Question

Question: In the supermarket, lettuce and other products are often sprayed with water. Explain why this makes vegetables crisp.

Short answer

Water absorbed by plant cells allows them to remain turgid. Therefore, to keep the vegetables crispy, water is sprayed on lettuce and other similar products.

Step-by-step solution

Movement of molecules

All molecules possess some kinetic energy which allows them to diffuse in the surroundings. The diffusion rate will be faster, given that the concentration gradient is faster. On the other hand, osmosis results in the movement of water from high pressure to the area of low pressure.

Hypotonic solution

A hypotonic solution is that which possesses lesser particles when compared to other solutions. These solutions are generally used to dehydrate hospitalized patients.

Explanation for water spray on lettuce leaves

Water contains fewer molecules dissolved in it when compared to plant cells. Due to this, water is absorbed by the plant cells. This results in turgidity of cells of vegetables instead of plasmolysis of cells.

In plasmolysis, the plasma membrane is detached from the wall, and plant cells shrink. The turgidity allows to retain the crispiness of vegetables like spinach and lettuce, and their wilting does not occur.