Q: Does freezing kill bacteria in food? Does it destroy nutrients? Am I better off avoiding frozen food and eating only fresh?
A: Freezing food does not kill most microorganisms, but puts them in a dormant state. Though frozen food cannot spoil if it stays frozen, it's only as safe as it was at the time it was frozen. Thus, when you thaw frozen foods, especially meats and fish, you should cook them to the same degree as you would fresh foods.
Frozen fruits and vegetables retain their nutrients almost as well as their fresh counterparts, provided they are quick-frozen, packed in airtight containers and kept frozen during shipping and at the market. Any kind of processing destroys some vitamins. But fresh foods also lose vitamins, especially if they are not properly handled, or if they sit in the market or your refrigerator too long. If vegetables are quick-frozen on site immediately after harvesting, they may have more vitamins than fresh ones transported from distant states or other countries.
Frozen fruits, vegetables, meats and fish may or may not taste as good as fresh, but the difference in nutrition is slightfrozen foods will still have plenty of vitamins.
Don't buy packages with ice crystals or other signs of melting and refreezing. Buy frozen foods just before checking out, and take them straight home. It's often economical as well as convenient to freeze your own meats, casseroles and other foods at home. Wrap them in airtight plastic or put them in a freezer container to maintain flavor and quality. Label and date what you freeze and, for best quality, try to use within a few months. Keep foods frozen at 0°F. (-18°C.).
Adapted from The University of California, Berkeley Wellness Letter (February 2012)