Prudent Food Storage

B. MOLDS IN FOODS

Molds are fungi like mushrooms and yeast. Also like mushrooms, they reproduce by releasing spores into the air that land on everything, including your food and food storage containers. If those spores begin to grow, they create thin threads that spread through their growing medium. These threads are the roots of the mold fungus, called mycelium. The stalk of a mold fungus is the portion above or on the surface of the food. It produces the spores and gives the mold its color. We've all seen examples of this when we discover a dish of something or other left too long in the refrigerator only to become covered in a mold fuzz.

Molds can grow anywhere they have a growing medium (their food), sufficient moisture and warmth. Some can even grow at refrigerator temperatures, albeit more slowly than they would if it were warmer. These fungi can also withstand more salt and sugar than bacteria, which is why you sometimes find mold in jellies and jams with their high sugar content and on dry cured products like ham or bacon with their high salt content.

In the past, a slight amount of mold was commonly felt to be harmless and the food consumed anyway. For molds that were intentionally introduced, such as the mold in bleu cheese, this is fine. For the unintentional molds, it could possibly be a serious error in judgment. These unwanted molds could be producing toxic substances called mycotoxins which can be very bad indeed. Mycotoxins are produced around the root or mycelium of molds and these mold roots can penetrate deeply into the food. Mycotoxins can survive for a long time and most are not destroyed by cooking. The molds probably best known for this dangerous spoilage are the various Aspergillus species which produces a mycotoxin known as aflatoxin, but there are other dangerous fungi as well, such as the Fusarium molds. Both of the above affect grains and some legumes. See B.3 Molds In Grains and Legumes.

IMPORTANT NOTE: In wet pack foods such as your home canned goodies, molds can do something else as well, possibly with lethal consequences. If they find their way into wet pack acid foods canned by the boiling water bath method, whether by reasons of improper procedure or contamination after the fact, they can consume the natural acids present in the food. The effect of this is to raise the pH of the food in the container, perhaps to the point that it becomes possible for spores of Clostridium botulinum, better known as botulism, to become active and reproduce. For this reason, moldy wet pack foods should be safely discarded. This most deadly kind of food poisoning has an entry of its own in the bacterial spoilage section.

Molds in low acid foods canned by the pressure canning method are equally dangerous and should also be discarded in a safe manner.

B.1 MINIMIZING MOLDS

You can do a number of things to minimize unwanted mold growth in your kitchen, food storage areas and refrigerators. If your kitchen is at all like mine, it is the refrigerator that is going to collect the most fungal growth. This can be dealt with by washing the inside every couple of months with a tablespoon of baking soda dissolved in a quart of warm water. Rinse clean and allow to dry. The black mildew that grows on the rubber door gaskets and other places can be dealt with by wiping down with a solution of three tablespoons of household bleach in a quart of water. I generally use a soft bristle brush for this. A really bad case will not bleach back to a white color, at least it won't for me, but will instead turn pink or red after the bleach has carried out its disinfection mission.

The rest of the kitchen can be kept mold free by keeping the area clean, dry, and spraying occasionally with a product such as Lysol. Patches of mold can be eliminated with the bleach solution used on the refrigerator doors.

Try not to purchase more fresh food than you'll be able to eat in a short period of time. This will keep you from having to deal with the moldy remains that didn't get eaten. If food does go moldy, don't sniff it. This is a good way to give yourself respiratory difficulties if you are at all susceptible to mold allergies. Moldy food should be disposed in such a manner that your animals and children won't be able to get into it. Mycotoxins are every bit as bad for your animals as they are for you.

Obviously, you don't have to throw out everything that shows a spot of mold on it. Some foods can be safely dealt with and still partially saved if they show signs of fungal growth. Below is a set of guideline from M. Susan Brewer, Ph.D., R.D., a specialist in food safety. Her articles and works are found in many state university extension services publications lists.

If the food shows even a tiny mold spot, follow these guidelines:

1. Hard or firm foods with tiny mold spots can be trimmed; cut away the area around the mold (at least an inch) and rewrap in clean wrap. Make sure that knife does not touch the mold.
   
   TRIM:
   Hard Cheese (Cheddar, Swiss, etc.)
   Bell Peppers, Carrots, Cabbage
   Broccoli, Cauliflower, Brussels Sprouts
   Garlic, Onions
   Potatoes, Turnips
   Zucchini
   Apples, Pears
   


2. Soft foods such as cheese slices, cream cheese, sour cream and yogurt should be thrown away.
   
   TOSS:
   Soft Cheeses, (Mozzarella, Brie, etc.)
   Sour Cream, Yogurt, Cottage cheese
   Bacon, Hot dogs, Sliced lunch meats
   Meat pies
   Opened canned ham
   Most left-over food
   Bread, Cakes, rolls, flour, pastry
   Peanut butter
   Juices, berries
   Jam, Jellies, Syrups
   Cucumbers, Tomatoes
   Spinach, Lettuce, other leafy vegetables
   Bananas, Peaches, Melons
   Corn-on-the-cob
   Stored nuts, whole grains, rice
   

Updated: 9/18/96; 4/16/97; 7/21/97; 10/20/97; 9/15/98; 11/02/99; 12/01/03

Copyright © 1996, 1997, 1998, 1999, 2003. Alan T. Hagan. All rights reserved.

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