Most coffee contains between 1 and 1.5% caffeine, the chemical compound responsible for keeping us awake.
This might seem obvious, but caffeine is very bitter. Some have described caffeine as tasting “alkaline,” “slightly soapy,” and “sharp and acerbic,” even in small doses. So why aren’t people squirming as they sip their morning cup of coffee? A team of German researchers wanted to find out.
“The significance of this work lies in explaining why coffee beverages do not taste of caffeine, even though the caffeine concentration of coffee is far above the perceivable level,” said co-author Michael Gigl in a press release.
The answer, the researchers found, lies with a group of compounds called melanoidins. Melanoidins are produced during roasting, and the researchers isolated them to examine how they interact with caffeine.
In the study, published in the Journal of Agricultural and Food Chemistry, a group of panelists tasted samples. They rated those with melanoidins and caffeine as approximately half as bitter as those with caffeine alone. In fact, the taste of caffeine became noticeable only when the researchers added significantly more caffeine to the melanoidin-containing sample than would be found in a regular coffee.
The researchers theorize that melanoidins may bind to caffeine to “physically obstruct access” to our tongue’s bitter taste receptors. The interactions between melanoidins and caffeine “have a significant influence on the perceived bitterness of caffeine and, consequently, of coffee,” they concluded.
Researchers hope their findings will spur further research, such as exploring how the addition of melanoidins could improve the flavor of instant coffee and other coffee products.
Read more on caffeine’s bitter barrier compound here.
Photo by Robert Shunev on Unsplash
