, processed meats, bakery products and ready meals face longer supply chains, stricter regulations and demanding buyers. Packaging must:

• Maintain quality through longer transport and storage times.
• Meet the destination market’s food contact material rules.
• Carry correct labelling, including language, nutrition and origin information.
• Withstand freezing or chilled transport without seal failure.
• Support traceability with clear batch codes.

Vacuum packaging and thermoforming are common for frozen and chilled exports, while MAP is often used for chilled retail packs in shorter supply chains. Exporters should confirm requirements with buyers and regulators before investing.

Choosing the right size of machine

Fresh food producers range from small butchers and bakeries to large processors. Machine choice should match the scale:

• Small producers: semi-automatic tray sealers or chamber vacuum packers suit small volumes and many product types.
• Medium producers: automatic tray sealers such as compact MAP models, or rotary vacuum machines for pouches.
• Large producers: high-speed tray sealers and thermoforming lines with automatic loading and labelling.

Starting with the right scale avoids overspending while leaving room to grow. Many producers begin with a compact machine for their best-selling product and add capacity as demand grows, keeping trays and films consistent across machines.

Common mistakes

• Expecting packaging to fix poor hygiene or temperature control.
• Using standard films without suitable barrier properties.
• Not validating gas mixtures and shelf life.
• Contaminated seal areas causing leaks.
• Choosing a machine without considering tray or pouch supply locally.
• Underestimating gas supply needs and the cost of gas over a full year.

Illustrative example

The following example is illustrative and does not describe a real client.

A Sri Lankan poultry processor sells chicken portions on foam trays wrapped in cling film, with a short shelf life that limits distribution outside Colombo. The processor installs a MAP tray sealer with barrier trays and lidding film, using a gas mixture developed with food technologists. After shelf life testing confirms the new use-by period, products reach supermarkets further away, returns fall and packs look cleaner on shelf.

How Dsigngo Group can help

Dsigngo Group supplies MAP tray sealers, thermoforming machines and rotary vacuum packers, with trials, installation, training and support. Our packaging design and print teams create labels, sleeves and printed films that complement fresh food packs.

Frequently asked questions

How much does MAP extend shelf life?

It depends on the product, gas mixture, hygiene and temperature. Extensions vary widely, so shelf life must be tested for each product.

Do MAP machines need special gas?

Yes. Food-grade gases or gas mixers are used, with mixtures chosen for each product.

What is vacuum skin packaging?

A thermoforming or tray sealing method where the top film forms tightly around the product, holding it in place and presenting it attractively.

Can one tray sealer handle different trays?

Yes, with different moulds, which are customised to tray sizes.

Is refrigeration still needed?

Yes. MAP and vacuum packaging work together with refrigeration for perishable foods.

Conclusion

MAP tray sealers, thermoforming machines and vacuum packers help fresh food producers extend shelf life, reduce waste and present products attractively. Success depends on choosing the right method, materials and gas mixtures, combined with strong hygiene and cold chain control.

Dsigngo Group helps fresh food producers in Sri Lanka select and install the right packaging machines.

Ready to keep your products fresher for longer? Talk to Dsigngo Group.

Discuss Fresh Food Packaging

Sources

• International Institute of Refrigeration (FRIDOC), studies on modified atmosphere packaging for bakery products.
• Industry gas supplier information on MAP shelf life (vendor claims; verify for each product).
• Machine specifications from the machine catalogue supplied by Dsigngo Group.