Why food makes our mouths water

Over an entire day, the average person produces one to 1.5 litres of saliva

There is a a logical reason why food makes us salivate.

Our brains subconsciously react to the smell, sight and even thought of food with the increased secretion of saliva.

This is because we need saliva to help teeth chew and prepare food to be digested, as this video by the American Chemical Society (ACS) explains.

Saliva is 99.5 per cent water and 0.5 percent proteins, electrolytes and lipids (a group of natural occuring molecules).

Amylase, a protein enzyme found in saliva, begins the process of breaking down food before it enters the stomach and intestines.

ACS Chemistry 2015 Champion Hadi Fares said: "The nerves that control saliva production are part of a reflex system.

"They fire without you consciously thinking about it when you are eating. The smells, tastes and even the movement of your jaw muscles can activate this reflex."

The part of the brain responsible for this salivary reflex is the medulla oblongata which controls a variety of functions from sneezing to vomiting.

On recieving these stimuli, the medulla oblongata sends neurotransmitters to the glands to produce the saliva.

In addition to its digestive role, saliva is essential to keeping the mouth and teeth healthy and hygenic.