Sweet , savory , sour , acrid , and umami are the five classic tastes our tongue are trained to detect . But lurking on the border of this flavorful lineup is a lesser - known sense : ammonium chloride . Best know as the tongue - tingle punch behind salty licorice , this sharp taste might just deserve a spot among the basic five .
discernment is a character of chemical perception picked up by special sense organ in the backtalk . Each of the five basic preference is recognise by its own specific sense organ or circle of receptors . Scientists have known for decade that thetongueresponds to ammonium chloride , but research from USC Dornsife managed to nail the receptor on the tongue that react to it .
Reporting their finding in the journalNature Communicationsin 2023 , the team explain that it ’s all thanks to a protein , called OTOP1 , that ’s found within cubicle membrane and form a epithelial duct for hydrogen ion run into the cell .
To confirm their hypothesis , the squad produce research laboratory - grown human cells that have the OTOP1 protein and then exposed them to acid and ammonium chloride . They found that ammonium ion chloride activate the OTOP1 receptor just as effectively as acid . Further experiments showed the protein work likewise in humans , chickens , and even zebrafish , though how sore it is changes bet on the species .
Ammonium chloride is an aversivetastethat most likely evolved to help avoid harmful substance , since ammonia is noxious to humankind and other animals . However , it is evident that humans can learn to enjoy it , just like how we ’ve acquired a penchant forspicyor acidulent food . Ammonium chloride savour is prominent in salt licorice confect , a particularly democratic confect in Nordic countries , the Netherlands , and northern Germany .
“ If you live in a Scandinavian country , you will be familiar with and may like this taste , ” Emily Liman , a professor of biologic sciences at USC Dornsife and study writer , order in astatement .
“ Ammonium is somewhat toxic , ” she added , “ so it make sensory faculty we acquire gustatory sensation mechanism to detect it . ”
OTOP1 is thesame receptorthat pick up on acidity , which we taste as a sour flavor like Citrus limon succus or vinegar . However , it does n’t appear to be but an extension of acid - perception , as it just uses the same hardware and bank on a unlike mechanism .
The idea of adding “ young ” sentiency to our palate of basic tastes is n’t whole fresh . In 1908 , Nipponese chemistKikunae Ikedaidentified the chemical basis of a discernment he named umami , the meaty or brothy flavor found in food like soy sauce , seaweed , anchovies , miso , Pisces sauce , Worcestershire sauce , and Marmite . The Son can be slackly translated from Japanese as " pleasant savory taste , ” although there ’s no English word that truly captures its burden .
That said , ammonium ion chloride has contender for its place as the “ 6th ” basic taste . Prior to this study , many scientist havetried to make the casethat “ oleogustus ” – Latin for “ a taste for fat ” – should be treated as its distinct basic taste .
Do n’t confuse it with the delicious sense of taste of fat we perceive when we eat thing like creamy cheese or a juicy steak . Just like bitter and ammonium ion chloride , oleogustus is mean to act as a deterrent . It ’s the preference of oxidized oil that ’s meant to signal to our mind , “ hold back eat that . ” You ’ll scantily notice it in small concentrations , but a large dose will certainly put you off your fatty snack .
Anearlier version of this articlewas bring out in October 2023 .
