What is Freeze-Dried Food?October 21, 2014 by Melanie Swick | Be the first to comment »
Canned foods are commonplace in pantries because they are inexpensive, convenient, and durability. Developed as a way to preserve food for future consumption at home and commercially, the process of canning changed the distribution and marketing of many products. Almost all canned goods have a shelf-life of one or two years so long as the can remains undamaged. Foods with high acid such as tomato products have a shorter shelf-life. (It’s important to point out that “shelf-life” refers only to ideal flavor and texture—canned goods will last indefinitely.) In addition, safety issues have increased over the past few years because improperly packaged or stored canned products may contain contaminants such as Bisphenol A (BPA), which is used in liners. Clostridium botulinum that causes food poisoning has also been found in canned foods.
Ready-to-Eat (MRE) foods, introduced by the US military to provide field rations to its service members when food preparation facilities are unavailable, are lightweight and withstand extreme conditions. MREs are easy to store and transport but have a shelf life of two to three years. Research at the Pennington Biomedical Research Center in Baton Rouge observed that even though MREs provide meals on the move, troops were missing out on essential nutrients.
The process of freeze-dried started during the Second World War. Soldiers wounded in active combat required medicines, blood, and blood plasma. At that time the normal storage and transport procedures were insufficient for long term preservation and damaged the quality of the organic components. The freeze-dried method, developed to preserve the biochemistry and pharmacology of blood, allowed for storage of large amounts without refrigeration. Freeze-dried transformed the pharmaceutical approach of storing microorganisms, since over lengthy periods of time, medicines and life-saving blood products can easily be revived.
Recently, the process of freeze drying is becoming popular as a method of preserving food. Nestle introduced the first freeze-dried food product, coffee, in the 1960s. Sublimation, also known as lyophilisation, lyophilization, or cryodesiccation, removes any moisture by first freezing a substance and then placing it in a vacuum, which removes the oxygen, and almost all the water turns from ice into vapor. The product is then immediately stored in an air tight container or packages that cannot be penetrated or damaged. The process maintains many of nutrients and raw components so that freeze-dried foods are similar in their appearance and taste to the naturally occurring item. There is little or no spoilage, and the products can be stored for more than twenty years and almost anywhere. The packages weigh much less than the original item, which also allows for easy transportation.
NASA may have popularized freeze-dried food during space missions for their astronauts, but recently hikers, campers, and sports enthusiasts are benefiting from the products. Almost any food can be freeze-dried including fruits, vegetables, meats, fish, dairy products, eggs, pastas, and even entire meals. Furthermore, since little preparation is required, they are useful for emergency preparations both for families and during critical situations such as temporary facilities during large scale evacuations.