Process
Raw material
- Typical Freeze Drying factory starts from IQF Fruits (Individual Quick Frozen)
- Cutting/slicing/scoring of frozen fruit
Dehydration process
- Frozen raw material is loaded on trays and transferred into the freeze-dry tunnel
- The drying cycle is controlled by a computer program, where each fruit has its own drying curve (proportion of time / vacuum / temperature)
- During the process, the pressure is lowered close to zero millibar, where the ice crystals starts to sublimate to water vapor
- The whole drying cycle takes between 18-24h, depending on the fruit, water content, cut sizes
- Once the water content of the fruit is reduced to 2-4 %, the, heating is stopped, vacuum is released and trays are unloaded and typically after a short cooling phase packed into intermediate packing (plastic bags) and stored until processed further.
Final product
- Dried fruits are typically sorted manually on tray / transport belt and /or automatic by optical sorting
- Fruits can be sieved into different fractions or milled to powder
- Moisture level below 5%
- Freeze dried fruits = intensive taste & natural colour
- vitamins, minerals, antioxidants are preserved
- Long shelf life at ambient storage temperatures (12-24 months)