Scientists suggest liquorice could be the sixth basic taste

Sweet, salty, bitter, sour, and umami are the five tastes we perceive. Taste buds distributed all over the tongue pick up these sensations. Recently, scientists have discovered something interesting: we may perceive a sixth taste, which is well-known to enthusiasts of liquorice sweets.

Liquorice sweets spark such significant controversies that people either love or intensely dislike them. They are prevalent in Scandinavia, where you can buy them everywhere. Although they look very appetising, not everyone may be fond of their taste. Liquorice is initially salty and tart, then it even becomes... spicy. This is all thanks to ammonium chloride. This salt is responsible for the liquorice flavour, and it is precisely this that scientists believe 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 recognise this taste when eating Parmesan cheese, dishes with soy sauce, or fish sauce. Asians are masters at recognising the umami taste.

Europeans and Americans had more difficulty with it, so umami taste was only recognised 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.