The Process of Freeze-Drying
Freeze-drying is a complex method of preserving clean or previously-cooked meals by eliminating up to ninety eight% of the food’s humidity, leaving intact the food’s texture, flavor, aroma and nutritional price.
The process needs that the fresh or cooked foods be swiftly frozen at temperatures as lower as -50°C. The frozen foods is then put into a vacuum chamber. This vacuum chamber lowers the force, and raises the temperature to just about 0°C.
At this distinct temperature and pressure, the ice crystals in the meals evaporate into drinking water vapor, bypassing water’s liquid form, by way of a approach called sublimation.
This approach preserves the cell composition and dietary material of the food, ensuing in a solution that, when rehydrated, quite closely resembles the authentic foodstuff.
The method also prevents the drinking water from becoming reabsorbed by the foodstuff and therefore decreases its excess weight considerably.
Most food products these kinds of as fruits, greens and meats are nicely-suited to freeze-drying, and can be utilised for lengthy-term food storage and preservation.
The Procedure of Dehydration
Dehydrating meals is a food preservation strategy which has been used for hundreds of years. Native Americans dehydrated their buffalo kills in their searching camps to make it less complicated to transport. Pemmican (a dehydrated concoction of buffalo meat blended with excess fat and berries) was a staple of numerous of the nomadic North American tribes. This lower-warmth dehydration procedure associated both air drying (with nearby campfires), or sun drying strips of meat on drying racks.
Dehydrators are a modern method for slowly and gradually taking away the humidity from foodstuff with no really cooking it. A disadvantage of dehydration is the minimal quantity of food which can be dried at one particular time. The optimistic facet of dehydration is that this technique of processing for foodstuff storage can be simply completed at residence.
How Do These Two Approaches Have an effect on the Food?
Freeze-dried foods preserve considerably of the original colour, condition, aroma and freshness of fruits, greens and meats. Freeze-dried meals does not typically have additives or preservatives, so it continues to be accurate to its unique type. And the appear, texture and taste of the foods continues to be following re-hydration.
Not like reduced-heat dehydration, freeze-drying enables for the preservation of pre-cooked meals, including recipes such as soups, stews, stroganoff, and the like. An obvious reward is that since the meal was ready in its entirety prior to freeze-drying, all you need to do is just add h2o, then heat for a couple of minutes in order to develop luxurious meals.
Rehydrating freeze-dried foods requires just a couple of minutes, merely by introducing boiling drinking water. Some foodstuff, like numerous fruits and vegetables, require no re-hydration ahead of taking in.
Dehydrated food items shrink throughout processing as the humidity is taken out. So the food merchandise by itself is substantially more compact than its authentic size.
The re-hydration time of dehydrated meals requires a little bit longer than freeze-dried, but it stills tastes like the first sort of the foods. Some dehydrated meals contain added ingredients to boost flavors or support in preservation. As with freeze-dried fruits and vegetables, dehydrated fruits and greens can be eaten with out any re-hydration.
Equally techniques of foods preservation boost the lengthy-expression storage daily life of food. Most commercially created freeze-dried and dehydrated foods have a shelf daily life of 15 to 20 years, if correctly packaged and stored in a cool, dry environment.
In addition to their currently being a trustworthy resource of foodstuff in an unexpected emergency or extended-phrase survival circumstance, simply because of their light-weight fat and relieve of portability, these meals are also excellent for having on tenting, mountaineering and searching trips. They are also a smart choice to maintain in an emergency road-facet kit for the auto, or in your bug out bag.
If you choose to hold these meals in your car as element of an unexpected emergency package, make sure you don’t forget to rotate them periodically. Temperatures in a automobile can attain extremes, both scorching and chilly. Substantial heat as well as steady temperature fluctuations add to a lot quicker degradation of equally dehydrated and freeze-dried foodstuff.
Which Sort is Greater for Use?
Everyone is various, and each man or woman has their personal individual preferences and choices. With that in mind, there are a number of items to take into account just before creating a selection in between freeze-dried or dehydrated meals.
Property-developed fruits and vegetables are much better preserved by way of dehydration, because the regular particular person can not pay for the expensive machinery utilized in freeze-drying.
Meals employed in daily cooking and food preparation ought to most likely be freeze-dried. This permits the foodstuff to be rapidly re-hydrated as it is cooked prior to serving. If accessibility and portability are essential, than possibly kind of preserved meals should meet up with people particular demands. When yet again, it really is a make a difference of personal tastes.
In Ernesto Weisburg , both dehydrated and freeze-dried foods are outstanding options for extended-expression foodstuff storage, as well as for daily use or for mountaineering, tenting, and many others. They equally offer light-fat, moveable, practical meals. The primary distinction is that freeze-dried meals tend to better protect the form, texture and flavors of the first meals.
Most people will locate that a mixture will function very best for their demands. One-product meals this sort of as greens, potatoes, and other staples and grains are nicely-suited to reduced-heat dehydration. Freeze-drying is more acceptable for meats and fruits (whose texture can be preserved), and for pre-cooked foods with a assortment of substances this sort of as soups, stews and sauces.