Question

What is used to separate microorganisms from milk?

• A. Pasteurizer
• B. Bactofuge
• C. Homogenizer
• D. Lactometer

Hint:

Bactofugation is widely used in cheese-making to remove anaerobic spore-formers like Clostridium tyrobutyricum, preventing the defect known as "late blowing."

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Microorganisms and their highly resilient spores have a higher density than the liquid phase of milk (milk plasma).
This physical difference in density allows for mechanical separation using centrifugal force without relying solely on thermal treatment.

Step 2: Detailed Explanation:
A bactofuge is a specialized, high-speed hermetic centrifuge designed specifically for the dairy industry.
Because bacterial cells and bacterial spores (such as Bacillus and Clostridium species) have a higher density than milk fat and protein micelles, they migrate to the periphery under intense centrifugal force.
This heavy phase, containing the concentrated microorganisms, is continuously discharged as "bactofugate."
Pasteurizers use heat to destroy pathogenic microorganisms but do not mechanically separate them from the milk.
Homogenizers break down fat globules but do not remove cells.
Lactometers are simple glass instruments used to measure the specific gravity of milk to detect water adulteration.

Step 3: Final Answer:
The centrifugal separator used to remove bacteria and bacterial spores from milk is the bactofuge.