The freeze-drying machine adopts vacuum drying technology, which retains great nutritional value and is popular among people. What are the advantages and disadvantages of freeze dryer?
1、 Advantages
1. Food drying is carried out at low temperatures (-40 ~ -60℃) and is in a high vacuum state. Therefore, it is very suitable for drying food ingredients with high heat sensitivity and high oxidation resistance, which can effectively maintain the color, aroma, taste, and nutritional composition of fresh food ingredients. For example, after drying spinach, only 7% of the vitamins remain, while freeze-dried spinach accounts for up to 94%.
2. Freeze dried products do not lose their original structure, their shape is not easily changed, and they have extremely high solubility and rehydration properties. The appearance, shape, and taste of food after rehydration will not undergo significant changes, and the rehydration rate can reach over 90%.
3. Freeze dried food is stored under vacuum or filled with nitrogen gas, avoiding light and therefore has a longer shelf life.
2、 Disadvantages
1. Compared with traditional high-temperature drying processes, the processing technology of freeze-dried products is complex and difficult to control.
2. The equipment for producing freeze-dried food is complex and requires a large investment, usually consisting of drying rooms, refrigeration systems, vacuum systems, heating systems, and control systems.
3. The production cost of freeze-dried food is relatively high, and the refrigeration and heating systems require a large amount of energy consumption during the freeze-drying process.
