Freeze-drying is a particular drying process that aims to increase the shelf life of a product, while almost completely preserving its nutritional and organoleptic characteristics.
Foods intended for freeze-drying, often of biological and controlled origin, are initially chopped into small parts and eventually cooked and subjected to homogenization.
The actual freeze-drying process begins with the freezing of the minced foods, which are brought to a temperature between -30 and -50 ° C. This first step is necessary to block the degenerative processes of the food. Subsequently we proceed with the drying under high vacuum. The entire process, which exploits the physical and chemical properties of water, takes place in controlled environments and is called cryodrying. The packages are then hermetically sealed, in order to maintain the degree of dryness reached (less than one, maximum 2% humidity).
The complete dehydration of the food, in addition to not altering its original characteristics, allows to obtain (freeze-dried) products of much lower weight and volume (from 1/4 to 1/10) compared to the starting food. A freeze-dried food thus brings considerable advantages also in transport and storage operations.
If these characteristics are particularly valuable in the industrial field, the final consumer appreciates above all their practicality. In fact, it is sufficient to reconstitute freeze-dried foods with water to obtain a complete, practical and nutritious food. Often consumers, unaware of the complex procedure necessary to obtain freeze-dried foods, raise doubts about their safety. As mentioned at the beginning of the article, foods subjected to freeze-drying maintain the organoleptic characteristics of the raw material unaltered. Furthermore, the fine fragmentation facilitates digestive processes making them especially suitable for feeding children and convalescents. To be sure of the quality of the food it is sufficient to read the label where the ingredients and nutritional characteristics appear in clear letters.
Once the package has been opened, it is advisable to place the remaining product in a sealed package, protected from humidity.
