Freezing rate refers to the rate of temperature decline or the forward rate of ice peak at a certain point in food materials. According to the speed of food freezing, the food freezing process can be divided into slow freezing, fast freezing and ultra fast freezing.
Ice peak advance speed
The advance speed of ice peak refers to the distance from the food surface to the inside of the frozen layer at - 5 ℃ within a unit time. The unit is cm/h. It is often called the linear average freezing speed. This method was first proposed by German scholar Planck, who took - 5 ℃ as the ice peak surface of the frozen layer and divided the freezing rate into three levels:
Fast freezing 5~20 cm/h;
Medium speed freezing 1~5 cm/h;
Slow freezing 0.1~1 cm/h.