Food Safety Quiz: Microbial Contaminants

Study Notes

Food: Microorganisms require carbohydrates and proteins, commonly found in meat, poultry, dairy, and eggs.
Acidity: Optimal growth occurs in foods with a neutral to slightly acidic pH (4.6 to 7.5).
Temperature: Ideal growth temperature ranges from 41°F to 135°F (5°C to 57°C).
Time: Microorganisms need at least 4 hours in the temperature danger zone (TDZ) for significant growth.
Oxygen: Some microorganisms need oxygen; others thrive in its absence.
Moisture: High moisture levels, indicated by water activity (aw of 0.85 or higher), are necessary for growth.

Control temperature by refrigerating or freezing food properly and cooking food thoroughly.
Limit food's time in the temperature danger zone (TDZ) to minimize growth.

Foodborne Infections: Caused by eating food with pathogens that grow in the intestines.
Foodborne Intoxications: Result from consuming food containing pre-formed toxins.
Foodborne Toxin-Mediated Infections: Occur when pathogens produce toxins after ingestion.

Contamination can occur person-to-person, through sneeze/vomit exposure, or via dirty surfaces and equipment touching food.

Bacteria are single-celled, living organisms that reproduce quickly under favorable conditions.
They can be found in food, water, soil, animals, humans, and insects.
Some bacteria can survive freezing and may form spores for protection, especially when nutrients are scarce.

Spores can resist heat and survive cooking, allowing bacteria to revert to a growing form when conditions are favorable, such as improper food storage.