How to Use Ethylene Absorbers?

Gas absorption involves the removal of specific gases from the environment, a process achieved through physical or chemical means.

In the context of ethylene and oxygen absorbers, the mechanism typically involves chemical reactions where the target gas is irreversibly bound to the absorber material. Ethylene absorbers often use potassium permanganate or activated carbon, which oxidizes ethylene to carbon dioxide and water, effectively removing it from the air.

Oxygen absorbers commonly utilize iron powder, which reacts with oxygen to form iron oxide, reducing the oxygen levels in the environment. These reactions are facilitated by catalysts and occur under specific humidity and temperature conditions, optimized to maximize the efficiency of the absorption process and ensure the stability of the products being protected.

Ethylene in the Aging and Ripening Process

Ethylene is a naturally occurring plant hormone significantly influencing fruits and vegetables’ ageing and ripening processes. It acts as a signaling molecule, triggering various biochemical pathways that lead to texture, color, and flavor changes.

Ethylene’s impact is dose-dependent; low concentrations can initiate the ripening process, while higher levels accelerate it, often leading to over-ripening or spoilage. This makes managing ethylene levels critical in post-harvest and storage phases to control the ripening process and extend the shelf life.

Oxygen on Product Degradation and Spoilage

Oxygen plays a dual role in product packaging; it is essential for respiration in some fresh products but also contributes to oxidative spoilage across various food and pharmaceutical products.

Oxygen can react with organic compounds, leading to rancidity in fats, color changes in fruits and vegetables, and the degradation of vitamins such as Vitamin C and Vitamin A. In pharmaceuticals, oxygen exposure can lead to the degradation of active pharmaceutical ingredients, reducing efficacy and altering drug profiles.

Understanding Ethylene Absorbers

Ethylene absorbers are packaging materials used to capture and neutralize ethylene gas, a plant hormone that triggers the ripening process in fruits and vegetables. These absorbers function through a chemical reaction, converting ethylene gas into less reactive compounds, typically carbon dioxide and water.

Advantages

Extends Shelf Life: These absorbers extend the shelf life of perishable products by controlling the concentration of ethylene.
Maintains Quality: Reduces the risk of premature ripening and spoilage, maintaining produce’s nutritional and aesthetic quality.
Versatile Applications: Suitable for a variety of settings, from industrial to retail and home use.

Limitations

Cost: Especially for potassium permanganate-based absorbers, the cost can be higher than other preservation methods.
Disposal Issues: Used absorbers, particularly those containing potassium permanganate, must be disposed of carefully due to their chemical content.
Environmental Conditions: Environmental factors can influence effectiveness; for example, high humidity can reduce the lifespan and capacity of some absorbers.

Types of Ethylene Absorbers

Potassium Permanganate-Based Absorbers: Potassium permanganate-based absorbers work by oxidizing ethylene gas when it comes into contact with the potassium permanganate impregnated in a carrier like alumina or silica gel. The reaction transforms ethylene into carbon dioxide and water, effectively removing it from the air. These absorbers are typically packed in porous sachets or containers that allow air circulation while preventing spillage of the active material.

Activated Carbon Absorbers: Activated carbon absorbers use the adsorption properties of activated carbon to trap ethylene molecules within the carbon’s porous structure. While less chemically reactive than potassium permanganate, activated carbon can be impregnated with other substances to enhance its ethylene adsorption efficiency. It is commonly used due to its broad effectiveness and ability to adsorb a wide range of organic compounds.

Understanding Oxygen Absorbers

Oxygen absorbers remove oxygen from a sealed environment, substantially slowing and preventing oxidation and other oxygen-related degradation processes. These absorbers work by chemically reacting with oxygen to form a non-reactive compound, typically reducing the oxygen levels to below 0.01%, which substantially slows down the rate of spoilage, oxidation, and microbial growth.

Types of Oxygen Absorbers

Iron Powder-Based Absorbers: The most common type of oxygen absorber contains finely powdered iron. When exposed to oxygen, the iron oxidizes, converting it into iron oxide. This reaction also requires moisture, often included within the absorber packet in the form of salt and water absorbed from the surrounding environment. Iron powder-based absorbers are safe, economical, and efficient, making them suitable for a wide range of applications.

Organic Compound-Based Absorbers: These absorbers use organic compounds that react with oxygen to remove it from packaging. Examples include ascorbic acid or unsaturated oils that can oxidize quickly. While less common than iron-based absorbers, they are sometimes preferred for specific applications where the presence of iron is undesirable.

Ethylene Absorbers vs. Oxygen Absorbers

Ethylene absorbers and oxygen absorbers function based on different chemical principles aimed at preserving stored products by removing specific gases. Here’s a comparative analysis:

This table provides a concise overview, highlighting key differences in working principles, effectiveness under different conditions, cost, and longevity between ethylene and oxygen absorbers.

Conclusion

The choice between ethylene and oxygen absorbers should be guided by the application’s specific needs, environmental conditions, and cost considerations. Each type of absorber offers distinct advantages.

When deciding which absorber to use, consider the nature of the product, the expected storage conditions, and the economic impact of potential spoilage or degradation. It is also crucial to evaluate the integration of these absorbers into existing packaging and storage solutions.

Feature	Ethylene Absorbers	Oxygen Absorbers
Working Principles	Oxidative reactions or physical adsorption are used to remove ethylene.	Chemical reactions bind oxygen, primarily through iron oxidation, to form iron oxide.
Effectiveness in Environmental Conditions	Sensitive to humidity and temperature. Performance can vary with environmental changes.	Effective across a broad range of temperatures; effectiveness depends on packaging integrity.
Cost Analysis and Accessibility	Generally more expensive due to specialized materials. It is less widely used outside of agriculture and floriculture.	More widely available and used across various industries, often cheaper due to higher production volumes.
Longevity and Efficiency	Effective in controlled environments, lifespan may be shorter under less ideal conditions.	Long-lasting as long as the packaging remains intact; highly efficient in preventing oxidation-related spoilage.

Stream Peak International, a global supplier of oxygen absorbers, uses high-quality materials and advanced technology from Japan. We are committed to delivering solutions that extend food products’ shelf life and freshness worldwide. We aim to reduce waste throughout the supply chain and contribute to sustainability efforts by improving food preservation.

Using Ethylene and Oxygen in Packaging