Explain about the Freezing - method of food preservation?

Freezing (-18°C to - 40°C): In freezing, water in food turns into ice and makes unavailable for reactions to occur, and for microorganisms to grow. Most perishable foods like poultry, meats, fish, ice-creams, peas, vegetables, juice concentrates, etc. can be preserved for several months at this temperature. In vegetables, enzyme action may still produce undesirable effects on flavor and texture during freezing. Heating, like blanching, therefore, must destroy the enzymes before the vegetables are frozen.