The so-called pre-cooling mainly refers to a process in which various types of goods such as food can be stored in the cold storage from normal temperature to 0°C, or close to the temperature of the storage cold storage. In this process, the rapid cooling process before cooling or rapid freezing is called pre-cooling.

The purpose of pre-cooling: the pre-cooled products are put into the cold storage to better extend the preservation time and reduce the electricity consumption of the cold storage at the same time.

According to the state of the room after pre-cooling, there are several common cooling states of cold storage pre-cooling:
1. Pure temperature cooling.
2. It is used in applications where certain liquids need to reach a certain temperature. Such as cooling fruits and vegetables, various foods, liquids, etc.
3. This kind of pre-cooling is only a decrease in the temperature of the item, but the entire physical state does not change, but the heat of the item itself is weakened.
4. Solidification and cooling.
6. This kind of pre-cooling is mostly used for fats, such as animal oil, vegetable oil, margarine, chocolate and so on. Refers to the process of a substance changing from a liquid to a solid state, and the physical state has changed.
7. Precipitate and cool.
This cooling and pre-cooling method is mostly used to process juice, brine, oil, acetone, paraffin, etc. It means that one or more liquid components solidify and precipitate when the liquid is cooled.

In order to extend the shelf life of fruits and vegetables and reduce the loss in transportation and circulation, pre-cooling is essential. Only through pre-cooling can the cooling play a greater role. Because fruits and vegetables are affected by the external environment such as temperature when they are picked, the surface temperature is high, the breathing is strong, and the continuous release of heat will cause the surrounding temperature to be higher, which will cause a large amount of water to evaporate and loss of nutrients. Pre-cooling can greatly avoid this situation.

The significance of pre-cooling various goods:
Take fruits and vegetables as an example. Fruits and vegetables are alive for a certain period of time after being picked in the field. They will continue to breathe heat and affect the freshness of fruits and vegetables. If they are not treated at low temperature, they will quickly deteriorate. To extend the shelf life of fruits and vegetables, pre-cooling is essential.
Fruit and vegetable pre-cooling is a process in which fresh fruits and vegetables after harvest are quickly removed from field heat before being transported, stored or processed, and cooled to a predetermined temperature.
Only through pre-cooling can the cooling play a greater role. Fruits and vegetables are affected by the external environment such as temperature and themselves when they are picked. The outer surface temperature is high and accompanied by strong breathing. The continuous release of heat will cause the surrounding temperature to be higher, which will cause a large amount of water to evaporate and nutrient loss. Pre-cooling can greatly avoid this situation, which is the very important meaning of pre-cooling.