The basic known flavors are sweet, salty, sour, bitter and umami. Now maybe we can add one more, which is… SAL AMMONIC!
In the Netherlands we like it: sal ammoniac. We often use it in licorice, which gives this dessert a distinctive salty taste. Researchers have now discovered that physiological receptors in human taste buds are particularly responsive to ammonia. This means that sal ammoniac can probably be classified as the sixth basic taste.
Five basic flavours
The standard list of basic flavors now consists of five flavors, namely salty, sweet, sour, bitter, and umami. Umami is the latest addition to this list. Japanese scientist Kikunae Ikeda first introduced the concept of “umami” as a basic taste in the early 1900s. It eventually took about eighty years before the scientific community officially recognized that umami should be considered a primary taste.
Ammonium chloride
This means it may be a while before sal ammoniac is added to this list. But there is no doubt that it has a chance of success, according to the researchers. In a new study published in the journal Nature CommunicationsNeuroscientist Emily Lehman and her team discovered that the tongue responds to ammonium chloride. This happens by activating the same protein receptor responsible for detecting sour taste. “If you live in a Scandinavian country, you probably know and love this flavour,” Lehmann says. This certainly also applies to Dutch people. Ammonium chloride is also known as ammonium sal. In many northern European countries, salty licorice has been a popular dessert since at least the early twentieth century.
Tong
Scientists have known for many years that the tongue reacts strongly to ammonium chloride. They weren’t sure which specific receptors were responsible. But now Lehman and her team have changed that. Recently, they were able to identify a protein called OTOP1 that is responsible for detecting sour taste. They suspected that this protein might also respond to ammonium chloride because of the way it affects acidity in cells.
an experience
To test this, the researchers inserted the Otop1 gene into human cells grown in the laboratory. They then exposed them to both acid and ammonium chloride. “We found that ammonium chloride activates the OTOP1 receptor very strongly,” Lehman says. “It activates as well as or better than acids.” In addition, further experiments on mice confirmed that animals with the OTOP1 gene avoided ammonium chloride, while mice without this gene had no problems with its taste.
Toxic
Lehman hypothesizes that the ability to taste ammonium chloride may have evolved as a protective mechanism to help organisms recognize and avoid harmful substances. “Ammonium is somewhat toxic,” she explains. “So it makes sense that our sense of taste evolved to be able to detect them.” Furthermore, the team found that sensitivity to ammonium chloride can vary between different species, possibly due to different habitats. For example, the OTOP1 protein in chicken is more sensitive to ammonium than the zebrafish protein. This may have something to do with the fact that fish simply don’t encounter this substance much in the water, while chickens in their coops have to deal with ammonium, which they must avoid to stay healthy.
Six basic flavours
Overall, researchers suggest that ammonium chloride can be considered the sixth primary taste. But this is far from official. In general, the process of creating a new basic bait is a complex and lengthy task that requires careful scientific research. Creating a new base flavor is not an everyday occurrence, and is usually done after extensive research and discussion in the scientific community.
In future research, the researchers plan to gain more knowledge about how the OTOP1 receptor responds to ammonium chloride. In this way they hope to discover more about its evolutionary significance. And who knows, maybe sal ammoniac will eventually be officially recognized as the sixth essential taste – perhaps only within eighty years.
