12 January - 20 June 2016

Aversion to very high concentrations of salt

20 Feb 13

Findings by Charles Zuker, PhD and colleagues at Columbia University Medical centre show how mammals are repulsed by high salt concentrations.  Published in Nature online, this study finally uncovers the mystery of the salty taste receptors.  Mammals have receptor cells on the tongue which are able to detect five basic tastes: sweet, umami (a savoury or meaty flavour), bitter, sour and sodium salt.  The sweet and umami responses are attractive and the bitter and sour are aversive.  The salty taste is unique in that at low concentrations it is pleasant yet dangerously high concentrations are powerfully repulsive.  Scientists are aware of the detection of low concentration sodium on the tongue.  The taste receptor cells expressing the epithelial sodium channel, ENaC, highly selectively detect the ion prompting taste perception in the brain.  The cellular, non-selective response to aversive concentrations of salt however was unknown.  Zuker et al were able to use allyl isothiocyanate (AITC), found in mustard oil, to suppress the response to high salt concentrations yet without affecting responses to low, healthy concentrations.  Interestingly they discovered that the bitter response was also suppressed and no other stimuli were affected.   The research team proposed that it was the bitter response that was targeted by AITC, the first insight into the high-salt sensing pathway. They were able to confirm this proposition using mice that were genetically engineered to lack the bitter stimuli.  The mice were deprived of water for 24 hours and then offered attractive assays or aversion assays.  The repulsion of dangerous levels of salt was certainly lessened but not to a full extent.  It was then reasoned that the missing part to the high-salt pathway was the sour receptors, the only other taste which repulses.  Double mutant mice which genetically lacked both receptors for bitter and sour tastes were able to drink water with concentrations as high as sea water and still be attracted to it.  It was therefore reported that ’the 'co-opting' of sour and bitter neutral pathways evolved as a means to ensure that high levels of salt reliably trigger robust behavioural rejection.'   One of the researchers, Dr Oka, mentioned the possibilities of using this research to 'make low concentrations of salt taste saltier.'  It may also be possible to make the taste of potassium chloride more pleasant, the health effects of which are less severe.

RSSL's Product and Ingredient Innovation Team, has considerable experience in re-formulating products to provide more healthy options including low salt, low sugar versions and using pre- and probiotics.  Using RSSL can help speed up your development cycle considerably.  For more information please contact Customer Services on Freephone 0800 243482 or email enquiries@rssl.com

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry