The humidity of fresh jujube is about 85%-90%, and the humidity of dried jujube is much lower, about 40%-60%.

Cold storage is a place to store fresh-keeping agricultural products, and its function is to keep the low-temperature environment stable. Thermal insulation performance is usually called thermal insulation. The good thermal insulation structure of the refrigerating room can prevent the cold generated by the refrigerating unit from leaking to the outside as much as possible. On the other hand, it is to minimize the leakage of heat from the outside of the freezer to the inside of the freezer, which is also the main difference between the freezer and ordinary houses.

Cold storage is mainly used for freezing processing and refrigeration of food, medicine and machinery. It keeps the indoor temperature at a certain level through artificial refrigeration. The walls, floors and ceilings of cold storage buildings are paved with thermal insulation materials with certain thickness.

Reduce the external heat transfer of cold storage. In order to reduce the absorption of solar radiation energy, the exterior wall surface of cold storage is generally painted white or light color, so the cold storage building is different from ordinary industrial and civil buildings and has its own unique structure.