: why does some spicies burn the mouth and some goes straight to your nose?


Some spicies like pepper burns the mouth and tongue. Some for example wasabi goes to your nose and if you eat enough the brain. What makes the difference?

In: Chemistry

Different chemicals that interact with different receptors in your cells. Those receptors trigger nerve impulses that your brain interprets as hot or spicy or pungent.

Chili peppers contain a chemical called capsaicin that interacts with the TRPV1 receptors in certain cells.

Wasabi contains a chemical called allyl isothiocyanate that interacts with a related, but different, receptor called TRPA1.

Both TRPV1 and TRPA1 receptors are in your mucus membranes –mouth, nose, eyes and … *ahem* … nether regions. (Pro tip: don’t take a piss after cutting habaneros; you’ll regret it.) But the allyl isothiocyanate molecule is larger and more volatile than capsaicin, so it’s less likely to get snagged by those TRPV1 receptors in your mouth; instead it floats up your nasal cavity and comes to rest in the nostrils or sinuses, giving you that nose-burning feeling, whereas capsaicin, the smaller molecule, gets captured more quickly by the cells in your mouth.

For the record, none of these chemicals “go to the brain.”