"Ask Karen"

November 26, 2013

The Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA), hosts a section on their website called “Ask Karen,” (also available in Spanish). In that section you can get questions answered, ask a question or read through the hundreds of questions they have received. This column highlights some common questions and answers about food safety that are particularly popular at this time of the year.

“How long can you keep leftover cooked turkey or chicken in the refrigerator?” It is recommended using cooked turkey within 3 to 4 days. Refrigeration slows but does not stop bacterial growth. There are two completely different families of bacteria: pathogenic bacteria, the kind that cause foodborne illness, and spoilage bacteria, the kind of bacteria that cause foods to deteriorate and develop unpleasant odors, tastes, and textures. Spoilage bacteria can grow at low temperatures, such as in the refrigerator. Some bacteria such as Listeria monocytogenes thrive at cold temperatures, and if present, will grow in the refrigerator and could cause illness.

“Can bacteria grow in the refrigerator?” There are two different families of bacteria: pathogenic bacteria, the kind that cause foodborne illness, and spoilage bacteria, the kind of bacteria that cause foods to deteriorate and develop unpleasant odors, tastes, and textures. Pathogenic bacteria can grow rapidly in the "Danger Zone," the temperature range between 40°F and 140°F. Because they do not generally affect the taste, smell, or appearance of a food, one cannot tell that a pathogen is present. Spoilage bacteria can grow at cold temperatures, such as in the refrigerator. Eventually they cause food to develop off or bad tastes and smells. Most people would not choose to eat spoiled food, but if they did, they probably would not get sick. However, some bacteria such as Listeria monocytogenes thrive at cold temperatures, and if present, will grow in the refrigerator and could cause illness.

“How many times can I reheat foods?” Leftover cooked food may be stored in the refrigerator for up to four days. During this time, you can reheat the leftovers to 165 °F but return any unused portion to the refrigerator within two hours. Because the quality decreases each time food is reheated, it is best to reheat just the amount needed. Cooked foods that cannot be used within four days should be frozen for longer, safe storage.

“Should I wash chicken or other poultry before cooking?” Washing poultry before cooking it is not recommended. Bacteria in raw meat and poultry juices can be spread to other foods, utensils, and surfaces. We call this cross-contamination. Some consumers think they are removing bacteria and making their meat or poultry safe. However, some of the bacteria are so tightly attached that you could not remove them no matter how many times you washed. But there are other types of bacteria that can be easily washed off and splashed on the surfaces of your kitchen. Failure to clean these contaminated areas can lead to foodborne illness. Cooking (baking, broiling, boiling, and grilling) to the right temperature kills the bacteria, so washing food is not necessary. Using a food thermometer is the only sure way of knowing if your food has reached a high enough temperature to destroy foodborne bacteria.

“Can I use a people thermometer for meat and poultry?” Thermometers used to measure human body temperature do not read high enough temperatures for cooking. They are not manufactured to withstand temperatures above 106 °F. Therefore, never use a medical thermometer for cooking.

“Is butter safe at room temperature?” The U.S. Food and Drug Administration (FDA) inspects foods like butter. Butter and margarine are safe at room temperature. However, if butter is left out at room temperature for several days, the flavor can turn rancid so it's best to leave out whatever you can use within a day or two. Margarine, especially soft tub margarines, can separate into oil or water and solids when not kept refrigerated although it will be safe.

“Is it safe if meat was cooked with plastic wrapping left on it?” Sometimes meat or poultry is accidentally cooked with some of the packaging materials. Packaging materials are clearly not intended to be cooked, however if this happens and the packaging materials remain unaltered (that is, do not melt or come apart) the cooked meat will not pose an imminent health hazard. If the packaging materials have melted or changed shape in some other way, do not use the product because harmful chemicals may have leached into the surrounding meat.

For answers to your food preparation questions, you can call 1-888-674-6854. You can also google “Ask Karen” to email a question, chat on line, or find mobile access (free app available). This column is presented by Quinnipiack Valley Health District, the public health department for Bethany, Hamden, North Haven and Woodbridge, 203 248-4528. Happy Thanksgiving to all readers.