This is what happens when food touches your tongue

There are plenty of reasons to be thankful for each new day, but our sense of taste is definitely one of them. Thanks to our taste buds, each meal represents yet another opportunity to treat ourselves to a delicious culinary creation. Imagine if humans’ taste buds were dull and everything we ate tasted the same? It’s an unappetizing thought, to say the least.

Our sense of taste quite literally spices up our lives, but have you ever stopped to ponder exactly how that whole process works? Researchers from Ohio State University investigated what happens the moment different types of food touch our tongues, and came to several fascinating conclusions. The tongue, of course, is home to the vast majority of taste buds found in one’s mouth.

To start, they noted that taste buds recognize sweet flavors much faster than salty sensations. Why? Sweet tasting molecules are smaller and thus “diffuse” into our taste buds in a faster fashion. Additionally, it was also discovered that people typically recognize flavors faster if food or drink quickly moves over their tongue, as opposed to holding food in one’s mouth for a moment or two longer.

In total, the study’s authors believe they’ve compiled considerable evidence that both the speed with which food passes over the tongue and the size of food molecules, significantly influence our sense of taste.

“Our tongue has papillae on it that act like a sea of kelp in an ocean,” explains lead study author Kai Zhao, an associate professor of otolaryngology at The Ohio State University College of Medicine, in a release. “Those papillae – the small bumps that contain taste buds on the human tongue – move and sway as food or drink flow past them.”

The human tongue harbors four distinct kids of papillae; three contain taste buds and a fourth that serves as a source of oral friction.

During this project, the research team modeled all the various ways flavors (sweet, salty stimuli) can move around a tongue’s papillae. A computer model was also created capable of simulating earlier taste perception studies. All of those models were programmed to view the human tongue as a “porous structure,” meaning the spaces between each papillae essentially absorb flavors like holes on a sponge.

With this simulation in place, various eating scenarios were reconstructed. For instance, what would happen if a combination of both salty and sweet flavors passed over a tongue quickly? What if those flavors then passed over again at a slower rate?

They discovered that flavors passing over a tongue quickly tend to fall into the papillae gaps at a faster pace as well. This means those flavors would be registered and enjoyed more quickly than if the food had passed over the tongue slowly. Sweeter flavors, which feature smaller molecules, were also registered faster than salty flavors with larger molecular sizes.

“Smaller molecules may diffuse quicker, and we think this could be the reason they move through the papillae gaps more quickly,” Zhao says.

In comparison to the other senses, such as sight or sound, our sense of taste is a bit more delayed. While our eyes pick up on new sights and movements instantly, it takes our taste buds a bit longer to register and process flavors. These findings provide further insight into what happens during that short time, as well as the elements that can influence the process.

“That early response is changed depending on how the molecules of what we are consuming interact with the tongue’s surface,” Zhao adds. “It is a complex process.”

There you have it; there’s a responsive balance of molecules, papillae, and diffusion at play every time you take a bite of a sandwich. Moreover, the way food moves over our tongues can influence how tastes are perceived.

“Our taste buds are important,” Zhao concludes. “They help us figure out what food to eat, how much food to eat, and how to balance the body’s nutritional needs with its energy needs.”

The full study can be found here, published in PLOS Computational Biology.