All About Oxygen Absorbers and How to Use Them

All About Oxygen Absorbers and How to Use Them
Published On:March 22, 2022 Revised On:August 1, 2024

The concept and application of oxygen absorbers originated in the early 20th century, evolving in the 1960s as the need for innovative food preservation techniques grew, especially within the military and emergency food sectors. Over time, oxygen absorbers’ adoption expanded into the consumer market, driven by advancements in materials science that enhanced their efficiency and application spectrum.

Definition and Overview

Oxygen absorbers, scientifically termed oxygen scavengers, are chemical entities designed to eliminate oxygen from a sealed environment. Their primary utility is in extending the shelf life and maintaining the quality of perishable goods by preventing oxidation.

Typically consisting of a blend of iron powder and a catalyzing salt, these absorbers reduce ambient oxygen levels in packaging to less than 0.01%, thus inhibiting oxidative reactions that can lead to spoilage and degradation.

The operational mechanism of oxygen absorbers is rooted in the chemical principles of oxidation-reduction reactions. The core of the absorber packet contains iron powder that, upon exposure to oxygen, undergoes oxidation to form iron oxide.

This process is accelerated by moisture and a catalytic salt, which drive the conversion of elemental iron into its oxidized form, effectively scavenging oxygen from the environment. This reaction is exothermic, and its efficiency is influenced by various factors, including the ambient moisture, the concentration of oxygen, and the volume of the container being preserved.

Types of Oxygen Absorbers

Each type of oxygen absorber offers unique benefits, and their applicability is primarily dictated by the product’s specific requirements, including sensitivity to contaminants, moisture levels, and the desired shelf life. The choice among these types involves a trade-off between efficiency, cost, and the potential impact on the product.

Iron-Based Absorbers

Iron-based oxygen absorbers are the most prevalent type, employing finely powdered iron as the primary reactive agent. Upon exposure to air, the iron undergoes oxidation, a process catalyzed by salt and moisture, effectively scavenging oxygen from the surrounding environment.

This category of absorbers is distinguished by its robustness and efficiency in a wide range of conditions, making it particularly suitable for the food industry. Iron-based absorbers are commonly used in packaging dry food products such as nuts, snacks, grains, and powdered foods, where preventing oxidation is crucial to maintaining freshness, nutritional value, and shelf life.

Organic Compound Absorbers

Organic compound absorbers utilize organic materials or compounds that react with oxygen to remove it from packaging environments. These absorbers may include ascorbates, photosensitive dyes, and unsaturated oils, which can undergo oxidation, reducing oxygen concentration.

Though less common than iron-based types, organic oxygen absorbers offer specific advantages, such as the potential for being food-safe and leaving no by-products that might affect the taste or quality of the product. They are particularly useful in sensitive applications, such as in packaging organic and natural food products, where the addition of non-organic substances is undesirable.

Others

Beyond the widely used iron-based and organic compound oxygen absorbers, there are specialized types designed for specific applications. These include:

  • Photosensitive Dye-based Absorbers: These are employed in products sensitive to light and oxygen, such as photographs and artworks.
  • Enzyme-based Absorbers: Utilize enzymes that catalyze reactions consuming oxygen. These are less common due to their higher cost and specific storage requirements but are used in high-value medical and pharmaceutical applications.
  • Metallic Oxides: Certain metallic oxides other than iron, like manganese oxide, can also act as oxygen scavengers under specific conditions. Cost, reaction conditions, and the specific needs of the preserved product limit their use.

Applications of Oxygen Absorbers

The versatility of oxygen absorbers across these diverse applications highlights their crucial role in protecting and preserving a wide range of products and items from the detrimental effects of oxygen exposure.

Food and Beverage Industry

Oxygen absorbers are extensively used in the food and beverage industry to enhance the shelf life and maintain the quality of packaged foods. By effectively reducing the oxygen levels within the packaging, these absorbers prevent the oxidation of fats, oils, and other sensitive components, preserving freshness, taste, and nutritional value. Common applications include:

  • Snack Foods: To prevent rancidity in nuts, chips, and other snack items.
  • Grains and Legumes: These are used to preserve the freshness and extend the shelf life of rice, beans, and other bulk staple foods.
  • Processed Meats: Jerky, dried meats, and other products in packaging where oxygen can accelerate spoilage.
  • Coffee and Tea: To maintain aroma and prevent staleness in whole bean and ground coffee and loose and bagged teas.
  • Prepared Meals: In the packaging of ready-to-eat meals, oxygen absorbers help maintain taste and prevent spoilage without preservatives.

Pharmaceuticals and Healthcare

In the pharmaceuticals and healthcare sector, oxygen absorbers preserve the efficacy and extend the shelf life of drugs and medical devices. Oxygen can degrade pharmaceutical compounds, reducing their effectiveness. Similarly, medical devices are susceptible to oxidation, compromising their safety and functionality. Applications include:

  • Pharmaceutical Packaging: To prevent the oxidation of vitamins, nutraceuticals, and other medications sensitive to oxygen.
  • Medical Devices: In packaging devices and components, oxygen absorbers help ensure sterility and integrity by preventing oxidative damage.
  • Diagnostic Kits: Protect diagnostic reagents and kits from oxidative degradation to maintain their reactivity and accuracy.

Collectibles and Preservation

The preservation of collectibles, art, documents, and photographs relies on maintaining an environment free from oxygen to prevent the oxidative deterioration of materials. Oxygen absorbers are used to create such controlled environments, thereby preserving the integrity and value of these items. Specific applications include:

  • Museum and Archive Storage: Oxygen absorbers help prevent oxidation, which can lead to fading, discoloration, and degradation, when valuable documents, manuscripts, and artworks are stored.
  • Collectible Items: Oxygen absorbers are used by collectors of rare books, coins, stamps, and other valuable items to maintain their condition and protect them from the harmful effects of oxygen exposure.
  • Photographic Storage: Oxygen absorbers are included in storage solutions to prevent the fading and yellowing of photographic prints over time, ensuring long-term preservation.

How to Use Oxygen Absorbers

Using oxygen absorbers involves understanding the specific needs of the preserved product, carefully integrating the absorbers into the packaging process, and diligently monitoring their effectiveness over time. By adhering to the proper guidelines, users can significantly enhance the shelf life and quality of a wide range of sensitive products.

Selecting the Right Type and Size

The efficacy of oxygen absorbers in preserving product quality is significantly influenced by selecting the appropriate type and size for the specific application. The selection process involves considering the product’s sensitivity to oxygen, the volume of the packaging, and the desired shelf life. Here are key considerations:

  • Product Sensitivity: Evaluate the product’s susceptibility to oxidation and choose an absorber that matches its preservation needs. For highly sensitive products, a more potent absorber may be necessary.
  • Packaging Volume: Determine the internal volume of the packaging and use this information to select an oxygen absorber with the correct capacity. Manufacturers typically provide guidelines on the absorber size required for different volumes.
  • Absorber Type: Based on the product’s requirements and any regulatory considerations, especially for food and pharmaceuticals, decide between iron-based, organic compound, or other specialized oxygen absorbers.

Packaging Considerations

Integrating oxygen absorbers into packaging requires careful planning to ensure their effectiveness. Follow these best practices:

  • Seal Integrity: After inserting the oxygen absorber, ensure the packaging is tightly sealed. Any leaks can render the absorber ineffective by allowing outside air to enter continually.
  • Placement: Position the oxygen absorber near the top of the package so it can efficiently absorb oxygen as it rises. Ensure it does not interfere with the product or packaging process.
  • Packaging Material: To maximize the lifespan and efficiency of the oxygen absorber, use packaging materials with low oxygen permeability. Ideal materials are Mylar bags, thick poly bags, or glass containers with airtight seals.

Monitoring and Replacement

To maintain optimal preservation conditions, monitoring the effectiveness of oxygen absorbers and replacing them as necessary is essential.

  • Indicator Tags: Some oxygen absorbers have indicator tags that change color when the absorber is exhausted. These tags can provide a visual cue to replace the absorber.
  • Physical Inspection: For absorbers without indicators, check for signs of physical change. An absorber that has become hard or swollen may indicate it has reached its absorption capacity.
  • Regular Checks: Schedule regular inspections of your packaged products, especially if they are stored for long periods. Replace absorbers if the packaging shows signs of air infiltration or if the product shows signs of oxidation.

Conclusion

Oxygen absorbers play a pivotal role in preserving various products’ quality, freshness, and integrity, ranging from food and pharmaceuticals to collectibles and medical devices. They offer a means to significantly extend the shelf life of perishable items without the need for harmful preservatives or costly packaging solutions. It is critical to select the right type and size of oxygen absorber, integrate it properly into packaging, and adhere to best practices for monitoring and replacement.

Stream Peak International provides high-quality oxygen absorbers, leveraging Japan-grade materials and technology for unmatched effectiveness and reliability. As we advance our products, we underscore the importance of using oxygen absorbers to enhance preservation and sustainability by minimizing waste. This guide aims to share the knowledge to utilize oxygen absorbers effectively, ensuring preservation needs are met with the highest standards.

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