Katadyn Group

Food dehydration is the oldest method of increasing the shelf life of foods. For millennia, humanity has known that freshly harvested foods will not be spoiled if they are sun-cured. Such dehydrated foods used to be vital for survival during the wintertime, when food supplies were scarce.

Later on, it was found that the dehydration process could be accelerated and further improved by additional heating. Today, state-of-the-art technologies offer new and more advanced approaches to preserving foods. Freeze-drying or vacuum evaporation guarantee a longer shelf life than any other method of preservation.

Put simply, the freeze-drying process can be described as follows:

1. For freeze-drying, only the very best foods are selected. All ingredients are subjected to rigorous quality checks and official monitoring.

2. Fresh or cooked instant meals are flash-frozen in order to preserve their fresh taste, color, and texture – and especially their nutritional value.

3. Then the frozen product is transferred to a vacuum chamber in which a special physical property of water is utilized. In a vacuum, frozen water will be abruptly transformed from the solid to the vapor state (sublimation), allowing the water to be removed from the food.

4. When the foods leave the vacuum chamber, they will have lost up to 90% of their weight and volume and are now ready for being packaged in airtight and watertight cans.

5. During canning, the oxygen contained in the can is replaced by nitrogen. The can is hermetically sealed in order to maintain the high quality of the foods.

6. When the process is reversed by adding hot or cold water to the freeze-dried foods, the foods are restored to their original condition. The freeze-drying process allows a longer shelf life to be achieved than with any other method of preservation.