Scientists suggest licorice as potential sixth taste candidate

Sweet, salty, bitter, sour, and umami are the five tastes we perceive. The sensations are picked up by taste buds distributed all over the tongue. Recently, scientists have discovered something interesting. We may perceive a sixth taste, which is best known to licorice candy enthusiasts.

Licorice candies spark such huge controversies that people either love them or deeply dislike them. They are extremely popular in Scandinavia, where you can buy them in every store. Although they look very appetizing, not everyone may like their taste. Licorice is initially salty and tart, then it even becomes... spicy. This is all thanks to ammonium chloride. This salt is responsible for the licorice flavour. And it is precisely this, according to scientists, that should join the basic tastes.

Initially, there were only four: sweet, sour, salty, and bitter. Then came umami, discovered by Kikunae Ikeda, a professor at the University of Tokyo. In 1908, he isolated glutamic acid from kombu seaweed. We can easily recognize this taste when eating Parmesan cheese, dishes with soy sauce, or fish sauce. Asians are masters at identifying the umami taste.

Europeans and North Americans had more difficulty with it, so the umami taste was only recognized in 2000. Scientists from the University of Miami discovered that receptors on the human tongue detect glutamic acid.

For many years, it has been known that we can detect the taste of ammonium chloride and respond to it. What if there are receptors on the tongue responsible for detecting it? This is the question Emily Liman from USC Dornsife College of Letters, Arts, and Sciences asked herself. The initial findings are quite positive. An article published in "Nature Communications" suggests that the first evidence has already been found.

The answer is the protein OTOP1, which detects sour taste. This protein is "located" in the cell membrane and forms an ion channel through which hydrogen ions enter the cell. Hydrogen ions are components of all acids, and when we taste sour foods, they reach the tongue thanks to the OTOP1 protein.