What is freeze drying?

Currently, a technique developed by two French people in 1906 is used. Did you know that this is the method that gives the best results among all the conservation solutions ? For what ? Because the taste, the appearance of the food, the nutritional values ​​are preserved, all with a saving space , weight and shelf life very long! Focus on this freeze-drying technique .

Freeze drying: where does it come from and how does it work?

It was during the Second World War that the principle of freeze drying has been improved in order to be able to transport vaccines without being hampered by problems of refrigeration and maintaining the cold chain is often too uncertain.

Then it's the turn of NASA to take an interest in the food part, allowing us to feed our astronauts on mission in a varied manner and with good nutritional quality.

Finally, freeze-drying will become known to the general public through its flagship product: freeze-dried coffee !

There freeze drying is therefore a vacuum drying process at low temperature of products previously frozen at -40°C according to a freezing process as quickly as possible.

This means that it is a gradual elimination of water of the product which is previously frozen (solid phase) by passing to the vapor phase , without going through the liquid phase. This change of state is called sublimation . If we detail this process of sublimation: the frozen water evaporates quickly thanks to an environment that becomes void of air when the temperature of the food rises to 0°C because the solid water cannot become liquid again in this environment deprived of air and therefore it passes into the gaseous state and evaporates.

This gives a product with less than 5% water residual up to less than 1% for the freeze dryers very efficient. It is ultimately a dry product but which retains all the organoleptic characteristics of the starting product (and therefore the pieces of food) because the dehydration is done after freezing and under vacuum.

However, it is necessary that at the end of the freeze-drying process , the sealing of freeze-dried foods is done in a container allowing them to be protected from humidity and oxygen to have a long shelf life , which explains the sometimes somewhat “massive” and imposing appearance of the containers.

Interest and advantages of freeze-drying

THE freeze-dried foods are therefore very interesting when the sporty seeks weight gain and significant energy density, as is the case with ultra races, extreme hikes for example where the athlete must be self-sufficient and manage its daily rations . For these products, the storage life at normal temperature can be up to several years. THE freeze-dried foods keep their vitamins , their organoleptic qualities (texture, color, flavor, etc.) and physical . Of course the weight and volume of food are greatly reduced, hence the practicality of use in sports. complete autonomy .

Also from a taste and appearance point of view: freeze-dried products have the same initial taste and appearance as fresh products, this does not harden the food and the shapes, aromas and flavors are preserved.

Athletes, hikers, itinerants and fans of bivouacs or stage races: why will the solution of freeze-dried meals appeal to you?

Without a doubt, for all the following reasons:

- Taste, appearance, nutritional values : it is, in the mouth, the same sensation as a fresh product, the pieces are preserved and the taste too, especially when a chef participates in the development of recipes as is the case in the products of the expedition range from MX3 Nutrition! Freeze-drying allows more than 95% of the nutritional values ​​of freeze-dried products to be preserved, whereas dehydration, which uses a heat technique, only allows 60% of the product's vitamins and minerals to be preserved!

- The duration of the conversation : this can reach several years or even up to 15 or 25 years depending on the container used. For comparison, just dehydrated food and products frozen at home only last for 2 years on average.

- Weight and size : this is the major argument for all sports and traveling lovers, because once the water is removed from food, the products are very light because for example for fruits and vegetables, as their percentage of water is very high at the start, once freeze-dried, they weigh almost nothing! But above all, freeze-drying offers considerable space savings, allowing you to organize your bag and transport large quantities of freeze-dried meal rations.

For preparation , nothing could be simpler because you just need to rehydrate the dishes in hot or cold water depending on the recipes. Then wait a few minutes to be able to taste them.

The good news This is because manufacturers are now able to offer a very wide range of freeze-dried products. From breakfast At dessert, everything is freeze-dryable !

Also from aligot to fish with white butter, muesli or scrambled eggs, it is possible to eat healthy and varied at sea, on mountain trails or even sitting on the sand of the dunes of a desert.

What are the limits of freeze-drying?

Be careful, these solid foods have a porous appearance, are very friable and they are hungry for water like dehydrated products and therefore, must be kept sheltered humidity.

There freeze drying technique is often very expensive, which generates fairly high product cost prices and lastly, it is not possible to freeze-dry only foods that are small in size, powdered or cut into small pieces, so don't expect to find a whole chicken thigh or even a fish fillet in your freeze-dried dish.