See gum naturally looses its flavor. It's not the scientists faults. Gum isn't ment to be swallowed. Plus our bodies can't even digest gum. To make chewing gum chewy you add the main ingredient which is gum base. Adding softeners is what keeps the gum from going hard and dry. A very long time ago chewing gum was made from different kinds of tree saps. Chewing gums flavors can come from different places. Some of the most popular flavors for gum are menthol, frut, spearment, and of course pepperment. Now to the part where you learn why these flavors don't last. The flavors don't last because the spit in your mouth digest the sweeteners and the flavoring. Gum base can not be broken down like the other ingredients.
Flavor: I think flavor is something you add to food or other edible things to make it taste good.
Ingredient: I think a ingredient is something you add in a mix to make the dish complete.
Saliva: I think saliva means spit from your mouth.