Oxygen Absorbers: Their Function and Use
Oxygen absorbers are little packets of iron powder packaged in a material that keeps the iron in, but allows oxygen and moisture to enter and be absorbed. The iron absorbs the oxygen causing the iron to rust. As it rusts, or oxidizes, it absorbs any oxygen that may be present.
Why do I need Oxygen Absorbers?
Oxygen and moisture are two factors that destroy the value of dehydrated and freeze-dried foods. Theses elements have a detrimental effect on color, flavor, vitamin content, and fats of stored foods. Oxygen will enhance the growth of insects, bacteria, mold, and yeast in your food, accelerating spoilage. Oxygen absorber help to remove the oxygen in your container, leaving nitrogen. Dry foods are protected against spoilage and bacteria growth in a nitrogen environment. A “nitrogen flush” is often used to force the oxygen out of a product before it is sealed for storage. But even when a nitrogen flush has been done, it's still wise to include an oxygen absorber inside the container to help eliminate any remaining moisture. During the freeze-drying or dehydrating process, much of the moisture causing molding or spoilage is eliminated. An oxygen absorber will help to mitigate any moisture that remains once the food is packaged. Foods with a high moisture or oil content should not be stored in reduced oxygen packaging because it can cause botulism poisoning. Only store foods with in low moisture (10% or less) with oxygen absorbers. Oxygen absorbers actually remove oxygen more effectively than vacuum packaging because they only remove the oxygen rather than all the air.
What Type of Containers do I Need?
[Metallized cans] with seamed lids, [metallized bags], PETE plastic bottles with airtight, screw-on lids, and glass canning jars with metal lids and gaskets all do well with oxygen absorbers. Do not use plastic containers that are not identified as PETE or PET under the recycling triangle on the bottom of the container. Metallized cans and bags prevent light, another source of spoilage, from reaching your food with the added help of your oxygen absorbers. Oxygen absorber packets come in different sizes, two of the most common are 500cc and 2000cc. To decide which size is right for you, consider the size of the container you'll store your food in and the amount of empty space between the food particles and between the top of the food and the lid of the container. Some companies that manufacture absorber packets rate them according to their oxygen absorption capacity in milliliters, while others do so by the equivalent air volume (the actual total amount of air between the product pieces).
How do I Preserve the Life of my Absorbers?
Store unused absorbers in small glass jars that have a lid and ring seal. A one-pint jar will hold 25 absorbers. You can also heat-seal them back into the bag they came in. Or you can store them in plastic freezer bags, but you must use them within the next few months because the plastic will slowly admit oxygen and shorten the lifespan of your absorbers. When using a combo like the Do-it-Yourself Superpail Kit, do not plan to package more food than you can in 20 minutes. Prolonged exposure to air in the room will speed up the demise of your absorbers. Instead, place the number of absorbers you expect to need for one batch of packaging on a tray . Use one absorber per package of food, and work as quickly as possible to preserve the life of the absorbers. When you are ready to do another batch, remove enough absorbers from their bag or jar for that batch. You'll know the lifespan of your oxygen absorber by its color. Some absorber packages turn pink when they're working properly and are still absorbing the oxygen in your can. Some turn purple or blue when they're used up.
COMMON DESICCANTS AND THEIR PROPERTIES
A desiccant is a substance that promotes drying by absorbing moisture or water vapor from the air. Consumers are probably most familiar with small paper packets of desiccants that are often packed with items so that they will not rust or mold during shipment, especially for imported items that will spend time in the hold of a ship between the time they leave the factory and arrive at the store.
In industrial settings, desiccants are used for the same reason in compressed air systems: to dry the air. The changes in pressure when air is compressed will cause water to condense, and this moisture must be removed. To do this, compressed air is passed over desiccant material to dry it out. There are several types of desiccants:
Silica occurs in nature as Silica dioxide, SiO2. It is processed into gel-like beads for use as a desiccant dryer. Silica gel was first used in World War I to absorb vapor in gas mask canisters. Pure silica gel is one of the few desiccants that is safe for use around food.
Indicating Silica Gel
Indicating silica gel is silica gel that is processed with cobalt chloride. The cobalt chloride will change color from blue to pink as the silica gel absorbs moisture. This ‘indicates’ when the silica gel is becoming saturated. Because cobalt chloride is a heavy metal salt, it cannot be safely used around food.
Clay that is high in magnesium aluminum silicate, a naturally occurring mineral, is processed into Montmorillonite clay for use in drying. It works best at room temperature or below. Clay is one of the most inexpensive desiccants, which makes it popular for industrial use
Quicklime and Gypsum
Quicklime is a common term for Calcium Oxide. It is alkaline and highly caustic, so special care in handling is necessary. Its chief benefit is that it can be used to gradually drop the humidity to a very low state. Gypsum is Calcium Sulfate.
Molecular Sieve is a synthetic desiccant manufactured from alumino silicates. Like the name sounds, it has many tiny holes or pores the absorb liquid and gas. It is a highly effective desiccant that can absorb water up to 22% of its own weight.
Most of these various types of desiccant dehumidifiers can be recharged and recycled by using a heating process to dry them for reuse.
Through extensive research, ethylene absorber has been able to provide innovative technologies that extend the freshness and quality of fresh food and flowers. Such thorough research has enabled us to launch our first commercialised product, a discreet but high-tech filter that removes the ripening hormone from around fresh produce.This is helping the global supply chain maximise value from growing, transporting and retailing top-quality produce for consumers, by extending quality, prolonging freshness and enhancing flavour in a secure and sustainable way.
It's Fresh! helps to address the key industry challenges of food security, profitability and global food waste.
It's Fresh! is a division of Food Freshness Technology Holdings a world class business that has invested over $20min areas such as the research and development of unique technologies and delivery systems, to bring to market a range of ground-breaking products that help leading retail groups and their supply chains to make a positive change to the fresh produce industry and to people around the world. These unique technologies are delivered via state-of-the-art materials science developed in partnership with world leading research & technology organisations.
To learn more about our research and what it means for the future of the 'fruit industry', check out our research page here
Our filter absorbs the ethylene gas given off normally as fruit ripens. By capturing this gas (before the fruit does) research has shown that your fruit will be kept in peak condition for longer, naturally. Proven across five continents to reduce waste and costs within the supply chain network It's Fresh! can deliver enhanced yields and returns;
For Growers and suppliers, by helping them to benefit from consistency and management of maturity, reducing grade-outs and rejections to deliver superior quality and extended product life.
For Retailers, by providing extended quality freshness and shelf-life, delivering reduced in-store waste, greater availability on-shelf and increased sales as satisfied consumers return to buy more fruit more often.
CO2 absorber has been used in anesthesiology for many years. However, this process is not limited to this field of medicine. Removing carbon dioxide from human environment is used in other areas as well: mining industry, submarines, scuba diving, space travel and many others. The rationale to remove carbon dioxide from confined spaces is that cannot be eliminated otherwise. Anesthesia practitioners are well aware of this component of the circle system, the carbon dioxide absorber. In daily practice the clinician is less concerned with what kind of substance fills the dedicated canister, as this is usually in the care of the maintenance personnel. The appearance of Sevoflurane and Desflurane, with their own chemical characteristics, prompted the clinician to dedicate new attention to these absorbents. The classical substances used for this purpose are different combinations of limes. The practical concern of the anesthesiologist is to notice when the absorbent is consumed and call for its replacement. Still, many other aspects remain: compound A formation with Sevoflurane, carbon monoxide formation with Desflurane and dry absorbent for instance. The latest member of these products in the medical field is the LiOH carbon dioxide absorbent. Although used for many years in the space exploration, its way into the operating room is a rather recent achievement. Special chemical properties and high absorptive capacity make this new type of absorbent an attractive option for modern anesthesia practice.