Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Standardization practice in dairy industry is unsafe from microbiological point of view
Reason R : The separation is carried out at around $40^{\circ}\text{C}$ which is a congenial temperature for microbial growth and the cream and skim milk obtained, if used for standardization, would seed high number of microorganisms}
In light of the above statements, choose the correct answer from the options given below

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

Hint:

To prevent microbial growth during separation, modern dairy processing plants often use cold-milk separators that operate at temperatures below $10^{\circ}\text{C}$.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Standardization adjusts the fat and solids-not-fat (SNF) content of milk to meet regulatory requirements.
This process uses centrifugal cream separators, which can present microbiological risks depending on processing temperatures.

Step 2: Detailed Explanation:
In dairy processing, centrifugal separation is often performed at warm temperatures, around $40^{\circ}\text{C}$.
This temperature reduces milk viscosity and increases fat separation efficiency.
However, $40^{\circ}\text{C}$ is within the optimal growth range for mesophilic foodborne pathogens and spoilage organisms.
If separation takes place at this temperature, rapid bacterial growth can occur.
The resulting cream and skim milk can contain high microbial loads.
When these fractions are used to standardize subsequent batches of milk, they seed the product with a high initial microbial count.
This high initial load can compromise pasteurization efficiency and reduce shelf life.
This risk makes the warm standardization step a microbiological hazard, validating both Assertion A and Reason R.

Step 3: Final Answer:
Both A and R are true, and R is the correct explanation of A.