Question

P\(_{\text{H}}\) of normal fresh milk is between

• A. 6.1 to 6.3
• B. 7.1 to 7.3
• C. 6.0 to 6.1
• D. 6.6 to 6.8

Hint:

Remember that fresh milk is slightly acidic, with a pH just below neutral (7.0). Any significant deviation from the 6.6-6.8 range indicates a problem: lower pH suggests bacterial spoilage, while higher pH (alkaline) can be a sign of mastitis.

Answer 1

The Correct Option is D

Step 1: Concept Overview:
The question concerns the typical pH range of fresh milk. pH measures acidity/alkalinity; 7 is neutral, values below 7 are acidic, and values above 7 are alkaline.
Step 2: Detailed Explanation:
Fresh milk from a healthy cow is naturally slightly acidic. This isn't due to lactic acid, but components like casein proteins, acid phosphates, citrates, and dissolved CO2.
The standard pH range for fresh cow's milk is 6.5-6.7. Buffalo milk's pH is slightly lower, around 6.7-6.8.
Evaluating the options:
(A) 6.1-6.3: Too acidic; suggests significant souring.
(B) 7.1-7.3: Alkaline; may indicate mastitis (udder infection).
(C) 6.0-6.1: Very acidic; milk would be sour.
(D) 6.6-6.8: Correctly includes the normal pH for both cow and buffalo milk.
Step 3: Conclusion:
Normal fresh milk has a slightly acidic pH range of 6.6-6.8.