You just ordered a pizza. As soon as you hit that ‘submit button’ order you’re already wondering where the hell your pie is and that if it takes longer than the time they said it would you’re going to think about calling the restaurant, but then you remember you’re a nice person/don’t want to risk them messing with your food.
You get the knock on your door. Your pizza is finally here. You end up tipping the person an extra few bucks despite the fact you just waited far too long for a pizza that just sat in a box for a half-hour, because again, you just have that good of a heart.
You put the box on the table, you open it, you disregard the amount of excess oil in the middle of the pie and immediately your mouth starts to water.
This isn’t your first pizza and you definitely ate half a box of Goldfish and a scoop of peanut butter while you waited for your pizza to arrive so you’re not actually all that hungry. So, what gives? Why is your mouth watering?
Even though we never really think about why our mouths are watering while we’re trying to shovel food down our gullets, there’s some pretty simple and common-sense science behind it.
Saliva simply lubricates the food we put in our mouth’s, it helps us chew food, and also contains enzymes that help begin digestion before we even swallow.
There are two types of saliva, actually: mucous and serous. Mucous saliva should be pretty self-explanatory, it’s thick and full of mucus. Serous saliva is what fills in your mouth when you first lock eyes on the food you’re about to inhale. Serous saliva can even show itself when you’re simply thinking of a certain food.
[H/T Mental Floss]