Foods in the freezer are becoming a trend in India as well. But are they safe? How long the can a food be kept in the freezer? There are several questions regarding frozen foods as few people understand how freezing protects and affects food.
What Can I Freeze
Almost any food can be frozen except some foods like canned food or eggs in shells. But once the food is taken out of the can it can be freezed. Remember that you may freeze almost any food but the quality after defrosting can get affected. Some foods like cream, sauce, spinach and lettuce don’t freeze well. Meat and poultry should be stored raw as their quality remains better than cooked meat and poultry as moisture is lost during cooking.
Are Frozen Foods Safe
If the temperature is maintained constantly in your freezer at 0 °F then the food is safe, but the quality can get affected by lengthy freezer storage. Freezing slows the movement of the molecules, the microbes enter a dormant stage and the growth of microorganisms that lead to food spoilage and foodborne illness is prevented--- this keeps the frozen food safe.
Are Bacteria and Parasites destroyed by Freezing
Freezing to 0 °F does not destroy microbes -- bacteria, yeasts and molds. It just prevents their growth. After thawing the microbes again become active and start to multiply and grow at about the same rate as microorganisms on fresh food. After the food is removed from the freezer and thawed it must be handled the same way as any other perishable food. Freezing to sub-zero temperatures can destroy trichina and other parasites. However this is not completely dependable and proper cooking must be ensured to destroy trichina and other parasites.
Is the Freshness and Quality of foods maintained with Freezing
If the temperature is maintained constantly in your freezer at 0 °F then the food is safe, but the quality get affected by lengthy freezer storage. In addition the freshness and quality is affected by the condition of food at the time of freezing. If the quality of food is good at the time of freezing than they taste better than foods frozen near the end of their useful life. So when you want to freeze food items make sure that they are of good quality and store at 0° F or lower to maintain quality, vitamin content, color, flavor and texture of the food.
Is the Nutrient Retained in Frozen Foods
Yes, freezing as such does not destroy nutrients. But in some foods like meat and poultry products, the nutrient value can change slightly with freezer storage.
Enzymes Activity of Foods
Enzymes are present in animal food products, vegetables and fruit. These enzymes promote chemical reactions, such as ripening and can also cause deterioration of food quality. Freezing does slow the enzyme activity but does not completely stop it. Enzymes are present in animal food products such as meats or fish or fruits do not harm these foods after freezing. But vegetables are affected by the enzyme activity and hence partial cooking to prevent deterioration is needed. Cook the vegetable partially and then rapidly chill the vegetables prior to freezing and then store in the freezer.
Role of Packaging
Proper packaging is needed to maintain quality of the frozen food and prevent "freezer burn." Meat or poultry can be stored directly in its supermarket wrapping if you intend to use the product in a month or two. However if you want to keep it for a longer period then you should store it in a airtight heavy-duty foil, (freezer) plastic wrap or freezer paper, or place the package inside a (freezer) plastic bag. Other foods that you intend to freeze should be kept in an airtight heavy-duty foil, (freezer) plastic wrap or freezer paper, or place the package inside a (freezer) plastic bag. Meat and poultry don’t need to be washed before freezing. If a food in a vacuum package is accidentally torn in the freezer, it can still be used safely, overwrap or rewrap the food.
What is Freezer Burn
Some food after freezing may appear dry in certain places when you take them out. These are freezer burns. Freezer burns usually appear as grayish-brown leathery spots and they are caused by air contact on the surface of the food. These parts of the food can be cut either before or after cooking the food.
Can the Colour of Food Change
Color of frozen foods can change after storage-- as the bright red color of fresh meat usually turns dark or pale brown on storage. This occurs as a result of lack of oxygen, freezer burn or prolonged storage. Color of poultry usually does not change on freezing, but the bones and the meat near them can turn dark. Color in frozen vegetables and cooked foods usually changes as a result of excessive drying due to improper packaging or prolonged storage.
Should Food be Frozen Rapidly
If you want to freeze a food do it as fast as possible to maintain its quality. Rapid freezing prevents formation of undesirable large ice crystals in the food where as slow freezing leads to formation of large, disruptive ice crystals. During thawing, the ice crystals damage the cells and causes deterioration in the quality of meat. If you have quick-freeze shelf in the freezer use it to freeze foods. When you keep several packets to freeze do not stack them one above the other, spread them out in the freezer as this helps in freezing more rapidly.
Refrigerator Freezers versus Free standing Freezers
No you should not use refrigerator freezers for prolonged storage of any food. The refrigerator freezers should be used for short-term food storage especially if your freezing compartment cannot maintain zero degrees or if the door is opened frequently. Long-term storage of frozen foods should be done in a free-standing freezer set at 0° F or below. Your freezing compartment or freezer should have a thermometer to check the temperature especially if you have power-outs or mechanical problems.
How long can Food be frozen
Freezing keeps almost any food safe for prolonged period. But keeping a food product for long time changes it’s quality. If a food has been in the freezer for a long time and you are not sure about its quality, check the odor, and color after defrosting. If the food smells rancid or appears unpleasant discard it. If in doubt over color and appearance cook and test it, if the taste and texture are good you can use it.
Food Freezing and Power Out
If there is a power out keep the door of the refrigerator and freezer closed as much as possible. If you do not open the door your refrigerator will keep food cold for approximately four hours and a full freezer will maintain optimal temperature for approximately 48 hours.
Defrosting Frozen Food
Safe ways to defrost frozen food are:
In the refrigerator,
In cold water, or
In the microwave
Never defrost out on the kitchen counter, outdoors or on the porch in sun. These methods can spoil the quality of your food and make it unsafe to eat. Plan for slow and safe thawing (such as in the refrigerator, cold water or microwave). Cook the food item immediately after thawing.
Can I restore a food after thawing
If you have thawed the food in the refrigerator, it can be refreezed safely it without cooking, however there may be a loss of quality. Frozen food after thawing and cooking can be freezed again. Cooked foods thawed in the refrigerator can be refreezed as well.
Can Frozen Foods be cooked without thawing
Yes, raw or cooked meat, poultry may be cooked or reheated directly from the frozen state without thawing. But this significantly increases the cooking time.
How can I store food safely
The aim of proper storage is to reduce foodborne illness due to bacteria such as Salmonella, E. coli O157:H7, and C. botulinum. Keeping food item chilled in the refrigerator is at a proper temperatures is one of the best ways to prevent or slow the growth of bacteria such as Salmonella, E. coli O157:H7, and C. botulinum. All perishable foods should be refrigerated or frozen immediately. Never leave foods that need refrigeration more than two hours at room temperature. Make sure your refrigerator temperature is at or below 40° F (4° C) and the freezer temperature is 0° F (-18° C). If a perishable food item was not properly refrigerated, it is advisable to throw it out. The ready-to-eat foods should be used as soon as possible. When you take a food out from the freezer or refrigerator be alert for signs of spoilage. If the looks or smell is suspicious, discard the food.
Always marinate food in the refrigerator as bacteria can grow in food kept at room temperature for marination.
Regularly clean your refrigerator and wipe any spill right away. This helps to reduce the growth of bacteria in your refrigerator.
Keep foods covered in the refrigerator and daily check leftovers for spoilage.
Keep the eggs as well in the refrigerator, rather than in the door, as the temperature in the door is warmer.
Regularly check food kept in your refrigerator for expiration dates. If food is past its "use by" date or if the food looks suspicious, discard it.
Some Freezer Facts
Foods frozen properly and stored in the freezer at 0° F (-18° C) are safe.
Freezing keeps almost any food safe for prolonged period, but the tenderness, flavor, aroma, juiciness, and color can all be affected.
Refrigerator freezers are not for prolonged storage of any food. The refrigerator freezers should be used for short-term food storage only.
If you want to freeze a food, freeze it rapidly to maintain its quality.
If you want to keep a food item stored in the freezer for a longer period then store it in an airtight heavy-duty foil, (freezer)plastic wrap or freezer paper, or place the package inside a (freezer) plastic bag.
Your freezing compartment or freezer should have a thermometer to check the temperature especially if you have power-outs or mechanical problems.
Freezing does not reduce the nutrients content but can affect the color, flavor, aroma, and juiciness.