Question

Which of the following methods is possible to kill bacteria?

(a) Keeping the time constant from previous calculations and maintaining a certain temperature

(b) Bringing the temperature down to a certain value such that the bacteria die in 10 minutes

(c) Keeping the temperature constant and keeping them at that temperature till the time they die

(d) All of the mentioned

The question was posed to me in final exam.

This interesting question is from Principles of Food Preservation by Canning-1 topic in chapter Principles of Food Preservation by Canning and Drying and Principles of Food Concentrates of Food Engineering

Answer 1

The correct choice is (d) All of the mentioned

To elaborate: It is possible to keep the time constant from previous calculations and maintain a certain temperature to kill bacteria. Bringing the temperature down to a certain value such that the bacteria die in 10 minutes is another method used in old times, called thermal death point. Keeping the temperature constant and keeping them at that temperature till the time they die is the latest method used called the thermal death time method.