Nowadays, there are many food preservation technologies, and freeze-drying is one of the commonly used drying technologies. Freeze-drying technology refers to vacuum freeze-drying technology. It is different from frying or baking and spray drying when making powder. Freeze-drying is the process of freezing food. The food is placed in a vacuum environment for sublimation, and the food is dehydrated and dried. According to Diane Barrett, a food science and technology expert at the University of California, Davis, once freeze-dried food is rehydrated, its nutritional value is similar to that of fresh food, retaining the color, aroma, taste, shape, and more than 97% of the nutrients. The ingredients do not require any preservatives and can be stored for a long time at room temperature. At present, this technology has been applied in freeze-dried fruit slices, freeze-dried instant soup, freeze-dried dehydrated seafood and vegetables and other products.
Advantages of freeze-dried food：
✔️Freeze drying is performed at low temperatures, so it is particularly suitable for many heat-sensitive substances. Such as or loss of biological vitality.
✔️When drying at low temperatures, some volatile components in the substance lose very little and the original nutrients are maintained.
✔️During the freeze-drying process, the growth of microorganisms and the action of enzymes cannot proceed, so the original shape can be maintained.
✔️Since it is dried in a frozen state, the volume is almost unchanged, the original structure is maintained, and no concentration occurs.
✔️The dried material is loose and porous and sponge-like. When water is added, it dissolves quickly and completely and returns to its original shape almost immediately.
✔️Since drying is carried out under vacuum with very little oxygen, some easily oxidized substances are protected.
✔️Drying can eliminate more than 95-99% of water, so that the dried product can be stored for a long time without deterioration.
