Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): HTST Pasteurization is less drastic heat treatment given to milk for its preservation.
Reason (R): In HTST Pasteurization milk is held at a temperature of 72ºC for 15 Seconds.

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

Hint:

HTST pasteurization (\(72^\circ\text{C}\) for 15 seconds) is designed to destroy pathogens in milk while preserving its fresh flavor, unlike UHT processing (\(135\text{--}150^\circ\text{C}\) for 2--5 seconds) which achieves commercial sterility.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Pasteurization is a mild thermal process designed to destroy pathogenic microorganisms in milk, thereby extending its shelf life while maintaining its nutritiol and sensory quality.
High-Temperature Short-Time (HTST) pasteurization is the most common continuous pasteurization method used in the dairy industry.

Step 2: Detailed Explation:
Let us alyze both statements and their relationship:
- Assertion (A): HTST pasteurization is a relatively mild thermal process compared to sterilization or Ultra-High Temperature (UHT) processing.
While sterilization completely elimites all microbes and spores using temperatures above \(100^\circ\text{C}\), pasteurization targets only the most heat-resistant vegetative pathogens (such as *Coxiella burnetii* and *Mycobacterium tuberculosis*) without achieving complete sterility.
This makes it a less drastic heat treatment that preserves milk proteins, enzymes, and flavor.
Thus, Assertion (A) is true.
- Reason (R): The standard operatiol parameters for HTST pasteurization require heating milk continuously to a temperature of \(72^\circ\text{C}\) (specifically \(71.7^\circ\text{C}\)) and holding it at that temperature for at least 15 seconds.
This specific combition of temperature and time is sufficient to kill target pathogens while minimizing thermal damage to the milk.
Thus, Reason (R) is true.
- Relationship: The reason HTST is a less drastic treatment is because it uses a moderate temperature (\(72^\circ\text{C}\)) and a short holding time (15 seconds) compared to more severe thermal processes.
Thus, Reason (R) provides the correct physical explation for Assertion (A).

Step 3: Fil Answer:
Both statements are true, and the Reason correctly explains why the pasteurization process is considered a less drastic heat treatment.
Hence, the correct option is (A).