Taste and Sensation (To be continued….)

Most people are pretty comfortable with our sense of taste - we've got taste buds that let us experience the salty, bitter, sweet, sour and umami characteristics of food. And that's pretty much it, right? That's how we taste our food, end of story.

Eh, not so much as it turns out. There are whole lot of other factors that play into how we experience what we eat. The most important thing is likely taking into account that our sense of smell contributes significantly to how we experience flavor. But that's just scraping the surface.

Have you ever wondered about the cool freshness from a piece of mint gum? How about the spiciness of a jar of salsa? Those aren't quite smells or tastes, are they? There's actually a whole area behind the mouth that's full of nerves that communicate sensations like tingling, warmth, and even pain to brain.

Ever burned your tongue? There are areas all over your mouth, esophagus, and even larynx that lack taste buds but have these sensing fibers that send that "ouch I burned my tongue on something hot" message despite the fact that this feeling has nothing to do with taste.

The nerves responsible for these additional sensations that have nothing to do with taste or smell are called the Trigeminal Nerve System. This is the largest cranial nerve is the primary nerve responsible for taste and sensation in the face and the motor nerve for chewing. Pain, mouthfeel, temperature, tingling, prickling, and multiple sensations at once (polymodal) are all results of receptors in this nerve system. 

These nerves affect the face and head in three zones, shown in the picture below. Clearly, these sensations expand far beyond the tongue. 

Three Trigeminal Areas
(Wikimedia Commons)

In the next post, I'll go into detail on the compounds that are used to create these non-flavors. 

Ashley

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1 Rowe, David J (ed.) (2005) Chemistry and Technology of Flavors and Fragrances. Blackwell Publishing: Poole. Ch.9 pp199-205.