Vacuum helps preserve food

Vacuum helps preserve food.
Freeze-drying is achieved using vacuum technology.
There are many ways to extend the shelf life of food. A key step in the oldest smoking and curing methods is air drying, a method that has been used for a long time before freezing, high-temperature cooking, or vacuum packaging. Modern freeze-drying technology is an improvement on traditional drying methods, preventing food spoilage for an even longer period. This process can only be achieved using modern vacuum technology, as freeze-drying requires a vacuum environment. The FrostX freeze dryer is compact and ideal for bakeries and restaurants. It can freeze-dry a variety of fruits, vegetables, herbs, mushrooms, meats, and even ready-to-eat foods.
Freeze-drying process

Freeze-drying is a purely physical process that utilizes the principle of sublimation. In the vacuum environment of the drying chamber, the frozen water sublimates into water vapor. The ice skips the "liquid" state and directly changes from "solid" to "gaseous."
Before the actual drying process, the product must be refrigerated at a low temperature. After refrigeration, the product undergoes drying. The actual drying process takes place in an airtight chamber, where a vacuum pump reduces the pressure to a vacuum level of 1 to 0.5 mbar. The frozen moisture immediately begins to evaporate at a low temperature of -40°C. The water vapor is drawn from the drying chamber to the downstream condenser by the vacuum pump. In this "ice trap," cooled to approximately -50°C, the water vapor sublimates and condenses into ice on the cooling coils. During this process, most of the moisture in the product is removed.
When water sublimates, it absorbs heat from the drying chamber. This process means the temperature inside the chamber will drop, necessitating reheating. It is crucial to add only the same amount of heat absorbed by the water during sublimation to maintain a constant temperature or allow for a slight temperature increase.

The drying chamber is then ventilated to atmospheric pressure, and the dried product with a moisture content of 1-4% is removed for further processing. Ventilation is performed using dry air or an inert gas to prevent the dried product from absorbing moisture from the ambient air.