Why does a sweet taste appear in the mouth after bread, if you hold it in your mouth for a while?

In the mouth, there is not only chewing and mixing of food. Saliva has some enzymes that start the process of breaking down carbohydrates. There are quite a lot of them in bread. When saliva wets the bread, it breaks down into polysaccharides. They also give a sweet taste. This process is not able to completely break down carbohydrates. Digestion continues in the stomach and intestines. The ptyalin enzyme breaks down starch in the mouth. In addition to digestive enzymes, saliva has antiseptics and viscous substances.