Biology · Kingdom Prokaryote
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Milk is pasteurized by heating at:
- A
100°C
- B
100°C for 30 min
- C
71°C for 15 min and 62°C for 32 min
- D
71°C for 32 min and 62°C for 15 sec
Pasteurization is a food processing method where a mild heat treatment is applied to food to kill harmful bacteria (pathogens) and extend shelf life. In the pasteurization of milk, the milk is either heated to 71°C for 15 seconds or 62°C for about 30 minutes.
100°C is incorrect since boiling milk is not the same as pasteurizing it. As stated above, pasteurization involved mild heat, boiling at 100°C would just be overkill. Therefore, A is incorrect.
B is also incorrect since boiling milk for a specified time (30 min) is also not the same as pasteurizing it, which involves mild heat. Therefore, B is also incorrect.
This option has a typo. It should be 15 seconds instead of 15 minutes at 72°C. Besides that error, this answer is correct, as stated above so C is the correct answer.
In this option, the times are correct but they are with the wrong temp, i.e. the times are inverted. Therefore, D is incorrect.
Tagged under Biology · Kingdom Prokaryote · 2005