Oxygen Absorbers- An Introduction
Oxygen absorbers, also known as oxygen scavengers, are small sachets that are placed in packages to remove or reduce the amount of oxygen. The level of oxygen needs to be maintained in closed packets, especially food packets, to ensure that the products placed inside do not get spoil or lose their freshness. A wide range of oxygen absorbers is available in the market. The oxygen absorber is usually sold in the form of porous sachets, packets and can also be found in packaging films. Some types of oxygen absorbers are an integral part of polymer structure.
The composition of an oxygen absorber depends on many factors. These include what it is being used for, the water activity of the packaged goods among others.
Oxygen Absorbers for Preservation of Food Products
Oxygen Absorbers are very important in the food industry. Many types of food products are packed and transported to different places and so it becomes crucial that they remain fresh and unspoilt till they reach their final destination. Oxygen Absorbers remove oxygen from the closed space, leaving behind nitrogen, which helps increase the shelf life of the food product. Most oxygen absorbers reduce the oxygen levels to around 0.1% or even lesser.
If food products are in an oxygen-filled closed atmosphere for a long time, it can get spoilt in many different ways. These include growth of micro-organisms like mold, fungus and being affected by bugs. Food products can also turn rancid. Condensation and oxidizing of the vitamin portions of the food items may also occur. These are some of the different ways in which food products get spoilt when they come in contact with oxygen.
How Oxygen Absorbers Work
Oxygen Absorbers are usually available in a sealed bag and hence it becomes important that once they are opened, they should be immediately placed in the designated package. Otherwise, if it is left in the open, the oxygen absorber will start absorbing oxygen from the outside atmosphere itself.
Oxygen absorbers work through a process of chemical reaction. The oxygen absorber sachets contain iron powder, which when coming in contact with the oxygen turns into rust. Thus, all the iron powder gets oxidized and in this manner, the oxygen absorber becomes “saturated”. The absorbing action will stop at this point of time. Next, place the oxygen absorber sachet out in the open and it will again start reacting with the outside oxygen till all the iron powder turns into rust.
Oxygen Absorbers cannot be used to preserve all kinds of products. They are best suited for those food items, which are low in moisture and oil content. If the vapor content is not less than 10%, then contact with oxygen absorbers will lead to botulism poisoning. Thus oxygen absorbers are best for protecting dry fruits from insect damage as the fruits have very less moisture content.