- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
read biographyclose windowBiography of
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.
More answers
- Water softeners: How much sodium do they add?
- Fiber supplements: Are they safe to take every day?
- Olive oil: What are the health benefits?
- Fat grams, calories or percentages: Which are more important?
- Moldy cheese: Is it unsafe to eat?
- Phenylalanine in diet soda: Is it harmful?
- White whole-wheat bread: Is it nutritious?
- Canned food: How long can you safely keep it?
- Microwaving plastic: Does it release dioxins?
- Stevia: Is it available in the United States?
- Vitamin D: How much is too much?
- Calcium supplements: Do men need them too?
- What is BPA? Should I be worried about it?
- Calcium supplements: Which type is best?
- Thanksgiving turkey: Can you cook it frozen?
- High-fructose corn syrup: What are the concerns?
- Diverticulitis diet: Can certain foods trigger an attack?
- Vitamin D: How much do I need?
- Multivitamins: Do young children need them?
- Buying beef? A guide to choosing the leanest cuts
- Calcium supplements: Should they be taken with meals?
- Low-sodium diet: Why is processed food so salty?
- Taurine in energy drinks: What is it?
- High-protein diets: Are they safe?
- Calories in sushi: What are the low-cal options?
- Vegetable juice: As good as whole vegetables?
- Butter vs. margarine: Which is better for my heart?
- Acai berry products: What are the health benefits?
- Percent Daily Value: What does it mean?
- Coffee and health: What does the research say?
- Detox diets: Do they offer any health benefits?
- Freezing meat: Does it kill harmful bacteria?
- Chocolate: Does it impair calcium absorption?
- Energy drinks: Do they really give me energy?
- Vitamin C: Can too much be harmful?
- Alkaline water: Does it have health benefits?
- Canola oil: Does it contain toxins?
- Dietary supplements vs. food: Which is better?
- E. coli: How can I tell if food is contaminated?
- Roasting nuts: Lower fat by roasting in the shell?
- Yerba mate: Is it safe to drink?
- Water after meals: Does it disturb digestion?
- Ground flaxseed: Better than whole?
- Diverticulitis diet: Should I avoid nuts and seeds?
- Monosodium glutamate (MSG): Is it harmful?
- Canned pumpkin: Better than fresh?
- Smart Balance: Are cholesterol-lowering products safe for everyone?
- Vitamin water: Better than plain water?
- Diet soda: Is it bad for you?
- Microwave popcorn: Is it linked to lung disease?
- Too skinny? How to add pounds safely
- Sea salt vs. table salt: Which is better?
- Caffeine: Is it dehydrating or not?
- Prenatal vitamins: OK for women who aren't pregnant?
- Grape juice: Same heart benefits as wine?
- Diverticulitis diet: What should I eat after an attack?
- Lentils: How do I cook with them?
- see all
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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).
Water softeners: How much sodium do they add?
- 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.
