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By removing water from food and drug products, stability and degradation can be reduced. The lower the water content in a food, the longer a food can potentially last. It makes it more difficult for life to grow, by salting and dehydrating food, the food can last longer.
On a side note-
This is often misrepresented online and on children's websites. The Incas did work at high altitudes, with low humidity and lower pressure, but it was not a level that reached sublimation. Think of it as "drying while at freezing temperatures".
The Incas would freeze and then dry their food, in two separate steps, as opposed to "freeze-drying" or the modern pharmaceutical and food term lyophilization. The Incas placed their food in cold climates to freeze at night to store as you would a freezer, and then in the day it would evaporate. This process is closer to dehydration and then a freezing step, and wouldn't remove some of the internal water that modern processes would.
Freeze-drying requires a vacuum and low temperatures ie. drying while at cold temperatures. In order for this to occur, to have the water inside the food go from liquid to gas (sublimation) , a phase diagram shows that it needs to be less than .006 atm, far far below any environmental conditions the Incas could achieve. This value, .006 atm (4.56 mm Hg) is known as the triple point of water, below this pressure, sublimation can occur.
For Instance:
Machu Picchu- 7,970 ft above sea level- lets say they wold climb to 10,000 feet at most for this process.
At 10,000 feet it would about 60.7 kPa air pressure- (526 mmHg or .69 atm)
You can see it is about 100 times too high a pressure to induce sublimation.
You wouldn't call homemade beef jerky freeze dried, you'd call it dehydrated.
It is a smart process, but it is not reminiscent of the way food and drugs are made nowadays. I have worked in this industry and am just pointing out that the it is semantics. A scientist wouldn't refer to this process as "freeze-drying", maybe a comma in between "freeze , drying" would make it work.
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What is the difference between dried food and freeze-dried food?
i think dried food is fresh
What is the difference between dried foods and freeze dried foods?
Drying food is done for preservation of food. Dried food can be either sun dried, spray dried (only in case of powder) or freeze dried. Freeze dried food is best method for food drying as no heating of food is required in this method so nutrient loss occur in freeze drying. For example freeze dried acai powder is more beneficial than spray dried one. Freeze Dried food are costlier than food dried by any other ways as freeze drying process require use of some costly equipments.
Do they sell freeze dried food at NASA?
In fact, they do still sell it there. You can buy freeze dried food at "The Space Shop" in NASA.
Where can I find more information on freeze dried food?
You can find more information about freeze dried food by researching with books. The library most likely has many books about freeze dried foods and how to do the process.
How is Astronaut food made?
Freeze dried
What is one advantage that freeze-dried foods have over frozen food?
An advantage of freeze-dried foods is that they are lightweight.
What is one advantage that freeze-dried foods have one over frozen food?
An advantage of freeze-dried foods is that they are lightweight.
What is the best way to do food storage?
Freeze dried food is the best method for keeping food fresh and hygienic. If you buy in bulk and need to preserve your food, freeze dried food is the best method to do so. There is an assortment of freeze dried foods like freeze dried fruits and freeze dried vegetables that one can purchase. The method is extremely effective and is better than freezing in the regular way as it keeps food stored for a long time.&&Intake of nutritious food keeps you healthy, and proper food storage is helpful in retaining the nutritional value of your edibles. Hence, it is essential to take food storage into serious consideration.
What is the difference from dried food and freeze-dried food?
Dried food, as its name implies, is food that has been dehydrated, or had most of the moisture content removed through the blowing of warm dry air around the food or by placing the food on screens in the sun on a dry, hot day. Food dehydration can easily be done at home with minimal equipment. Freeze dried food is made through a much more involved factory process that involves pretreatment of the food, a freezing stage that takes the food to very, very low temperatures, and then a two-part drying process that removes virtually all of the water content from the food. Freeze drying is a process that can not be done at home, as it involves sophisticated and expensive equipment. Dried food weighs more than freeze dried food; that is, if two cups of fresh fruit are divided evenly and half is freeze dried and the other simply dried, the freeze dried portion will be much lighter as more water was removed than in the drying process.
What is the purpose of freeze dried food for the Apollo 11?
As all freezed dried food are already cooked , so it can be eaten.
How would astronots eat?
They eat freeze dried food.
Who made freeze dried food?
Clarence birdseye made it
