Spoilage bacteria are microorganisms too small to be seen without a microscope that causes food to deteriorate and develop unpleasant odours, tastes, and textures. These one-celled microorganisms can cause fruits and vegetables to get mushy or slimy, or meat to develop a bad odour.
Bacteria and various fungi are the cause of spoilage and can create serious consequences for the consumers, but there are preventive measures that can be taken.
Bacteria are responsible for the spoilage of food. When bacteria break down the food, acids and other waste products are generated in the process.[2] While the bacteria itself may or may not be harmful, the waste products may be unpleasant to taste or may even be harmful to one's health.[3] There are two types of pathogenic bacteria that target different categories of food. The first type is called Clostridium botulinum and targets foods such as meat and poultry, and Bacillus cereus, which targets milk and cream. When stored or subjected to unruly conditions, the organisms will begin to breed apace, releasing harmful toxins that can cause severe illness, even when cooked safely.[4]
Fungi have been seen as a method of food spoilage, causing only an undesirable appearance to food, however, there has been significant evidence of various fungi being a cause of death of many people spanning across hundreds of years in many places through the world. Fungi are caused by acidifying, fermenting, discolouring and disintegrating processes and can create fuzz, powder and slimes of many different colours, including black, white, red, brown and green.[5]
Mould is a type of fungus, but the two terms are not reciprocal of each other; they have their own defining features and perform their own tasks.[6] Very well known types of mould are Aspergillus and Penicillium, and, like regular fungi, create a fuzz, powder and slime of various colours.[7]