Question

why we close our eyes when we eat something sour ??

Answer 1

When foods dissolved in your saliva touch them, they tell the brain about the flavor of what you are eating. When they come in contact with very sour foods, your face might pucker up because the taste is strong and acidic. ... It may happen because we have an instinct not to eat things that are dangerous.

hope its helpful to you

Answer 2

Because they conduct signals to the brain indicating which taste group causes the stimulation. Foods from the three other taste groups cause the ion channels to narrow, but sour foods cause them to open wide. This is why the brain requires little stimulation to know the tongue is tasting something sour.