What is the difference between freezing and deep-freezing? At first glance you might think they are practically synonymous, but they are actually quite different food preservation processes.
The difference is that deep-freezing is an industrial process in which foods are brought to a glacial temperature in a very short period of time. Freezing, on the other hand, is a slower and less refined process that can even be performed with a domestic freezer, though it does not guarantee that the food will keep all of its freshness and flavour.
Deep-freezing occurs so quickly, and at such a low temperature that the ice-crystals that form are minute in dimension. For this reason, once they thaw to room temperature again, they are as close to fresh as possible and maintain their nutritional value. Some types of fruit and vegetables are subject to blanching which slightly reduces vitamin C levels, but in general deep-frozen foods are in optimal condition, sometimes even better than their fresh-picked counterparts.