Question

Given below are two statements:
Statement (I): Moseley count is a sterility test that determines post processing contamination.
Statement (II): Moseley count is determined by taking the count after incubating the samples at 30°C for seven days.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true
• B. Both Statement (I) and Statement (II) are false
• C. Statement (I) is true but Statement (II) is false
• D. Statement (I) is false but Statement (II) is true

Hint:

To remember the Moseley Test parameters:
- Milk storage: 7.2°C for 5 to 7 days (simulates refrigerated distribution).
- Agar plate incubation: 30°C or 32°C for 48 hours (standard mesophilic plate count).
It is a post-pasteurization contamination test, not a sterility test.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The Moseley Keeping Quality Test is a microbiological method used in the dairy industry to predict the shelf life of pasteurized milk.
It is designed to detect post-pasteurization contamination, particularly by psychrotrophic bacteria that can grow under refrigeration.

Step 2: Detailed Explanation:
Let us analyze both statements:
-Statement (I): "Moseley count is a sterility test..."
This statement is incorrect.
A sterility test is used to confirm the complete absence of viable microorganisms in sterile products, such as UHT-treated or autoclaved milk.
Pasteurized milk is not sterile; it contains surviving thermoduric vegetative cells and bacterial spores.
Therefore, the Moseley test is a keeping quality or shelf-life prediction test for pasteurized products, not a sterility test.
-Statement (II): "Moseley count is determined by taking the count after incubating the samples at 30°C for seven days."
This statement is incorrect.
In the Moseley test, the packaged milk container is incubated at a refrigerated temperature of 7.2°C (or 5°C) for 5 to 7 days.
This low-temperature incubation allows any post-pasteurization psychrotrophic contaminants to multiply.
After this storage period, the milk is plated using the Standard Plate Count (SPC) method, and the plates are incubated at 30°C or 32°C for 48 hours to count the colonies.
Incubating the milk samples themselves at 30°C for seven days would cause rapid souring and spoilage, rendering the test useless.
Thus, both Statement (I) and Statement (II) are false.

Step 3: Final Answer:
Both Statement (I) and Statement (II) are false, which corresponds to Option (B).