Let us walk for a while on the slimy side, where, indeed, there is fungus among us. In some cases it is just a nuisance, but certain molds can be hazardous to your health.
According to the U.S. Department of Agriculture, some molds cause allergic reactions and respiratory problems, and a few, under the right conditions, produce poisonous substances called mycotoxins that can make you sick.Worldwide, mold causes great economic losses, destroying crops and shortening food storage time in the home.
So, what to do? Avoid molds where you can; learn how to deal with them when you can't. Here's a guide to what you should know about mold:
By definition: Molds are members of a group of so-called primitive plant-like organisms called fungi, which also includes mushrooms, mildews, yeasts, water molds, slime molds, rusts and smuts. There are more than 400,000 known species. The fungi depend for their food on living or dead organic matter. They are non-motile, so must take up residence or establish themselves on material to survive, thus are often associated with decay and disintegration.
How molds grow: As with most fungi, the body of a mold consists of "root" threads that invade the food it lives on, a stalk that rises above the food, and spores that form at the ends of the stalks. The spores give the mold the color you see. When airborne, the spores spread the mold from place to place like dandelion seeds.
Once a food shows heavy mold growth, the root threads have invaded it deeply. In dangerous molds, the mycotoxins are often contained in and around these threads. In some cases, the toxins have spread throughout the food.
Where mold grows: Molds will grow in almost any food. What they mainly need are high moisture and warm temperatures. Thus foods naturally high in moisture are most susceptible to quick invasion and spoilage by molds. These include soft or watery fruits and vegetables (such as oranges, peaches, tomatoes and squash), many kitchen leftovers, opened canned foods and bakery and dairy products (including cheese, but not butter; butter's solid fat excludes moisture).
Generally, the greater the nutrient content of the food, the quicker the molds will be at it. Although ordinary refrigeration may delay mold invasion, it does not stop molds from growing in some foods. Molds also tolerate salt and sugar better than other food invaders; so you may find molds in refrigerated jams and jelly and on cured, salty meats such as ham, bacon and salami.
Preventing mold growth: Some foods at various stages of processing or preparation for market receive treatment that protects them from molds or at least slows mold growth. Canning prevents mold growth, since molds must have free oxygen to grow. Similarly, freezing stops mold growth. But these processes don't eliminate mold altogether. And consumers need to take several steps to help prevent a mold attack in their homes:
- Cleanliness is important. Mold spores from affected food can build up in your refrigerator, waiting to attack new foods. It's a good idea to 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 on rubber casings with 3 tablespoons of bleach in a quart of water.
- Shop carefully. Quick and careless shopping may mean you unknowingly buy moldy, or about to be moldy, food. With a little practice, you can learn to identify the beginnings of mold or the conditions that make food ripe for spoilage. Check expiration dates, watch out for soft and mushy spots on fruits and vegetables, check stem areas on fresh produce.
Newly purchased food found to be moldy should be returned unused to the store.
- Protect food from invaders. When serving food, keep it covered to prevent exposure to mold spores in the air. Don't leave perishables out of the refrigerator for longer than two hours. Empty opened cans of perishable foods into clean refrigerator dishes and refrigerate promptly. Reseal boxed food as tightly as possible to keep air that contains mold spores out. Cheese and cake keepers with their own covers can protect those foods without excess moisture buildup.
If mold springs up: When you see moldy food, don't sniff the moldy item - that can lead to respiratory trouble. If food is covered with mold, discard it. Put it in a small paper bag or wrap in plastic for disposal in a covered trash can so children and animals don't get into it. Cooking and freezing may stop mold growth, but will not affect the toxins the mold may already have produced.
In trying to save food, remember that the visible evidence of and probably the most extensive damage to food will be at those points where free oxygen is available. But the mold that's visible is only part of the contaminating microorganisms. The hyphae, or vegetating parts, extend below the surface like roots.
If food shows only a small mold spot, follow these guidelines:
- Cheese: Some cheese is made with mold, but you may spot mold that shouldn't be there. In hard block cheeses, cut off at least an inch around and below the mold spot. Keep your knife out of the mold itself. After the "surgery" re-cover the cheese in fresh wrap. Don't try to save individual cheese slices, soft cheese, cottage cheese, sour cream or yogurt.
- Hard salamis and country ham: Use the cheese rule, unless ham is covered with black or brown mold; in that case, discard it. Throw out moldy bacon, hotdogs, sliced lunch meats, meat pies or opened canned ham.
- Smoked turkey: Cut a small mold spot off the surface, using the cheese rule. Throw moldy cooked chicken out.
- Jams, jellies, syrups: Discard any such items showing any mold growth. Experts now feel mold toxins, if present, can spread through this soft material quite rapidly.
- Fruits and vegetables: Cut out small mold spots from the surface of firm fruits and vegetables (cabbage, bell peppers, carrots) but discard soft vegetables (tomatoes, cucumbers, lettuce) showing mold.
- Potatoes: Note any damaged areas on the surface and cut away tissue that is blackened or discolored. It's best to do this before cooking, but you can also do it after cooking.
- Throw away on sight: Discard visibly moldy bread, cake, buns, pastry, corn-on-the-cob, stored nuts, flour, whole grains, rice, dried peas and beans and peanut butter.
Check carefully any food you've had a while that the store or seller sold as "natural." Processed without preservatives, these foods are prone to mold growth.
For more information on mold or the handling of perishable foods, call USDA's Meat and Poultry Hotline, 1-800-535-4555.
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(Additional story)
A musty odor could mean spores are spoiling clothes or other fabrics
In our climate, we don't have the problems with mildew that plague more humid areas. But even here mildew can grow in dark, damp places - on clothes that get wet and left in the wrong places, or in dingy corners of basements and bathrooms.
Mildew is a thin, often whitish growth that springs from mold when the conditions are right. Mildew discolors and eats away at fabrics and other materials, leaving behind a musty odor.
The best way to fight mildew, of course, is to prevent it. Keeping the mildew-prone areas of your household clean is essential. Closets, dresser drawers, basements, bathrooms and crawl spaces should be cleaned regularly. Soil on clothing provides food for mildew growth when proper moisture and temperature conditions prevail.
Controlling dampness is also an important part of any anti-mildew campaign. Condensation of warm, moist air on cooler surfaces can cause basement dampness. Cracks and crevices in the wall can let water through as well.
And always keep your nose primed for musty odors, especially coming from shower stalls and basements. On concrete floors and on tiled walls and floors in bathrooms, cleaning with a dilute solution of sodium hypochlorite or chlorine bleach can be effective in removing mildew and preventing new growth. Soaking a shower curtain in a dilute liquid bleach solution can also prevent mildew.
What about clothes that are attacked by mildew? Badly mildewed fabrics may be damaged beyond repair. However, you can try brushing off as much of the surface mildew as you can (do it outside to prevent the spores from scattering to other surfaces where they could grow). Launder stained items using chlorine bleach, if safe for fabric. Or soak in oxygen bleach and then launder. A mixture of lemon juice and salt, blended to form a paste that can be worked into the fabric, may remove stains.