Question

Why does a bread piece taste sweeter, when you chew it?

Answer 1

The sweetness in food occurs due to the presence of sugar in it or in other words called saccharides as the digestion of sugars takes place in the mouth with the help of the salivary glands. These sugars also called amylase are found in the saliva as well.

Complete answer:
When the polysaccharides break into disaccharides in the mouth after the process of digestion then the bread tastes sweeter. Although bread is not made up of any type of saccharide, but, when we chew it for a longer time than due to the presence of the salivary glands in the mouth, it will help in the breakdown of sugars. This digestion of sugars occurs with the help of the salivary amylase enzyme. This salivary amylase results in the formation of sugar called maltose which tastes sweeter and is present in the mouth where its digestion occurs.
The food enters through an interior canal-like opening called the alimentary canal located in the mouth region. When the food enters it is mixed with the help of teeth as it chews and is then swallowed through the tongue. The salivary glands secrete saliva in the mouth in which salivary amylase enzyme is found. This enzyme helps in the breakdown of complex sugars into simple ones like starch into maltose.
The polysaccharides break down into disaccharides or maltose takes place in the mouth region with the help of an enzyme called salivary amylase. The activity of the amylase enzyme is then stopped by the stomach where further digestion of the carbohydrates takes place.

Note:
The digestion of proteins takes place in the stomach where enzyme pepsin is involved in the breakdown of the proteins into peptide molecules. The digestive system consists of two major parts called the alimentary canal and the digestive glands. Both these parts of the digestive system are of great significance. The digestive glands secret various juices that help in the digestion of various food materials in the alimentary canal.