Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Thermoduric and thermophilic bacteria can survive pasteurization
Reason (R) : Thermoduric and thermophilic bacteria are able to survive pasteurization because the milk shields them from high temperatures
In light of the above statements, choose the correct answer from the options given below:

• A. Both (A) and (R) are true and (R) is the correct explanation of (A)
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
• C. (A) is true but (R) is false
• D. (A) is false but (R) is true

Hint:

Thermoduric survival is a result of cell physiology (e.g., spore formation or specialized cell wall structures), not physical shielding by the milk. Therefore, (A) is true, but (R) is false.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Thermoduric and thermophilic microorganisms are characterized by their ability to survive or grow at elevated processing temperatures, posing challenges for pasteurized dairy products.

Step 2: Detailed Explanation:
- Assertion (A): Thermoduric bacteria (such as Microbacterium or Bacillus spores) can survive pasteurization temperatures, and thermophilic bacteria (such as Streptococcus thermophilus) can grow at these elevated temperatures. Thus, Assertion (A) is true.
- Reason (R): Their heat resistance is due to their inherent cellular characteristics (such as heat-resistant endospores, specialized heat-stable proteins, or membrane lipids), not because the milk physically "shields" them. During pasteurization, heat is distributed uniformly throughout the liquid, exposing all bacteria to the treatment temperature. Thus, Reason (R) is false.

Step 3: Final Answer
Since the Assertion is correct but the Reason is false, the correct option is (C).