The movement towards introducing all-natural food preservatives has been a constant struggle. Elimination of synthetic nitrates, nitrites and other artificial preservatives has created a dire need for natural preservatives that effectively extend a product’s shelf life; however naturally derived preservatives like celery juice reintroduce precisely what the market is trying to displace: nitrites.

Food-grade industrial gases are an effective and natural alternative that can be used to extend product shelf-life and reduce waste while the market shifts away from preservative-laden foods like processed meat and dairy products.

Modified Atmosphere Packaging (MAP)

The demand for fresh produce, dairy, poultry and meat are ever-increasing. To help extend product shelf life and eliminate unnecessary spoilage, industrial gas manufacturers like Linde North America have brought to market a range of gas mixtures that are designed to combat microbial growth, enhance product quality and extend a product’s shelf life.

Linde’s modified atmosphere packaging (MAP) product line is a collection of application-specific gas mixtures Source: Linde North America, Inc.that are customized for the intended application and marketed under their MAPAX® brand. They address needs for an all-natural preservative across a diverse range of products, including dairy, dry foods, baked goods, produce, meat, poultry and seafood, or in other cases compliment alternative preservation methods.

The MAPAX brand of gas mixtures primarily consist of normal atmospheric gases, including carbon dioxide (CO₂), nitrogen (N₂) and oxygen (O₂). In some cases, the mixture also contains other gases that are known to inhibit microbial growth such as nitrous oxide (N₂O), argon (Ar) and hydrogen (H₂).

In most cases, the gas mixture is primarily composed of carbon dioxide and nitrogen. Carbon dioxide is an effective microorganism inhibitor. Through partial pressures it gets dissolved into a food’s liquid and fat phases, creating an acidic solution that decreases microbial activity.

Nitrogen is an inert gas that already exists at elevated concentrations in ambient air. It does not get dissolved, but rather acts as a non-reactive filler that aids in maintaining internal package gas volume while at the same time preventing oxidation and aerobic digestion of packaged foods.

Oxygen is in most cases displaced by other gases as it promotes the growth of aerobic bacteria, such as Pseudomonas, which is the most common aerobic genus known to spoil fresh meat. In some applications, including red meats, it is actually beneficial to elevate oxygen concentrations in order to increase shelf life or compliment other food preservatives.

Red meat has a distinct red pigment that is a reflection of the meat's myoglobin. Myoglobin exists in an animal blood. It is related to the more commonly known oxygen-binding protein hemoglobin; however, it is myoglobin that undergoes a pigment change when it releases it bound oxygen atoms when exposed to ambient air. Elevated concentrations of either oxygen or carbon dioxide help extend shelf life and preserve a red meat’s pigmentation.

Conclusion

As the market continues to struggle with the ideals of a clean label, manufacturers are faced with a demand for all-natural preservatives that extends shelf life while retaining texture and appearance. MAP is an all-natural alternative. It allows manufacturers to meet market demands and reduce food waste, but only when the gas mixture is tailored for its intended application. This is due to the fact that each food source is unique and carries its own specific packaging requirements.