At what temperature (in degree Celsius) is milk heated for 15 to 30 seconds to kill microbes in the pasteurisation method?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 70.
In the pasteurization process, milk is generally heated to 70°C (or 72°C) for 15 to 30 seconds and then rapidly cooled to around 4°C. This method, known as the High-Temperature Short-Time (HTST) process, is designed to eliminate harmful microbes (such as bacteria and pathogens) while preserving the milk's nutritional value and taste. The technique was developed by Louis Pasteur in 1864 to enhance food safety.
Purpose: To destroy harmful microbes without significantly affecting the milk's nutritional value or taste.
Why Not the Other Options?
45°C:
-
This temperature is insufficient to effectively kill harmful microbes.
100°C:
-
This is the boiling point of water and is used in sterilization, not pasteurization. Boiling can alter the taste and nutrient content of milk.
20°C:
-
This is room temperature and does not kill microbes or prevent spoilage.