Freezing is one of the easiest and least time-consuming methods of food preservation. Most foods retain their natural color, flavor, and nutritional value better than other methods of preserving food. However, a freezer can be a major investment and space is limited. If there is an extended power outage, food can be lost. Frozen foods change in texture after thawing.
Freezing does not destroy bacteria., it merely stops their growth temporarily. Spoilage can occur in frozen foods if the freezing does not take place rapidly, or when the freezer temperature gets above 0°F. Be sure to use wide flat containers to freeze the food more rapidly.
When thawing food, remember that freezing does not destroy any spoilage organisms that were present in the food. When frozen foods are thawed slowly at room temperature, the surface warms up to a temperature where the bacteria can grow again even if the center of the food is still frozen solid. For this reason, thaw all foods in the refrigerator. You may have to plan ahead to accomplish this. Frozen foods can be thawed in a microwave on defrost setting. You can also thaw them by running them under COLD water.
Freezing also slows down, but does not kill the enzymes in foods which help in their ripening and maturing processes. Blanching helps protect the texture and quality of vegetables by killing the enzymes. Check publications such as University of Missouri Extension Guide GH1503 for procedure and proper blanching times. Enzymes in fruits can cause browning and loss of vitamin C. Many fruits must be treated with ascorbic acid to prevent the browning.
Pack foods in the form and quantities that will be used for a single meal. It may be difficult to peel, grate, or divide the food later if a different form or smaller amount is needed. Some loose foods can be frozen separately on a cookie sheet or tray and then placed in a freezer bag for more flexibility in amounts used at a time.
Use packaging materials that are air-tight and labeled for freezer use. They should be food grade and durable in the freezer. Pack foods tightly with as little air as possible in the package for better quality retention. Most foods packed in rigid containers require headspace for the food to expand as it freezes. Press all possible air out of flexible packaged foods.
Label each package with the name of the product and date. Other information can be helpful as well. Use freezer tape or self adhesive labels for labeling.