When you are chewing some food, you feel desperate for air and have to breathe through this mushy food. The tongue contains taste buds. What we call taste includes the smell of the food in our mouths. The epiglottis closes the entrance to the windpipe so that food does not go down the wrong way. For a couple of seconds just before we swallow our food, the trachea is blocked by the epiglottis, so we cannot breathe.
Food has to be slippery to make it easy to swallow.
This is why our saliva contains mucin which is a slimy protein. See how many dry biscuits you can eat in a minute. After a few, you cannot swallow any more because there is not enough saliva to make them slippery. The salivary gland produces saliva. This contains mucin and water to make the chewed up food slippery.