How is food texture altered during digestion?

Food texture is altered during digestion through mechanical and chemical processes that break down the food into smaller particles.

Digestion begins in the mouth where the mechanical process of chewing breaks down food into smaller pieces. This not only alters the texture of the food but also increases the surface area for enzymes to act upon. The food is then mixed with saliva, which contains the enzyme amylase. Amylase begins the chemical digestion of carbohydrates, further altering the texture of the food by breaking down complex carbohydrates into simpler sugars.

The food then travels down the oesophagus and into the stomach through the process of peristalsis. In the stomach, the food is mixed with gastric juices containing hydrochloric acid and the enzyme pepsin. The acid denatures proteins in the food, unravelling them and making them more accessible to enzymatic action. Pepsin then begins the process of breaking down proteins into smaller peptides. This combination of mechanical churning and chemical digestion in the stomach significantly alters the texture of the food, turning it into a semi-liquid substance called chyme.

The chyme then enters the small intestine where it is mixed with bile from the liver and pancreatic juices from the pancreas. Bile emulsifies fats, breaking them down into smaller droplets that can be more easily digested by lipase, an enzyme in the pancreatic juice. This process further alters the texture of the food, breaking down fats into fatty acids and glycerol. The pancreatic juice also contains enzymes that continue the digestion of proteins and carbohydrates.

In summary, the texture of food is significantly altered during digestion through a combination of mechanical processes such as chewing and churning, and chemical processes involving various enzymes and other digestive juices. These processes break down the food into smaller and smaller particles, changing its texture from a solid or semi-solid state to a liquid state.