What happens when the acidity of milk increases?

Options

A. It coagulates.
B. It becomes watery.
C. It becomes powdery.
D. It releases white fumes.

Answer

**Step-by-Step Solution:**

1. **Understanding Milk Composition**: Milk is naturally slightly acidic due to the presence of lactic acid, which is a weak acid.

2. **Effect of Increased Acidity**: When the acidity of milk increases (for example, by adding more acid), it affects the proteins present in the milk.

3. **Protein Structure Alteration**: The increase in acidity causes the milk proteins to lose their structure. This is because proteins are sensitive to changes in pH levels.

4. **Coagulation Process**: As the proteins lose their structure, they begin to coagulate. This means that the proteins clump together and separate from the liquid part of the milk.

5. **Loss of Colloidal Nature**: The coagulation process results in the loss of the colloidal nature of milk, which is the suspension of tiny particles in the liquid.

6. **Separation of Components**: During coagulation, the solid proteins separate from the liquid (whey), leading to the formation of curds.

7. **Nutritional Value**: The resulting coagulated milk is not suitable for direct consumption and has diminished nutritional value.

8. **Final Answer**: Therefore, when the acidity of milk increases, it coagulates. The correct answer is A. Coagulates.

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