Durian freeze-drying technology mainly uses the principle of solid-state sublimation into gaseous state, and processes the durian through freeze-drying equipment. In the process of processing freeze-dried durian, firstly, the durian is pretreated or prepared, and the durian pulp to be technically treated is cleaned, graded and sliced.
The second is the process of cooling and solidification, which is to freeze the water in the durian, so that the water-containing substances and free water in the durian are completely frozen into a solid state, and then the durian is sublimated and dried for the first time, using the physical principle of solid sublimation. Heating at low temperature promotes the decomposition of solid water molecules into water vapor, thereby achieving the purpose of durian dehydration. This sublimation drying process will sublime 90% of the water in the durian pulp.
Finally, the secondary drying process are carried out, and the reprocessing is to use a higher physical temperature to dry the frozen water on the capillary wall of the durian pulp, thereby forming a durian dry that has a longer storage time after freeze-drying. The moisture content of durian pulp in the state is basically below 5%.
The total production proess time can be reduced to 13 hours per batch, since we have done many trial tests and finally optimize the production process.