Blue's the Clue

It was left out in the sun for too long.

It was not kept cool enough.

It was contaminated by the dog.

It was prepared too early in the morning.

Freezing food to kill bacteria.

Using chemicals to sterilize food.

Heating food to inactivate bacteria.

Filtering food to remove impurities.

It uses high-energy electrons or gamma rays to break bacterial DNA.

It cooks the food at very high temperatures to kill all microorganisms.

It removes all moisture from the food, preventing bacterial growth.

It introduces beneficial bacteria that outcompete harmful ones.

They must be solid and firm.

They must be non-compressible.

They must contain high levels of sugar.

They must be able to withstand high temperatures.