Which temperature is effective in killing E. coli in contaminated food?

• A. 185 Fahrenheit
• B. 32 Fahrenheit
• C. 0 Fahrenheit
• D. -20 Celsius

Answer: (A)

High heat destroys E. coli in contaminated food. When food is heated to about 185°F (85°C), the heat denatures bacterial proteins and disrupts cell membranes quickly, killing the cells. This level of heat is well above what is needed to inactivate E. coli and ensures the bacteria don’t survive, even if some heat distribution isn’t perfect.

Freezing or very cold temperatures don’t reliably kill E. coli. They may stop growth or keep bacteria dormant, but many cells can survive freezing and become active again when thawed. That’s why chilling or freezing is used for preservation, not for sanitizing food.

So, heating to 185°F is effective because it delivers enough heat to rapidly inactivate the bacteria, while the other temperatures shown do not guarantee killing them.