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
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
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
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
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
– 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,
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
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
Source: Beth Reames