How Taste Works

First let's get our terms straight. Scientifically, when we use the word "taste", we're talking about specific qualities conveyed to us via taste receptors on the tongue and in the mouth. These tastes include the classics: sweet, sour, salty and bitter. A new taste has been scientifically identified and verified. It's called umami (pronounced "oo-mommy"), and is elicited by glutamate, a common amino acid in food. This strict definition of taste is far different than what most people consider "taste" to be. For example, when we say, "This tastes good," what we're really talking about is not just taste itself, but a whole collection of sensory information, including taste, aroma and texture. Taken together, these qualities are more accurately termed "flavor."

Taste buds and more
If you've ever looked at your tongue and thought the little bumps on it were your taste buds you're not alone. You're also not correct! The little bumps on our tongues are actually called papillae. Inside some of these papillae are clumps of taste cells. These clumps of cells are actually the taste buds. On average, adults have about 7,500 taste buds.

When food comes in contact with the taste buds, signals are sent to the brain. Together with other sensory input, such as temperature or aroma, these signals are interpreted by the brain as flavor.

Sometimes our taste buds are "fooled." For example, certain signals are sent to the brain in response to the ingestion of sugar. However, when a sweetener such as aspartame is consumed, the same signal is sent—that of a sweet taste—even though aspartame contains no sugar.

Forget the tongue map!
Many of us remember learning about our taste buds in school, when we were presented with a "tongue map" showing which tastes buds were responsible for sensing which types of tastes. For example, the taste buds located on the back of the tongue were supposedly for bitter and salty, sour was sensed on the sides of the tongue and sweet was detected on the tip. Well, it's time to forget all about that because the famous "tongue map" was wrong! Scientists have known for years that the "tongue map" was based on misinterpreted research. (Textbook publishers seem to love the "tongue map" despite its inaccuracies, and still include it in numerous school texts.)

Although there are some differences in sensitivity across the tongue, it is not as defined as the "tongue map" indicates. In reality, all types of taste can be detected on all regions of the tongue, as long as the papillae contain taste buds.

top