Freeze-drying is carried out at low temperatures, so it is particularly suitable for many heat-sensitive substances.
Proteins, microorganisms and the like do not denaturate or lose biological vitality.
So it is widely used in medicine.
2. When dried at low temperature, the loss of some volatile components in the substance is very small, which is suitable for some chemical products, drugs and food drying.
3. In the freeze-drying process, the growth of microorganisms and the action of enzymes cannot be carried out, so the original properties can be maintained.
Due to the freezing state of drying, so the volume is almost unchanged, keeping the original structure, will not occur concentration phenomenon.
The dry substance dissolves quickly and completely after water is added, and almost immediately returns to its original character.
Because drying takes place in a vacuum, there is very little oxygen, so some oxidizable substances are protected.
Vii. Drying can eliminate 95-99% of the above water, so that the dried products can be preserved for a long time without deterioration.
Therefore, freeze drying is widely used in the pharmaceutical industry, food industry, scientific research and other sectors.