discovered ways. TRP channels are another example of how when life
comes up with a structure possessing useful properties, it gets slightly
tweaked and modified this way and that and used over and over again
in many different locations in many different, though often related,
ways.
What we call flavor is a combination of several different channels of
sensory information. The mouth components of taste and pungency
are hugely important to the flavor of food and drink: salty, sour, sweet,
bitter, umami, cool, and several kinds of spicy hot—and a few more,
like the tingling of Sichuan pepper (genus Zanthoxylum) and the “fatty
taste” of fatty foods. Texture, how food “feels” in the mouth, also con-
tributes to flavor. And perhaps most important to flavor are aromatic
molecules, sensed via the olfactory system. As air from our mouth is
drawn back into the throat, it carries aromatic molecules from what-
ever we are eating or drinking up into our nasal passages from the
inside, the back way. In this manner, we are always smelling what we
are eating and drinking.
The aromatic qualities of food and drink are legion; thousands of
different molecules activating 350 different olfactory receptors in
thousands of different combinations, giving rise to a vast spectrum
of subtle olfactory perceptions of great nuance and complexity.
Spices, wines, and distilled liquors (such as gin, whiskey, brandy, ab-
sinthe, and many others), for example, are all defined largely by their
aromatic qualities. Flavor is infinitely interesting and immensely
enjoyable.
Everyone is familiar with what happens to the flavor of food and
drink when we have congestion as a result of a cold. Food is said to
“taste” flat and uninteresting. However, taste perception is actually
working just fine. If you pay careful attention, you will find that all the