Milk protein is curdled into calcium paracaseinate by -

Options

A. Maltose
B. Rennin
C. Trypsin
D. lactose

Answer

To answer the question "Milk protein is curdled into calcium paracaseinate by -", we need to analyze the options provided and understand the process involved in curdling milk.

### Step-by-Step Solution:

1. **Identify the Components**: The question refers to the curdling of milk protein, which primarily involves casein.

2. **Analyze the Options**:
- **Maltose**: This is a disaccharide sugar and not involved in protein curdling.
- **Renin**: This is an enzyme that plays a crucial role in the curdling of milk, especially in young mammals.
- **Trypsin**: This is a digestive enzyme that breaks down proteins but is not specifically responsible for curdling milk.
- **Lactose**: This is another sugar found in milk and does not contribute to the curdling process.

3. **Focus on Renin**: Renin, also known as rennin or chymosin, is secreted in the stomach of young mammals. It acts on casein, converting it into calcium paracaseinate when combined with hydrochloric acid (HCl) present in the stomach.

4. **Conclusion**: Since renin is the enzyme responsible for curdling milk proteins into calcium paracaseinate, the correct answer is **renin**.

### Final Answer:
Milk protein is curdled into calcium paracaseinate by **renin**.