Mostly, when people see spots of mould on their bread, they perform all sorts of ‘surgeries’ on the bread in their quest to make that piece of bread appear palatable for consumption. Some slice off the mouldy portion of the bread, heat/toast the remaining portion and eat it. But does this make the bread safe for consumption?
Moulds are fungal microbes which survive in a wide range of habitats; there are a lot of them even floating in air. Mostly, they grow on moist surfaces. Moulds have a wide array of colours; orange, green black, yellow and others. The moulds that grow on bread are the type that grow in a hot (at least 27°C) and humid environment. Nevertheless, these moulds also thrive in cold conditions, therefore; you can’t avoid them completely by putting bread in your refrigerator.
When a spot of mould grows on a piece of bread, it’s like an iceberg; what you see is only a small section of the whole mould. By nature, moulds have long extensions (called hyphae) which grow deep into the food material and may not be visible to your naked eye. These long fibres allow them to digest and absorb nutrients from the food on which they are growing. Also, as they digest and absorb food, they may also release some chemical substances known as mycotoxins into the food on which they are growing. Moulds that grow on apples release the mycotoxin patulin while those that grow on groundnuts and maize release the mycotoxin aflatoxin. Some of these toxins have been found to be carcinogenic (able to cause cancer). Other toxins released by moulds may take advantage of a weak immune system in conditions such as sickness, malnutrition, tiredness or even skin damage to cause some forms of infections like pulmonary infection.
Most moulds on bread are harmless even though some of them are poisonous and can make you very ill. However, the poisonous moulds or their toxins are the not the kind you may be able to identify just by examining your bread. Clearly, it is not enough to cut the mouldy portion of bread off, because there’s a greater probability of leaving long hyphae in the bread as well as the waste products from the digestion of the bread which may pose some health risks when consumed. Additionally, heating/toasting the bread may not completely eliminate or destroy the mould, its toxin or the health risks they pose.
In order to avoid bread from becoming mouldy, store it in a dark, dry place at room temperature. This prevents it from becoming moist. You may freeze your bread as freezing slows down the activity of moulds thereby prolonging the shelf life of the bread.