How to Choose a MAP Sealing Machine: A Comprehensive Guide for Food Technologists

Modified Atmosphere Packaging (MAP) technology has been actively used for over 15 years in meat processing, fish processing, dairy enterprises, culinary shops, and restaurants. MAP equipment can extend the shelf life of perishable products by 3–4 times. However, choosing the right machine is not a simple task. This article breaks down the key criteria for selecting MAP packaging equipment.

  Main Types of MAP Equipment

Depending on the scale of production, product range, and type of packaging used, MAP equipment is divided into several main groups:

 Tray Sealers – for Pre-formed Trays

Working principle: A pre-formed plastic container with the product is placed into a sealed chamber, air is evacuated, the gas mixture is injected according to a set recipe, and then the tray is sealed with a barrier film.

Best suited for: Medium-volume production facilities with a wide product range that requires frequent format changes. Tray sealers are ideal for ready meals, salads, meat cuts, and semi-finished products in trays.

Advantages:

- Fast changeover between different tray types (as little as 10 minutes)

- Compact footprint – takes 20–30% less space than thermoformers

- Works with a wide range of materials – from rPET to paper-based trays

- Easy sanitation and cleaning

Output: Up to 40–80 packages per minute, optimal for volumes under 2,000 trays per day.

 Thermoformers – Forming, Filling, and Sealing

Working principle: A barrier film is unrolled from a reel, heated, and formed into trays. The product is placed in (manually or automatically), then, after evacuation and gas flushing, the trays are sealed with a top film and cut out along the contour.

Best suited for: Large-scale production with a stable product range and high output volumes. Thermoformers are especially efficient for sausages, cheeses, meat and fish semi-finished products in uniform packaging.

Advantages:

- Speed up to 80–120 packages per minute

- Lower packaging material consumption

- Precise control of residual oxygen (less than 1%)

Disadvantages:

- More expensive investment

- Significantly larger footprint

- Complex and time-consuming changeover when switching formats

 Chamber (Vacuum) Machines

A classic solution for smaller production facilities. The product is placed in a pre-formed bag or tray, packages are placed inside a chamber where air is evacuated, then pressure is equalized using gas, after which the bags are sealed.

Best suited for: Small enterprises, restaurants, and laboratories. Output: up to 2–3 cycles per minute.

 Gastronorm Container Systems (e.g., INOVAC-type)

Specialized solutions for restaurants, culinary shops, and central kitchens. Stainless steel gastronorm containers are reusable and can be used both for cooking and for storage. The machine evacuates the container, injects the gas mixture, and prints a label with batch parameters.

 How to Choose the Right Machine: A Step-by-Step Guide

 Step 1. Assess Your Product Range and Batch Sizes

The key question: how often do your products and packaging types change?

 If you produce...  Recommended machine type

 Many different SKUs with frequent format changes  Tray sealer

 Uniform products in large batches  Thermoformer

 Small batches, experimental recipes  Chamber machine

 Products for restaurants and catering  Gastronorm system

Tray sealers offer maximum flexibility: format changeover takes just minutes without tools. Thermoformers, on the other hand, perform best when your line runs one product continuously for days.

 Step 2. Determine the Required Residual Oxygen Level

Different products require different oxygen levels in the package. For example, red meat requires 70–80% oxygen to maintain its bright red color. For ready meals and cheeses, on the other hand, oxygen should be minimized.

The gas delivery method is critical:

- Vacuum re-injection (used in chamber machines, tray sealers, and thermoformers): achieves residual oxygen below 1%.

- Gas flushing (gas exchange): displaces air with a gas stream, resulting in residual oxygen around 3%.

For oxidation-sensitive products, choose machines with vacuum re-injection capability.

 Step 3. Calculate the Required Output

Output capacity depends directly on the machine type:

- Thermoformers: 80–120 packages/min, up to 15–20 cycles/min

- Tray sealers: 40–80 packages/min

- Chamber machines: 2–3 cycles/min

Estimate your daily production volume and choose a machine with 15–20% extra capacity for future growth.

 Step 4. Consider Packaging Material Requirements

Not all materials are equally compatible with all machine types:

Barrier films and trays must provide:

- Complete hermetic seal

- Chemical inertness

- High barrier properties

- Food-grade approvals

Almost 95% of barrier films are imported. Ensure your film supplier confirms compatibility with the chosen machine.

Pay special attention to seam strength – this is where packages most often begin to leak gas, triggering oxidative processes.

 Step 5. Evaluate Your Facility Space and Conditions

Tray sealers have a significantly smaller footprint. If your production floor is limited – this is your choice. Thermoformers require more space for film unwinding, heating systems, vacuum chambers, cutting stations, and extended conveyors.

 Step 6. Consider Sanitary Requirements

In food production, hygienic machine design is critical. Tray sealers have more open and accessible components for cleaning and inspection. In thermoformers, internal components are harder to access, which may increase sanitation time, especially when switching between allergenic products.

  Important Selection Nuances

 Gas Consumption

Different machine types have different gas consumption rates. For budget planning and gas cylinder connections, consider:

- Vacuum re-injection: 1 volume of gas per 1 volume of chamber

- Gas flushing: 3–8 volumes of gas per 1 volume of package

 Gas Mixing Systems

Modern machines must allow recipe programming for each product. Different products require fundamentally different gas mixtures:

 Product category  Recommended gas mixture

 Fresh red meat  Up to 80% O₂ (to preserve color) + CO₂

 Fresh poultry  30% CO₂ + 70% N₂

 Ready meals and seafood  30% O₂ / 40% CO₂ / 30% N₂

 Cheeses  Up to 100% CO₂

 Smoked meats  30–40% CO₂ + 60–70% N₂

 Bakery products  50% CO₂ + 50% N₂ (or 100% N₂ for cream products)

Look for a machine with an intuitive interface that allows storing dozens of recipes and quick switching between them.

 UV Treatment

Additional aseptic treatment with an ultraviolet lamp helps reduce the natural contamination level of the product before packaging, especially important for poultry and fish.

 Practical Recommendations by Application

For meat processing plants with a wide range of sausages and delicatessen products – tray sealers are optimal, providing quick changeover between different trays and slice formats.

For large poultry processors packaging dozens of tons of chilled poultry and semi-finished products daily – high-speed thermoformers are the better choice.

For restaurant holdings and central kitchens – a gastronorm container system allows using the same container for cooking, storage, and transport, with full tracking of date and time of packaging.

For small fish or meat processing workshops with volumes up to 50 packages per day – a compact chamber machine is sufficient; it is easy to maintain and does not require large investments.

  Shelf Life Expectations with MAP Equipment

Properly selected equipment, combined with quality barrier materials and optimal gas mixtures, can significantly extend shelf life:

 Raw red meat  5–8 days

 Fresh poultry  10–21 days

 Raw fish and seafood  4–6 days

 Fresh pasta  3–4 weeks

 Bakery products  4–12 weeks

 Dairy products  2–12 weeks

 Prepared meat dishes  3–7 weeks

 Cooked poultry  7–21 days

 Cooked fish and seafood  7–21 days

 Salami (processed meats)  4–8 months

Conclusion

Choosing a MAP sealing machine is a strategic decision that will determine the efficiency of your production for years to come. Evaluate your product range, batch sizes, required oxygen levels, available floor space, and budget. Consult with experts and gas suppliers – developing the optimal gas mixture recipe for each specific product is complex and requires laboratory research.

A properly selected machine, combined with high-quality barrier materials and the optimal gas mixture, will allow you to:

- Extend shelf life by 3–4 times

- Reduce product losses

- Expand your distribution geography

- Maintain product quality and safety

- Meet consumer expectations for freshness and appearance

The technology is approved by food safety authorities worldwide, and the market for MAP equipment continues to grow, with annual sales increases of approximately 40% in many regions.