quick freezing and freezing are two different food refrigeration technologies. the main difference between them lies in freezing speed and temperature.
1. freezing: freezing is to place food in a freezing environment to gradually reduce its temperature until it reaches a temperature below the freezing point.
typical freezing temperature is -18°c. during the freezing process, the moisture inside the food will gradually crystallize to form ice crystals, but the freezing speed is slow.
this results in larger ice crystals, which may damage the cell structure of the food.
for example: put fresh grapes into the freezer for freezing, and the temperature gradually drops to -18°c. the entire process may take several hours or even longer.
during this process, the water inside the grapes will gradually crystallize to form larger ice crystals, which may destroy the cell structure of the grapes and affect the taste and texture.
2. quick freezing: quick freezing is to quickly place food at extremely low temperatures to quickly freeze the surface and interior of the food, thereby forming very small ice crystals.
typical quick freezing temperatures are -30°c to -40°c, or even lower. quick freezing has the characteristics of rapid cooling, which can quickly reduce the temperature of food in a very short period of time.
for example: put fresh grapes into quick-freezing equipment for quick-freezing, and the temperature is quickly reduced to -30°c to -40°c. the whole process may only take a few minutes.
during this process, the water inside the grapes quickly crystallizes to form very small ice crystals, reducing damage to the cell structure and thus maintaining the taste and texture of the grapes.
in summary, quick freezing has a faster cooling rate and lower freezing temperature than freezing. quick freezing can better maintain the texture, taste and nutritional value of food.
of course, different ingredients may require different quick-freezing temperatures and times to achieve the best preservation effect.