Ultra low refrigeration means the evaporate temperature is under -60 degree Celsius, which the frozen objects are constantly or rapidly frosted within such range of temperature. However, the central temperature for massive objects such as fish, can solely maintain under -18 degree Celsius. Specifically, both internal and external of massive object can avoid from crystallization so that the bacteria will no longer exist. Crystallization may damage the cells of the fish or massive objects, which causes dehydration and the loss of freshness. 

Currently, the technique for ultra refrigeration has been prevalently used within biotechnology and valuable fishing industries due to the fact that such technique can preserve the frozen objects under its original feature and for longer lifespan.