Freeze-drying is a very gentle dehydration process used for preservation of high quality foods.
During the 1950s, industrial freeze-drying of foods began. Coffee was one of the first freeze dried food products to be produced, but now vegetables, fruits, meats, fish, dairy products, herbs and food flavourings can be successfully freeze dried. The Incas even used a crude form of freeze-drying by leaving potatoes to freeze overnight and then stomping out the ice crystals in the morning.
The final freeze-dried food typically contains between 1% and 4% moisture. Final food products are nitrogen sealed and packed. They can be stored between 6 months and 3 years in polybags and 25 years or longer in cans.
Freeze-dried foods possess superior quality as compared with food dehydrated by other methods. The high quality is due to the absence of a liquid phase, as well as the low temperature of the process. Freeze-drying preserves flavor, color, and appearance, while minimizing thermal damage to heat-sensitive nutrients. In addition, the texture is well preserved due to the process occurring in solid state. Freeze-dried products are typically crisper and have rehydration ratios four to six times higher than conventional air-dried foods. Other key benefits of freeze-drying include the high recovery of volatiles, retention of structure and surface area, high yield, long shelf life, and reduced weight for storage, shipping, and handling.
Since freeze-dried food is preserved without using heat, the nutrients are almost perfectly preserved. Most of the nutritional benefits of the freeze-dried products remain intact. Nutrients are reduced only by the process of sublimation when some of them are lost with the water that evaporates. Nevertheless, 98% of all nutrients are maintained.
Food Types Suitable For Freeze-Drying
Fish and Seafood
Are you looking for a healthy and non extra added sugar fruit snack? Try freeze dried fruits and let us know your experience!