Why Are Some People In Love With The Bitterness Of Coffee?

According to SAEDNEWS, the bitter taste of coffee is the result of chemical reactions on the tongue, but the exact mechanism had remained a mystery. Now, scientists at the University of North Carolina have solved this long-standing puzzle using advanced imaging technology.

The Main Culprit

The secret of coffee’s bitterness lies in one of the taste receptors on our tongue called TAS2R43. Humans naturally have 26 bitter taste receptors, which evolved for survival to alert the body against swallowing toxic substances or harmful bacteria. Although scientists were aware of this receptor, until now they did not know exactly how coffee compounds activate it.

Scientists used “cryo-electron microscopy” to observe this process. This technology freezes molecules in a fraction of a second and produces 3D atomic-resolution images of them. Using this technique, researchers were able to observe the exact moment coffee compounds bind to this receptor.

Researchers used this tool to capture the interaction between the TAS2R43 receptor and two main bitter compounds in coffee: caffeine and a substance called mozambioside. This technique showed that coffee’s bitterness is not caused by caffeine alone. Microscopic images revealed that this receptor strongly interacts with another compound called mozambioside. This substance exists in coffee beans and its level changes depending on the roasting process, and it is up to ten times more bitter than caffeine.

This research also revealed another mystery: we do not all perceive coffee the same way. Human genetics vary, and about 20 percent of the world’s population does not have this bitter receptor active in their bodies. For these individuals, a cup of bitter coffee tastes much milder and more pleasant compared to others.

Beyond the Coffee Cup

The importance of this scientific discovery is not limited to baristas and coffee lovers. Understanding the molecular structure of this receptor provides an important roadmap for pharmaceutical scientists. With this technology, researchers may one day design essential but extremely bitter medicines in a way that they do not activate this tongue receptor. This could mark the end of bad-tasting syrups and pills for children and patients.