Question

The optimum pH of coagulation of cow milk in the manufacture of paneer is

• A. 5.3
• B. 5.0
• C. 5.2
• D. 4.6

Hint:

To optimize paneer quality:
- Target pH = 5.3.
- Coagulation temperature = 70°C to 72°C.
This combination ensures a cohesive curd with optimal moisture retention and a soft, spongy texture.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Paneer is a traditional Indian heat-acid coagulated dairy product.
Its manufacture involves heating milk to 90°C and then adding an organic acid (such as citric acid) at 70°C to precipitate the casein and whey proteins into a cohesive curd.

Step 2: Detailed Explanation:
The pH at which coagulation is induced is a critical parameter that determines the yield, moisture retention, and texture of the paneer:
-Coagulation Mechanism:
At high temperatures, whey proteins denature and complex with casein.
Adding acid lowers the pH, neutralizing the negative charges on the protein molecules and causing them to precipitate.
-Optimum pH:
For cow milk, the optimum pH for acid-heat coagulation is \(5.3\) (or \(5.2\) to \(5.3\)).
- At this pH, the proteins form a soft, cohesive, non-sticky coagulum with optimal water retention, producing paneer with a desirable soft and spongy texture.
- If the pH is too low (e.g., near the isoelectric point of casein, pH 4.6):
The protein molecules lose too much water, resulting in a dry, crumbly, hard curd with poor cohesion.
- If the pH is too high (above 5.5):
Coagulation is incomplete, resulting in a cloudy whey, low yield, and a sticky, pasty curd.
Therefore, a pH of 5.3 is the standard target for optimum cow milk coagulation.

Step 3: Final Answer:
The optimum pH of coagulation of cow milk in the manufacture of paneer is 5.3, which corresponds to Option (A).