Freeze-drying uses advanced technology to remove a food’s water content while preserving all of its organoleptic qualities. The food is first quick-frozen, then put in a vacuum that causes ice to sublimate as water vapour. Once their water is removed, fruits and vegetables lose 85 to 95% of their initial weight. The process of drying foods without heating them prevents them from deteriorating: flavour, colour, fibres, and nutritional value are fully preserved.
The end product can be safely stored at room temperature for several years. No refrigeration is needed. Freeze-drying is used to produce survival food kits as well as daily meals for astronauts, soldiers, and long-range explorers. To restore the food’s original qualities, all you need to do is add water.
One of the main benefits of freeze-drying is that fruits and vegetables are picked when they are perfectly ripe and at peak nutritional value – unlike fresh produce at the supermarket when it is sourced abroad. This is often picked unripe and must ripen during transport, under far from ideal conditions.
Freeze-drying is so effective that a number of studies on cancer prevention have been based on freeze-dried foods. One of these, carried out by Dr. Gary Stoner of the Medical College of Wisconsin, has shown that freeze-dried strawberries and raspberries have anticancerous benefits for patients.