- 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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Nutritional supplements (15)
- Vitamin water: Better than plain water?
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Question
Moldy cheese: Is it unsafe to eat?
If a piece of cheese has mold on it, should I throw the cheese away or can I cut off the moldy part and eat the rest of it?
Answer
from Katherine Zeratsky, R.D., L.D.
The answer depends on the type of cheese. Molds are microscopic organisms that have thread-like roots that burrow into the foods they grow on. Most molds are harmless. Molds are even used to make some kinds of cheese, such as Roquefort, Gorgonzola, Brie and Camembert. These molds are safe to eat.
But mold on cheese that's not part of the manufacturing process can also harbor harmful bacteria, such as listeria, brucella, salmonella and E. coli. With hard and semisoft cheese, you can cut away the moldy part and eat the rest of the cheese. Keep the knife out of the mold itself so that it doesn't cross-contaminate other parts of the cheese. Cut off at least one inch around and below the moldy spot. With soft cheeses, however, the mold cannot be safely removed so they should be discarded. The same goes for any cheese that's shredded, crumbled or sliced.
| Moldy cheese? What you should do. | ||
|---|---|---|
| Type of cheese | Do not eat — discard | Safe to eat — after mold is removed |
| Any shredded, crumbled or sliced cheese | X | |
| American | X | |
| Asiago | X | |
| Baby Swiss | X | |
| Blue cheese | X | |
| Brie | X | |
| Camembert | X | |
| Cheddar | X | |
| Chevre | X | |
| Colby | X | |
| Cottage cheese | X | |
| Cream cheese | X | |
| Feta | X | |
| Gorgonzola | X | |
| Gruyere | X | |
| Monterey Jack | X | |
| Mozzarella | X | |
| Muenster | X | |
| Neufchatel | X | |
| Parmesan | X | |
| Ricotta | X | |
| Romano | X | |
| Roquefort | X | |
| Stilton | X | |
| Swiss | X | |
Source: Adapted from U.S. Department of Agriculture, 2006.
To prevent mold growth on cheese, follow these tips:
- Keep cheese and cheese dishes covered with plastic wrap.
- Always refrigerate cheese. Don't allow cheese to sit at room temperature for longer than two hours.
Also, don't eat cheese made from unpasteurized (raw) milk. Raw milk and cheeses may contain harmful bacteria and aren't safe to eat, drink or use in cooking.
Next questionCanned food: How long can you safely keep it?
- Food safety: Foodborne illness. U.S. Department of Agriculture. http://www.fsis.usda.gov/Help/FAQs_Hotline_Illness/index.asp. Accessed Nov. 19, 2008.
- Molds on food: Are they dangerous? U.S. Department of Agriculture http://www.fsis.usda.gov/Fact_Sheets/Molds_On_Food/index.asp. Accessed Nov. 19, 2008.
- The safe food chart: Dairy and raw egg products. U.S. Food and Drug Administartion. http://www.cfsan.fda.gov/~dms/fttmilk.html. Accessed Nov. 19, 2008.
