Question

5 samples of pasteurized milk from a single lot were analyzed and their total plate counts were (cfu/ml): 25,000; 37,000; 15,000; 45,000 and 20,000.
Which of the following statements are true with respect to n, c and quality of the lot on the basis of the given data:

• A. n=5; c= 2; acceptable
• B. n=5; c=3; satisfactory
• C. n=5; c= 2; satisfactory
• D. n=5; c= 3; unsatisfactory

Hint:

In FSSAI "n, c, m, M" plans:
- All samples below 'm' = Satisfactory.
- Up to 'c' samples between 'm' and 'M' = Satisfactory.
- Any sample above 'M' or more than 'c' samples above 'm' = Unsatisfactory.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
FSSAI sampling plans for pasteurized milk (Total Plate Count) usually define:
-n: number of units comprising the sample (here n=5).
-m: lower limit (Satisfactory/Acceptable).
-M: upper limit (Maximum allowable).
-c: number of sample units allowed to fall between 'm' and 'M'.

Step 2: Detailed Explanation:
For pasteurized milk, the FSSAI standard values for Aerobic Plate Count (APC/TPC) are:
n=5, c=2, m=30,000 cfu/ml, M=100,000 cfu/ml.
Let's analyze the given sample counts:
1. 25,000 (\(< m\))
2. 37,000 (between m and M)
3. 15,000 (\(< m\))
4. 45,000 (between m and M)
5. 20,000 (\(< m\))
Results:
- 3 samples are \(< m\) (Satisfactory).
- 2 samples are between m and M.
According to the plan (c=2), if up to 2 samples are between m and M, the lot is considered "Satisfactory" or "Acceptable" (depending on the terminology used in the specific regulation version). Since c=2 is allowed and we have exactly 2, the lot passes as satisfactory.

Step 3: Final Answer:
The true statement is n=5; c= 2; satisfactory.