Because the vacuum freeze-drying is carried out at low temperature and low pressure, and the water is not directly sublimated in the liquid state, the vacuum freeze-dried product can ensure that various nutrients such as protein and vitamins in the food, especially those volatile heat-sensitive components, are not lost, so it can maximize the To maintain the original nutrients, effectively prevent the oxidation of the drying process, the transformation of nutrients and state changes. Freeze-dried products are sponge-like, have no shrinkage, have excellent rehydration, are easy to eat, and have very little water content. After corresponding packaging, they can be stored and transported at room temperature for a long time. Therefore, many special properties are given to its products:
1. The dehydration is relatively thorough, which is conducive to long-term storage.
2. The drying process of the material is completed in a frozen state. Compared with other drying methods, the shrinkage rate of the product is much smaller than that of the fresh material, and the organizational structure and appearance of the raw material are well preserved.
3. There is no surface line, and the air is basically isolated, effectively inhibiting the biological, chemical or physical changes of heat-sensitive substances. The nutrients and active substances in the raw materials are fully preserved, and the natural color and smell of the raw materials are well maintained.
5. Reduce the water content of the product, reduce the weight, and facilitate transportation.
