- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
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Katherine Zeratsky, R.D., L.D.
Katherine Zeratsky, R.D., L.D.
As a specialty editor for the Food & Nutrition Center, Katherine Zeratsky helps you sort through the facts and figures, the fads and the hype to learn more about nutrition and diet.
A Marinette, Wis., native, she is certified in dietetics by the state of Minnesota and the American Dietetic Association. She has been with Mayo Clinic since 1999.
She is active in nutrition-related curriculum and course development in pediatrics at Mayo Clinic Rochester and nutrition education related to the physiology and recommended intakes for premature infants.
Other areas of interest include breast milk and formula safety, neonatal feeding, and nutrition for breast-feeding mothers.
She graduated from the University of Wisconsin-Madison, served a dietetic internship at the University of Iowa Hospitals and Clinics, and worked as a registered dietitian and health risk counselor at ThedaCare of Appleton, Wis., before joining the Mayo Clinic staff.
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Healthy diets (8)
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Healthy cooking (10)
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- Food poisoning: How long can you safely keep leftovers?
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Healthy menus and shopping strategies (6)
- Sea salt vs. table salt: Which is healthier?
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Nutritional supplements (15)
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- Prenatal vitamins: OK for women who aren't pregnant?
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Question
Food poisoning: How long can you safely keep leftovers?
How long can you safely keep leftovers in the refrigerator?
Answer
from Katherine Zeratsky, R.D., L.D.
According to the Department of Agriculture, you should eat refrigerated leftovers within four days to reduce the risk of food poisoning. If you don't anticipate being able to eat the leftovers within this period of time, freeze them immediately.
Food poisoning — also called food-borne illness — causes abdominal pain, diarrhea, nausea and vomiting. Food poisoning is caused by harmful organisms such as bacteria in contaminated food. Because bacteria typically don't change the taste, smell or appearance of food, you can't tell whether a food is dangerous to eat. So if you're in doubt about a food's safety, it's best to throw it out.
Fortunately, most cases of food poisoning can be prevented with proper food handling. To practice food safety, quickly refrigerate perishable foods such as meat, poultry, fish, dairy and eggs — don't let them sit more than two hours at typical room temperature or more than one hour at temperatures above 90 F (32 C). Uncooked foods, such as cold salads or sandwiches, also should be eaten or refrigerated promptly. Your goal is to minimize the time a food is in the "danger zone" — between 40 F (4 C) and 140 F (60 C) — when bacteria can multiply.
Before eating leftovers, reheat them thoroughly. Reheat leftover sauces, soups and gravies to boiling. If you're using the oven to reheat leftovers, set the temperature no lower than 325 F (163 C) to ensure they're reheated quickly. Because they may not get hot enough, slow cookers and chafing dishes aren't recommended for reheating leftovers. To safely reheat cooked food in a microwave oven:
- Cover foods with a lid or a microwave-safe plastic wrap to hold in moisture and provide safe, even heating. Turn back a corner for the steam to vent.
- After reheating foods in the microwave oven, allow standing time. Then, use a clean food thermometer to check that food has reached 165 F (74 C).
Moldy cheese: Is it unsafe to eat?
- Basics for handling food safely. U.S. Department of Agriculture. http://www.fsis.usda.gov/Fact_Sheets/Basics_for_Handling_Food_Safely/index.asp. Accessed March 3, 2009.
- Foodborne illness: What consumers need to know. U.S. Department of Agriculture. http://www.fsis.usda.gov/Fact_Sheets/Foodborne_Illness_What_Consumers_Need_to_Know/index.asp. Accessed March 5, 2009.
- Food safety: Food storage, preparation & handling. U.S. Department of Agriculture. http://www.fsis.usda.gov/Help/FAQs_Hotline_Preparation/index.asp. Accessed March 3, 2009.
