Why does cooking dried pasta in a pot of boiling water make the swell and get softer?

Cooking dried pasta in a pot of boiling water causes it to swell and get softer due to the process of hydration and starch gelatinization. Here's a detailed explanation of what happens during the cooking process:

1. Hydration: When dried pasta is added to boiling water, it begins to absorb water. This process is known as hydration. The water molecules penetrate the pasta's structure and cause it to swell and expand. As a result, the pasta increases in size and becomes more pliable.

2. Starch Gelatinization: Pasta is made from durum wheat flour, which is rich in starch. Starch is a type of carbohydrate that consists of two components: amylose and amylopectin. When the pasta is cooked in water, the heat causes the starch granules in the pasta to absorb water and swell. This process is known as starch gelatinization. As the starch granules swell, they break down and release glucose molecules. These glucose molecules dissolve in the cooking water, creating a slightly viscous liquid.

3. Protein Coagulation: In addition to starch, pasta also contains proteins, primarily gluten. When the pasta is cooked in water, the heat causes the gluten proteins to denature and coagulate. This process helps to bind the pasta strands together and give it a chewy texture.

4. Softening: The combination of hydration, starch gelatinization, and protein coagulation results in the softening of the pasta. The water molecules absorbed during hydration help to break down the pasta's rigid structure, while the gelatinized starch and coagulated proteins provide a soft and chewy texture.

It's important to cook pasta according to the recommended cooking time provided on the package to ensure that it reaches the desired level of doneness. Overcooking can result in mushy pasta, while undercooking can leave it hard and chewy.