How does salt prevent the growth of microbes in food?

Options

A. By killing microbes
B. By dehydrating food
C. By freezing microbes
D. By increasing food temperature

Answer

### Step-by-Step Solution:

1. **Understanding the Role of Salt**: Salt is commonly used as a preservative in food. Its primary function is to inhibit the growth of microbes, which can spoil food.

2. **Mechanism of Action**: When salt is added to food, it creates a high concentration of salt outside the microbial cells. This high concentration causes a decrease in the water concentration in the food.

3. **Process of Exosmosis**: The microbial cells (like bacteria) contain a higher concentration of water compared to the surrounding salty environment. Due to the process of exosmosis, water moves from inside the microbial cells to the outside environment (where the salt is).

4. **Dehydration of Microbes**: As water leaves the microbial cells, they become dehydrated. This excessive loss of water leads to the death of the microbial cells, as they require a certain amount of water to survive and function.

5. **Conclusion**: Thus, the primary way salt prevents the growth of microbes in food is by dehydrating them, leading to their death. Therefore, the correct answer to the question is that salt prevents the growth of microbes by killing them through dehydration.

### Final Answer:
Salt prevents the growth of microbes in food primarily by dehydrating them, which ultimately leads to their death.

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