The Ultimate Guide to Modified Atmosphere Packaging (MAP) for Meat Products

Table of Contents

Introduction

Modified Atmosphere Packaging (MAP) has revolutionized the way we store and preserve meat products. By altering the atmospheric composition inside the packaging, MAP extends the shelf life of meats while maintaining their quality, taste, and safety. This guide provides insights into the best MAP gas mixtures for different types of meats – fresh and processed, including beef, lamb, pork, chicken, and turkey. We’ll also delve into how smoking, product types like sausages, meatballs, and minced meat, and other factors like humidity and pressure affect MAP efficacy.

MAP for Fresh Meats

Beef: For fresh beef, a high oxygen mix (around 80%/20%; O₂/ CO₂) is ideal. Oxygen ensures the meat retains its attractive red colour, while CO₂ inhibits microbial growth.
Lamb and Pork: Similar to beef, lamb, and fresh pork benefit from a 70/30 O₂/CO₂ mix. This ratio maintains the fresh, red appearance of the meat while preventing bacterial growth.
Chicken and Turkey: Poultry is usually packaged in a lower oxygen environment (about 30% O₂ and 70% CO₂ or N₂) to prevent the growth of spoilage organisms and maintain colour and freshness.

MAP for Processed Meats

Processed meats, including sausages, meatballs, patties, and extended minced meat, are best preserved in a lower-oxygen environment to prevent oxidation and rancidity. A typical mix is 70% N₂/30% CO₂. Nitrogen is inert and prevents oxidative spoilage, while CO₂ inhibits microbial growth. Smoking doesn’t significantly change the required gas mix, but smoked meats may have a slightly reduced need for oxygen due to the preservative effects of the smoking process.

Special Considerations

Spice Packs and Susceptibility to Oxidation: Spices rich in unsaturated fats (like paprika) can increase susceptibility to oxidation. For such products, a higher nitrogen content in the MAP can help prevent rancidity.
Container Filling: Ideally, the product should occupy 60-75% of the container volume. This balance ensures adequate gas-to-product interaction while minimizing the headspace for microbial activity.
Influence of Humidity and Pressure: High humidity in the packaging can accelerate spoilage and microbial growth. The packaging process should aim to minimize humidity. Pressure changes during transportation can affect gas mixtures, but modern MAP technologies are designed to withstand these changes.

Sausages

Typical Ratio for Sausages: A common MAP gas mixture for sausages is 70% Nitrogen (N₂) and 30% Carbon Dioxide (CO₂). This combination helps in preventing oxidation (aided by nitrogen) and inhibiting microbial growth (aided by carbon dioxide).
Considerations for Specific Types of Sausages:
- For fresh, uncooked sausages, a slightly higher oxygen content might be used to maintain colour, similar to fresh meats.
- For smoked or cured sausages, a higher nitrogen content is often preferable to minimize oxidation, especially if the sausages contain higher fat content or spices prone to rancidity.
Factors Influencing MAP Ratios for Sausages:
- Fat Content: Higher-fat sausages may require more nitrogen to prevent rancidity.
- Colour Preservation: If maintaining a fresh colour is important, a balance with a small amount of oxygen might be considered.
- Spices and Additives: Certain spices and curing agents can influence oxidative stability.
Consumer Preference and Shelf Life: The MAP ratio should be adjusted based on the desired shelf life and consumer preference for taste and appearance.

Consumer-Friendly Tips

Always check the “use by” date on MAP-packaged meats.
Store MAP-packaged meats in the refrigerator, even if unopened.
Discard any MAP-packaged meat that has an off-smell, slime, or discolouration.

Conclusion

MAP is a versatile tool for extending the shelf life and maintaining the quality of a wide range of meat products. By selecting the appropriate gas mixture for each type of meat, retailers and consumers can enjoy fresher, safer, and more appealing meat products for longer periods. Remember, while MAP significantly extends shelf life, it doesn’t replace good hygiene and refrigeration practices.

For meat scientists and industry professionals, continuing research and advancements in MAP technology promise even greater efficiency and effectiveness in meat preservation, making it a continually evolving and fascinating field of study.