In last article we cover some information about advantages of freeze-dried food. Of course dehydrated food is not perfect and you need to know some of the main problems related to this topic. So, without unnecessarily prolonging lets see major disadvantages of dehydrated food.
Only selected food can be freeze-dried
This type of process is not suited for all types of food. Usually people dehydrate fruits and meats. But I personally saw freeze-dried spaghetti and stew. Of course due to character of the process the meal have to contain water to be dehydrated, and at the same time some foods need to be specially prepared (usually with a lot of time) for the dehydration process.
Process is expensive
As you know form our previous articles, dehydration process needs vacuum for its proper operation. And device that can produce vacuum are usually very expensive and need a lot of energy. That’s why this process is not very efficient, especially in home use.
Storage problems
You also need to know about some problem with food storage. First of all dehydrated food should be storage in hermetically sealed or airtight, moisture-tight containers. The second problem is if freeze-dried foods are not stored correctly, or if they are subject to humidity, they will deteriorate very fast.
As you can see this kind of food processing got some own problems and disadvantages. These are only main problems. I didn’t mention about some minor disadvantages, such as need of boiling water for the proper preparation of a meal, or some loss of taste. Of course we don’t eat dehydrated food all the time - it has it own purpose.
Monday, September 24, 2012
Tuesday, September 18, 2012
Benefits of freeze-dried food
In last articles we learn about Dehydrated food. We also know how Freeze-drying process looks like in reality, and where we use it. Now it’s time to discover some great benefits of using freeze-dried food.
Long period of validity
Possibility for long storage of food was one of the main reasons why military and scientists start to thing about freeze-drying in the first place. When dehydrated product is stored in good vacuum sealed containers it can last for years. That’s why almost all emergency food storages are filed with freeze-dried food.
Nutritional value and taste
If you ever been in a long difficult journey, you probably know how important are the morale and well-being. And there is nothing better for it than good, tasty and complete nutritional food. And that is what freeze-dried food provides, and that is why so many climbers and travelers highly appreciates this type of food.
Size & weight
Size does matter. Of course, in terms of occupied space. This is another advantage of the freeze-dried food. Not only drastically reduces the size of our food, but also significantly decreases its weight, which is important for applications in travel. This advantage is most important when it comes to space travel. As all of you probably know, every pound that needs to be lifted to spaces costs hundreds of thousands dollars.
Easy to prepare
To prepare freeze-dried food all you need is boiling water and few minutes of your time. And that’s it - you are ready to enjoy your quick and nutritious meal.
Long period of validity
Possibility for long storage of food was one of the main reasons why military and scientists start to thing about freeze-drying in the first place. When dehydrated product is stored in good vacuum sealed containers it can last for years. That’s why almost all emergency food storages are filed with freeze-dried food.
Nutritional value and taste
Size & weight
Size does matter. Of course, in terms of occupied space. This is another advantage of the freeze-dried food. Not only drastically reduces the size of our food, but also significantly decreases its weight, which is important for applications in travel. This advantage is most important when it comes to space travel. As all of you probably know, every pound that needs to be lifted to spaces costs hundreds of thousands dollars.
Easy to prepare
To prepare freeze-dried food all you need is boiling water and few minutes of your time. And that’s it - you are ready to enjoy your quick and nutritious meal.
Thursday, January 19, 2012
Where we use freeze-drying?
As I mentioned in previous articles freeze-drying is one of few food dehydration methods. In this article I would like to write something about other usage of this extremely useful technology. Freeze-drying is quite new technology, but people already find some interesting usage possibilities. Lets look at some of them.
Food freeze-drying
As mentioned in last articles freeze-drying food was one of the first and basic usage of this type of dehydration. The process has been popularized in the forms of freeze-dried ice cream by NASA, an example of astronaut food. Dehydrated food is very lightweight, and it can last a lot longer than standard frozen meals. It is also widely used to produce essences to add to food, and Freeze-dried fruits are used in some breakfast cereal or used as a snack.
Pharmaceutical usage
Pharmaceutical companies often use freeze-drying technology to enlarge the shelf life of their products - vaccines for example. By dehydration material and sealing it in a vial, they can be easily shipped, and later reconstituted to its original shape for proper use. Another example from the pharmaceutical industry is the use of freeze drying to produce tablets. Dehydrated pills are rapidly absorbed, and easily administered.
Technology
A lot of chemistry compounds are often freeze-dried, so they can be more stable and easier to dissolve in water. For mass usage freeze-drying is very expensive process, which got really high energy demands. We must consider that dehydration is a long time process and not always best for storing and transporting things. It’s often use for materials that are heat-sensitive, such as proteins, enzymes, microorganisms, and blood plasma.
Some other uses
Food freeze-drying
As mentioned in last articles freeze-drying food was one of the first and basic usage of this type of dehydration. The process has been popularized in the forms of freeze-dried ice cream by NASA, an example of astronaut food. Dehydrated food is very lightweight, and it can last a lot longer than standard frozen meals. It is also widely used to produce essences to add to food, and Freeze-dried fruits are used in some breakfast cereal or used as a snack. Pharmaceutical usage
Pharmaceutical companies often use freeze-drying technology to enlarge the shelf life of their products - vaccines for example. By dehydration material and sealing it in a vial, they can be easily shipped, and later reconstituted to its original shape for proper use. Another example from the pharmaceutical industry is the use of freeze drying to produce tablets. Dehydrated pills are rapidly absorbed, and easily administered.
Technology
A lot of chemistry compounds are often freeze-dried, so they can be more stable and easier to dissolve in water. For mass usage freeze-drying is very expensive process, which got really high energy demands. We must consider that dehydration is a long time process and not always best for storing and transporting things. It’s often use for materials that are heat-sensitive, such as proteins, enzymes, microorganisms, and blood plasma.
Some other uses
- Books and documents water damaged from flooding.
- Stabilization or storage of biological materials for research and development
- Preserved petals and whole flowers for decoration. Preserving wedding bouquets and memorial flowers.
- Animal preservation for deceased pets and hunting trophies.
Tuesday, January 10, 2012
How freeze-drying process looks like?
As you may already know freeze-drying is a type of food dehydration with some excellent results and advantages. You can store a freeze-dried meal for years, and then, when you're finally want to eat it, you can completely revitalize it with a cup of hot water. Even after all those years the taste, texture and nutritional values will be pretty much the same. Lets look like typical process of food dehydration looks like.
Food preparation
In the beginning we must prepare our meal before we start freeze-drying it. The most freeze-driers used in home environment are quite small, so we can’t actually put in it the whole fruit or meat. First we must slice it to equal pieces. It will help with drying process and packaging afterwards. Nice sliced pieces goes directly to our freeze-drier, and our job is done. But what happens inside of the device?
Freeze-drying
First our food must be frozen solid, which separates the water from everything around it, on a molecular level, even though the water is still present. Next, the machine turns on the vacuum pump that will provide a very low absolute pressure, even below .06 ATM. It is worth to mention its lower than the pressure of outer space! Last step is to provide small amount of heat to the shelves, causing the ice to change phase. Since the pressure is so low, the ice turns directly into water vapor. This process continues for many hours, sometimes even days, while the material gradually dries out.
Vacuum packing
The last thing we need to do, is select the method of packing. In my opinion the best result you will get with vacuum packing. It's a method of packaging that removes air from the package before sealing. It can involve both rigid and flexible types of packaging. As long as the package is secure, the material can sit on a shelf for years and years without degrading, until it's restored to original form with a bit of water. It is worth to mention that even using freeze-drying method for storing your food, it will eventually spoil, due to very small amount of moisture remaining in food.
Food preparation
In the beginning we must prepare our meal before we start freeze-drying it. The most freeze-driers used in home environment are quite small, so we can’t actually put in it the whole fruit or meat. First we must slice it to equal pieces. It will help with drying process and packaging afterwards. Nice sliced pieces goes directly to our freeze-drier, and our job is done. But what happens inside of the device?
Freeze-drying
First our food must be frozen solid, which separates the water from everything around it, on a molecular level, even though the water is still present. Next, the machine turns on the vacuum pump that will provide a very low absolute pressure, even below .06 ATM. It is worth to mention its lower than the pressure of outer space! Last step is to provide small amount of heat to the shelves, causing the ice to change phase. Since the pressure is so low, the ice turns directly into water vapor. This process continues for many hours, sometimes even days, while the material gradually dries out.
Vacuum packing
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| Freeze-dried bacon bars |
Monday, January 9, 2012
Dehydrated food – what is it?
I’m sure from time to time you hear something about dehydrated food or freeze dried food. Do you ever wonder what is it? Why a lot of people using it? And how it actually works? In this article and blog I would like to cover this topics as accurately as I can. Hope you will enjoy my articles and learn from them some new, fun information’s. OK. So lets start and talk about Freeze-drying and how it affects our food.
How Freeze-drying work?
In simple words we want to get rid all of the water from our products. We can do it by freezing the object and then reducing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase. Of course we are unable to make this process without special equipment. From some time on market we can find home food freeze dryers, which made dehydrating food much easier and cheaper.
Why we dehydrating food?
The main reason why we dehydrate food is to preserve it for longer time. Dehydration also decreasing size and weight of our meal, which make it easier to transport. In dehydrated form its less sensitive to temperature. But what makes freeze drying even more special, its what it will taste almost exactly the same as first prepared meal, and what is also important it will have the same nutritional value.
You may ask what kind of food do we freeze drying? First the process has been popularized by NASA, so all kind of food that astronauts get with them to space is dehydrated. Most famous are freeze-dried ice creams, which you can buy at NASA visitor center gift shops. It is also usually used to produce essences or flavourings to add to food. Other popular items often dehydrated are: fruits, coffee, meat and pet food.
How Freeze-drying work?
In simple words we want to get rid all of the water from our products. We can do it by freezing the object and then reducing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase. Of course we are unable to make this process without special equipment. From some time on market we can find home food freeze dryers, which made dehydrating food much easier and cheaper.
Why we dehydrating food?
The main reason why we dehydrate food is to preserve it for longer time. Dehydration also decreasing size and weight of our meal, which make it easier to transport. In dehydrated form its less sensitive to temperature. But what makes freeze drying even more special, its what it will taste almost exactly the same as first prepared meal, and what is also important it will have the same nutritional value.
You may ask what kind of food do we freeze drying? First the process has been popularized by NASA, so all kind of food that astronauts get with them to space is dehydrated. Most famous are freeze-dried ice creams, which you can buy at NASA visitor center gift shops. It is also usually used to produce essences or flavourings to add to food. Other popular items often dehydrated are: fruits, coffee, meat and pet food.
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