Question

Microorganisms are destroyed during which stage of pasteurisation?

• A. Heating milk at 70°C.
• B. Cooling milk to freezing point.
• C. Sudden cooling from 70°C.
• D. Addition of chloride salts.

Answer 1

The correct option is C

Sudden cooling from 70°C.

$\bullet$ Pasteurisation is the method of treating food by applying temperature to a certain point to kill disease-causing organisms without altering the flavor or quality. It is usually done in packaged or non packaged juices and milk.
$\bullet$ Milk is heated at 70°C for around 15 minutes and quickly cooled to 4°C. The cell membrane of the microorganisms in the milk degrades due to the sudden change in temperature getting pathogens destroyed.