How and why do dried fruits beans swell when they are put in water?

Dried fruits and beans swell when they are put in water due to a process called imbibition. Imbibition is the absorption and retention of water by hydrophilic materials, such as cellulose and starch, which are the main components of plant cell walls. When dried fruits and beans are placed in water, the water molecules are absorbed by the hydrophilic materials, causing them to swell and soften.

The rate of imbibition depends on several factors, including the temperature of the water, the size and shape of the dried fruits or beans, and the concentration of hydrophilic materials in the plant cell walls. In general, imbibition occurs more quickly in warm water and with smaller, more irregularly shaped dried fruits or beans.

The process of imbibition is important for several reasons. First, it allows dried fruits and beans to rehydrate and become soft, making them more palatable and easier to digest. Second, imbibition helps to restore the nutritional value of dried fruits and beans, as the water-soluble nutrients that may have been lost during the drying process are reabsorbed. Third, imbibition can help to improve the texture and flavor of dried fruits and beans, making them more enjoyable to eat.

Here is a more detailed explanation of the process of imbibition:

1. When dried fruits or beans are placed in water, the water molecules are attracted to the hydrophilic materials in the plant cell walls.

2. The water molecules form hydrogen bonds with the hydroxyl groups (-OH) of the cellulose and starch molecules.

3. As more and more water molecules are absorbed, the plant cell walls begin to swell and soften.

4. The swelling of the plant cell walls causes the dried fruits or beans to increase in size and become softer.

5. The process of imbibition continues until the plant cell walls are fully hydrated and the dried fruits or beans reach their maximum size.

Imbibition is an important process that helps to rehydrate and soften dried fruits and beans, making them more palatable and nutritious.