Types of bacteria in relation to oxygen:
- Aerobic bacteria: They develop only in the presence of oxygen
- Anaerobic bacteria: they grow inside the food when no oxygen is present. Improperly preserved home-canned foods are a common source of botulism. Home-canned items cannot be used in foodservice.
- Facultative anaerobic-aerobic bacteria: They can develop in the absence or presence of oxygen. They will contaminate all foods.
Practical consequences:
- Vacuum packaging is not enough. It can inhibit the development of aerobic bacteria, but it must be kept out of the Danger Zone.
- When foods are improperly processed and then stored at room temperature in airtight conditions such as cans, bottles, or immersed in oil, anaerobic spores may survive and grow.
- Sufficient heat treatment should be applied to preserves to destroy anaerobic germs.
- Do not let broths and the dishes in sauce cool down at room temperature. Cool them quickly or maintain them at a temperature above the danger zone.
