If your loaf of bread is sprouting a few specks of growth, is it safe to just trim off the unappealing area and consume the rest?
What about fruit or cheese?
Many of us have been confronted by this dilemma when only a small part of food appears ruined. The temptation to cut around the offending area and continue eating your food is strong, particularly if you are trying to cut down on waste. But it might not always be healthy.
The answer to some extent depends on how you balance your approach to a potential health risk versus your desire to avoid wasting food.
Mould on the surface of food usually appears as a white or green area, often fuzzy in texture. It can be widespread or appear to be isolated on just one section.
Unfortunately, it is not just an awful taste you’re risking if you eat mouldy food. Actively growing mould can release toxins into food.
Mould is a fungus with a structure similar to a plant – roots, a stalk and spores. The roots, often invisible to the naked eye, can grow quite deep. The stalk and spores are what you see on the surface.
That means that while you may think you are cutting off the dangerous part of your food, by just excising the mouldy part, there could be a real risk that the roots, which are not visible, remain and could make you sick.
Certain foods are more dangerous than others when it comes to mould.
It is safe to cut the mould out of hard cheese, but you should probably throw your mouldy bread in the bin.
The low moisture content and dense structure of hard cheese means mould will usually survive only on the surface, rather than spread invisibly into the cheese. However, don’t be afraid to make a deep cut into your block of cheese, just to stay on the safe side.
Many other foods, including mouldy bread, are better off thrown away as the mould is more likely to be growing beyond the areas you can see.
Not all moulds are the same. If you eat blue-vein cheese or Roquefort, and think you can handle a little bit of mould without falling sick, you are putting yourself at risk. Those cheeses contain a healthy, edible mould that is introduced during the manufacturing process.
Other types of moulds can be very harmful. Some cause allergic reactions or induce respiratory distress, which is why you should never sniff a mouldy product.
Some moulds produce poisonous substances called mycotoxins, which can cause serious illness, with symptoms including excessive sweating, tremors, muscle weakness, twitching, headache, fever and vomiting.
As mould on our food is so hard to avoid, here are some general guidelines from the US Food Safety and Inspection Service on responding to the problem:
Discard all of these foods, if mouldy:
- Luncheon meat, bacon and hot dogs
- Yoghurt, sour cream and soft cheese
- Soft fruits and vegetables
- Bread and baked goods
- Peanut butter, nuts and legumes
These foods can be saved from mould:
- Hard salami (the dry, aged type) – scrub mould from the surface.
- Hard cheese – cut off at least 2.5 centimetres around and below the mould. Don’t let the knife touch the mould and recover the cheese with fresh wrap.
- Firm fruit and vegetables – small mould spots can be cut off.