Some bacteria have the ability to form spores. A spore is like a protective coating or outer layer. In spore form, bacteria are able to survive adverse conditions such as cooking, no moisture and chemicals (i.e. disinfectants).
Bacteria can form spores when high-risk food is left in the danger zone for too long. That’s the reason that cooling food quickly and getting it into the fridge or freezer is important.
Cooking doesn’t kill bacteria in spore form. They will survive and then the bacteria will multiply again when the conditions are favourable. The key control here is, don’t let spores form in the first place. Minimise the time that high-risk food is in the danger zone.
3 spore forming bacteria:
- Clostridium perfringens: associated with cooked meat products.
- Clostridium botulinum: associated with canned, bottled and vacuum-packed products.
- Bacillus cereus: associated with cooked rice and rice dishes.
Toxins are poisons released by some bacteria. You can’t see them. They do this either into the food, these are called exotoxins or inside us once we’ve eaten the food (endotoxins). Once inside us, they attack our digestive and nervous systems. Toxins can cause vomiting and diarrhoea and, in some cases, can lead to death. Toxins are not killed by heat so to prevent them forming you need to minimise the time that high-risk food is in the danger zone.
