Nutritionist Looks At Good And Bad Mold On Food

Elizabeth S. Reames  |  12/22/2005 11:23:37 PM

If these cheese cubes had mold on them, these partiicularly cheeses would be unsafe to eat. Some of the mold seen in and around other cheeses, however, is safe to eat, because it is part of the production process.

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When you see mold on food, is it safe to cut off the moldy part and use the rest? For most foods the answer is no, according to the U.S. Department of Agriculture.

LSU AgCenter nutritionist Dr. Beth Reames explains that molds are microscopic fungi that live on plant or animal matter. When a food shows heavy mold growth, "root" threads have invaded it deeply. In dangerous molds, poisonous substances are often contained in and around these threads. In some cases, toxins spread throughout the food may cause allergic reactions and respiratory problems.

A few molds, in the right conditions, produce mycotoxins, poisonous substances that can make people sick. Mycotoxins are found primarily in grain and nut crops, but are also known to be on celery, grape juice, apples and other produce.

Reames says that although most molds prefer higher temperatures, they can grow at refrigerator temperatures. Molds also tolerate salt and sugar and can grow in refrigerated jams and jelly and on cured, salty meats – ham, bacon, salami and bologna.

Not all molds are dangerous, Reames points out. For example molds are used to make certain kinds of cheeses. Roquefort, blue, Gorgonzola and Stilton cheeses have blue veins of mold throughout the cheese. Brie and Camembert have white surface molds. Other cheeses have both an internal and a surface mold.

For hard cheeses in which mold is not part of the processing, it is safe to remove the mold and eat the cheese. USDA recommends cutting off at least 1 inch around and below the mold spot. Be sure to keep the knife out of the mold itself so it will not cross-contaminate other parts of the cheese. After trimming off the mold, re-cover the cheese in fresh wrap. Mold generally cannot penetrate deep into the product.

Discard soft cheeses such as Brie and Camembert if they contain molds that are not a part of the manufacturing process. Molds that are not a part of the manufacturing process can be dangerous. Infected soft cheeses, such as cottage, cream cheese, Neufchatel and crumbled, shredded and sliced cheeses, should be discarded. Such foods with high moisture content can be contaminated below the surface.

Hard salami and dry-cured country hams normally have surface mold. Some salamis have a characteristic thin, white mold coating which is safe to consume; however, they shouldn’t show any other mold. Dry-cured country hams normally have surface mold that must be scrubbed off before cooking.

Small mold spots can be cut off fruits and vegetables with low moisture content such as cabbage, bell peppers, carrots, etc. Cut off at least 1 inch around and below the mold spot. Keep the knife out of the mold itself so it will not cross-contaminate other parts of the produce. Discard fruits and vegetables with high moisture content that can be contaminated below the surface.

Reames says molds also can thrive in high-acid foods like jams, jellies, pickles, fruit and tomatoes. These microscopic fungi, however, are easily destroyed by heat processing high-acid foods at a temperature of 212 F in a boiling water canner for the recommended length of time.

Discard jams and jellies with mold. The mold could be producing a mycotoxin. Discard all other food with molds. Foods with high moisture content or that are porous can be contaminated below the surface.

Reames says cleanliness is vital in controlling mold, because mold spores from contaminated food can build up in your refrigerator, dishcloths and other cleaning utensils.

– Clean the inside of the refrigerator every few months with 1 tablespoon of baking soda dissolved in a quart of water. Rinse with clear water and dry. Scrub visible mold (usually black) on rubber casings using 3 teaspoons of bleach in a quart of water.

– Keep dishcloths, towels, sponges and mops clean and fresh. A musty smell means they’re spreading mold around. Discard items you can’t clean or launder.

– Keep the humidity level in the house as low as practical – below 40 percent, if possible.

Reames also says to examine food carefully before you buy it. Check food in glass jars, look at the stems on fresh produce and avoid bruised produce.

Examine meats carefully. Fresh meat and poultry are usually mold free, but cured and cooked meats may not be.

When serving food, keep it covered to prevent exposure to mold spores in the air. Use plastic wrap to cover foods you want to stay moist – fresh or cut fruits and vegetables and green and mixed salads.

Empty opened cans of perishable foods into clean storage containers and refrigerate them promptly. Don’t leave any perishables out of the refrigerator more than two hours. Use leftovers within three to four days so mold doesn’t have a chance to grow.

When you handle foods with mold, Reames advises not to sniff the moldy item. This can cause respiratory trouble. If food is covered with mold, discard it. Put it into a small paper bag or wrap it in plastic and dispose in a covered trash can that children and animals can’t get into.

Clean the refrigerator or pantry at the spot where the food was stored. Check nearby items the moldy food might have touched. Mold spreads quickly in fruits and vegetables.

For related food safety and nutrition information, contact the FCS agent in your parish or click on the Family and Home link on the LSU AgCenter home page, at www.lsuagcenter.com.

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On the Internet: LSU AgCenter: www.lsuagcenter.com

Source: Beth Reames (225) 578-3929, or breames@agcenter.lsu.edu

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