An oxygen absorber is a type of packet or sachet that contains iron powder and other substances. Its primary purpose is to remove or reduce the level of oxygen within a sealed environment, such as a food package. Oxygen absorbers help prevent the oxidation of food and other perishable items, thereby extending their shelf life.
Here are the key features and functions of oxygen absorbers:
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Composition: Oxygen absorbers typically consist of iron powder, salt, activated charcoal, and a moisture-absorbing material such as clay. The iron reacts with oxygen to form iron oxide (rust) while the other components help facilitate the process.
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Hygroscopic Properties: Oxygen absorbers often contain hygroscopic materials that absorb moisture from the surrounding environment. This helps create a dry environment inside the package.
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Purpose: The main purpose of oxygen absorbers is to protect packaged goods, particularly food items, from the deteriorative effects of oxygen. Oxygen can lead to oxidation, rancidity, color changes, and the growth of spoilage microorganisms.
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Packaging Applications: Oxygen absorbers are commonly used in the packaging of a variety of products, including dehydrated foods, dried fruits, nuts, grains, cereals, coffee, and certain pharmaceuticals. They help maintain product quality by reducing or eliminating oxygen in the package.
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Types of Oxygen Absorbers:
- Iron-Based: The most common type, where iron powder reacts with oxygen to form iron oxide.
- Ascorbic Acid-Based: Some oxygen absorbers use ascorbic acid (vitamin C) to absorb oxygen. Ascorbic acid undergoes oxidation, reducing the oxygen level in the package.
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How They Work: Oxygen absorbers work through a chemical reaction in which the iron powder reacts with oxygen, forming iron oxide. This reaction occurs within the packet, and the oxygen is effectively removed from the enclosed space.
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Indicators: Some oxygen absorbers include color indicators that change over time. For example, they may start as pink and turn blue as the iron powder oxidizes. This color change can provide a visual indication of the absorber's effectiveness.
It's important to note that oxygen absorbers are meant for use in sealed environments, and they are not suitable for use in non-airtight packaging. Additionally, they should be used according to the manufacturer's instructions, and any unused absorbers should be stored in a sealed container to prevent them from prematurely activating.
