The temperature of quick-freezing cold storage is generally below - 30 C, which means that food is rapidly frozen through its maximum ice crystal formation area when the average temperature reaches - 18 C. During the freezing process, food will undergo various changes, such as physical changes, changes in cell tissue, biological and microbial changes, etc. Quick-freezing cold storage is mainly used for low-temperature freezing of food, medicine, medicinal materials, chemical raw materials, etc.

Fast frozen food has the following advantages:

(1) Avoid the formation of large ice crystals between cells.

(2) Reduce the extracellular water analysis and less juice loss during thawing.

(3) The contact time of solute concentration and food tissue, colloid and various components in cell tissue was significantly shortened, and the harmfulness of concentration was reduced to the lowest level.

(4) Rapidly lowering food to the temperature of microbial growth activity is beneficial to resist the growth of microorganisms and their biochemical reactions.

(5) Food stays in freezing equipment for a short time, which is conducive to improving the utilization rate of equipment and continuous production.