Sciencemadness Discussion Board - The taste of salts

The taste of salts

bquirky - 15-8-2009 at 01:22

I was day dreaming today and got to wondering what salts other than NaCl tasted like.

do salts with sodium taste more like table salt than chloride salts ? or will lots of things trigger the salt taste buds and all taste alike ?

Im not feeling inclined to go around sticking my finger in jars of random inorganic solutions but i cant seem to get the question out of my head.

12AX7 - 15-8-2009 at 01:38

Sodium and chloride salts tend to taste salty. Both together are quite salty. Something else, like sodium sulfate, is maybe half as salty. Simple explanation is probably that sulfate doesn't interact with the tongue (or much else, since sulfate isn't absorbed into the body, as I recall). Sodium bicarbonate is salty and tangy (as you might expect from the anion). Supposedly, nitrates have a cooling effect. Metabisulfites have a burning taste. Potassium is salty, but more bitter than sodium.

Acidic cations, ranging from alkaline earths to aluminum to transition metals, all taste sour and astringent due to their precipitation in neutral saliva. You can just imagine alum (potassium aluminum sulfate) depositing a sour, chalky layer of aluminum hydroxide all over your tongue... no surprise that's exactly how unpleasant it feels!

Tim

Jor - 15-8-2009 at 03:22

But lead acetate does not taste sour, while Pb(II) is an acidic cation! It tasts very sweet just like sugar!

And copper sulfate tastes very bitter.

I wonder how Hg(CN)2 tastes like

unionised - 15-8-2009 at 05:08

" Something else, like sodium sulfate, is maybe half as salty. Simple explanation is probably that sulfate doesn't interact with the tongue "
Sodium sulphate tastes bitter as well as salty.

I read that the only other thing that tastes of salt (apart from NaCl) is LiCl which isn't good news for the "low sodium food" industry.
The mixture of KCl and NaCl that's sold as a salt substitue tastes salty but with a bitter taste too.
I have heard that beryllium salts are sweet too. Oddly both Pb++ and Be++ are rather toxic but sweet; I wonder if it's a coincidence.

chloric1 - 15-8-2009 at 06:13

Sodium nitrate is pleasantly cooling with a mild aftertaste,
magnesium sulfate and calcium chloride are quite bitter. In fact I believe all calcium and magnesium salts are bitter. One exception is the magnesium citrate solution sold at the pharmacy. It is intolerably sour and when I use it as a laxative, I must dilute it twice its volume with gatorade.

User - 15-8-2009 at 07:07

Caliumchloride tastes very salty, it is used for people with certain diets those with low sodium etc.

chloric1 - 15-8-2009 at 12:24

Taste is actually a complex thing. I note that calcium chloride is salty but has bitter notes. Sodium chloride is simular without the acrid notes. Also, worthy of commenting, potassium chloride is sweetish in high dilutions. Many mineral water companies exploit this property to enhance there water as being more crisp and refreshing.

ammonium isocyanate - 15-8-2009 at 15:47

Beryllium salts are extreemly sweet, so much so that this quality was once used to identify them. Too bad that they're also very toxic.

12AX7 - 16-8-2009 at 01:15

I find that lead acetate is perhaps as sweet as sugar, but also sour / bitter and astringent, exactly as I'd expect. Those were white prismatic crystals, I don't think there was any appreciable impurity in them (whereas other lead acetate I've made ranges from green to reddish, due to copper and iron impurity).

Tim

bquirky - 16-8-2009 at 04:45

How do you judge if a salt is safe to taste ?

Just try a little and hope for the best ?

hissingnoise - 16-8-2009 at 05:42

IIRC, the Romans developed an unhealthy interest in lead acetate at one time so I'd be wary of tasting it.
NaClO3 tastes less salty than NaCl and there's a pleasant coolness to it.
NH4NO3 is very unpleasantly salty, though what I tasted was very impure.
I've found that all acids I've tasted have pretty much the same sourness. . .

chloric1 - 16-8-2009 at 08:17

Quote: Originally posted by hissingnoise

NH4NO3 is very unpleasantly salty, though what I tasted was very impure.

I would like to try pure ammonium nitrate on the grounds that sodium nitrate is such a pleasing taste.

Quote:

How do you judge if a salt is safe to taste ? Just try a little and hope for the best ?

Some salts are not worth tasting because of their toxicity. Salts of Lead, barium, cadmium, nickel or hexavalent chromium compounds. IIRC barium chloride can be lethal at 0.8 grams!

One small crystal might be enough for diarhea and heart spasms. Lead has the capability to find phosphate in the body and deposit in your bones accumulating! I don't even want to guess what cadmium does.

Formatik - 16-8-2009 at 12:26

The book Die organischen Geschmacksstoffe by Georg Cohn has about two pages mentioning inorganic compounds and salts, some examples are HMnO4, KMnO4 which taste sweetly bitter and astringent.

Sweetly (cooling) and alkaline is borax. Sweet to sweetly: sodium hexametaphosphate, zinc bromide, etc.

Sweetly tart (astringent): nickel salts, beryllium salts, samarium salts, potassium osmate, aluminium sulfate, alum, didymium sulfate.

Salty: LiF, NaF, NH4F (pungent), KBr (pungent), KI (spicy), disodium orthophosphate, ammonium bicarbonate, rubidium sulfate and perchlorate, etc. Salty and astringent: zinc chloride.

Bitter: phosphine, BaCl2, SrCl2, potassium sulfite, calcium nitrate (cooling), ammonium sulfate (spicy), potassium bromate, soluble magnesium salts, sodium tungstate, sodium vanadate, etc.

Don't particularily recommend munching on any of those, especially the heavy metal compounds.

I tried ammonium sulfate and didn't notice the bitterness much, all I can say is "it tastes like burning".

Reminds of the time I tasted vanillin only to find out that burns the tongue too.

[Edited on 16-8-2009 by Formatik]

entropy51 - 16-8-2009 at 15:04

Quote:

In the “good old days,” chemists routinely tasted newly synthesized compounds and
documented their taste as part of the scientific record. This practice may explain why
so many prominent chemists suffered poor health during that time. In the 19th
century, the German chemist Justus von Liebig once declared, “A chemist with good
health must not be a good chemist”

We have a number of very good chemists here!

sergide - 16-8-2009 at 16:06

Nobody here has tried pure ammonium nitrate? It's interesting, it's a very sour salty which kind of burns. But not unpleasant in small amounts.

hissingnoise - 17-8-2009 at 07:59

And you half-expect it to taste like snow (the white variety)?

sergide - 17-8-2009 at 12:59

Oh yeah that's another thing... it burns but it feels kind of cold, obviously it's used in snowpacks.

blogfast25 - 19-8-2009 at 07:47

I'm a bit surprised no one has brought up ammonium chloride: aka salty liquorice

http://en.wikipedia.org/wiki/Salty_liquorice

Some of these candies are actually covered in the stuff, yum yum!

Everado E. Dinavo - 19-8-2009 at 14:13

Quote: Originally posted by chloric1

...I don't even want to guess what cadmium does.

Cadmium gives you uncontrollable tremors and other really bad things.

I've read that in even relatively low concentrations (1ish% w/v), cyanide salts burn the mouth and esophagus on contact.

chloric1 - 19-8-2009 at 17:28

sodium metabisulfite taste a little smokey and saline. It reminds me of forth of July with a salty twist. I am sure Sulfur dioxide is liberated on contact with the moist tongue giving the characteristic acrid smoke taste to metabisulfite.

not_important - 21-8-2009 at 08:51

The 'saltiness' of an ion seems to be related to it's ionic radius and hydration sphere. Most metal salts can invoke sweetness, saltiness, bitterness, and sourness, depending on their concentration. Sodium only presents sweetness and saltiness, lithium adds sourness that sometimes is confused with bitterness. Some can also cause a metallic taste, alkaline salts seem to do this more.

As the ionic radius moves away from that of sodium, the perceived bitterness generally increases. In the alkali metals the series goes Li>Na>K>Rb>Cs. Ammonium is an exception, it is saltier than sodium even though its radius is close to Rb; ammonium's taste is complicated by the acidic nature of its salts, which adds a sour or sharp element to the taste. Lithium salts tend to be slightly alkaline and often have a sour overtone as the concentration increases.

Ca(2+) is saltier than Na(1+), having nearly the same ionic radius 0.99 vs 1.02 Å, but becomes bitter as the concentration increases. The alkaline earth series is Mg < Ca > Sr > Ba with the ends of the series being bitter over salty.

The halides become less salty and more bitter as the ionic radius increases. This is less pronounced than with the cations, KI is distinctly bitter while NaI is less so, NaBr is mostly salty while KBr is mixed salty-bitter.

Oxi anions seem give a cooling sensation to a greater or lesser degree, NO3>ClO3>ClO4>SO4. Weaker acids, CO3(2-) and SO3(2-), can give sour or bitter sensations as well, likely as their solutions are generally slightly alkaline.

A small amount of acidic nature is perceived more as 'sharpness' rather than 'sour'. Sharp or slightly bitter tastes combined with distinct saltiness are often described as 'spicy'.

Be does taste very sweet in low concentrations, apparently it is sweeter than sucrose, going bitter as the concentration increases. Lead compounds taste sweet as well, in both cases this is attributed to the size of the ion and hydration sphere. Some of the other metals' salts taste sweet at low concentrations but rapidly turn bitter as the concentration is increased.

chloric1 - 21-8-2009 at 16:30

Sounds reasonable not-important. An especially horrid taste is a mix of potassium and magnesium sulfates. The double salt does form pretty crystals.

bquirky - 22-8-2009 at 04:27

are any non hevey metal sulfates particularly toxic in tastable quantitys ?

chloric1 - 22-8-2009 at 17:00

Not even sure if sulfates or sulfuric has any role in body chemistry of humans but AFAIK the sulfate ion itself is not appreciably toxic. Although sulfuric acid mists are stated to be carcingenic on prolonged exposure. But in my opion, the pulmonary problems and possible COPD would be more worrisom for me than some vague cancer possibility. The only sulfates that in my opinion are worth tasting are sodium sulfate and ammonium sulfate. Sodium sulfate is so cooling and mild while ammonium sulfate is very salty without making you cringe. I might try lithium sulfate but it might taste like magnesium sulfate(YUK!

Everado E. Dinavo - 22-8-2009 at 18:23

Sulfate ion itself is non-toxic but it has laxative effects in appreciable doses. Depending on the salt, the cation might be toxic, but most of the heavy metal sulfates are insoluble. I'm not sure what the effects of lithium ions on the body are, so I would be hesitant to try Li2SO4 at all.

12AX7 - 22-8-2009 at 18:44

It's my understanding that sulfate is not absorbed by the intestine. Hence, fairly large doses of sulfates, like magnesium sulfate, have an osmotic bulking effect and therefore act as laxatives.

Tim

IrC - 22-8-2009 at 21:32

The one I have wondered about in the past is who was the taste tester who said prussic acid tasted like bitter almonds and did he actually have enough time left to relate this taste to anyone else?

kclo4 - 22-8-2009 at 22:22

Perhaps he is the one who also define the taste of the nitrite salts

I'd think one could get a small enough amount to be safe, especially if they had the antidote right next to them - though probably back then... They probably didn't have the antidote.

zed - 31-8-2009 at 19:22

Potassium Chloride tastes pretty much like Sodium Chloride.

Very handy. Because, unlike regular salt, consuming Potassium Chloride does not cause excessive fluid retention. In your diet, substituting KCl for NaCl, will trim your weight a few pounds, AND lower your blood pressure somewhat.

NuSalt, a Potassium Chloride product, costs about $1.50 per 3 Ounces, at your local WinCo.

Klute - 1-9-2009 at 07:40

I actually tasted sodium nitrite but without putting it in my mouth!

When I had that H2S exposure accident, I injected a fair amount of NaNO2, and after the initial burn in the arm, had a salty/bitter taste in the mouth.. This happens quite often during IV injections of products, I have been told this happens with good quality meth: you get the slight taste after an IV..

sparkgap - 1-9-2009 at 18:41

"Potassium Chloride tastes pretty much like Sodium Chloride."

You think? I can differentiate KCl and NaCl blindfolded. KCl has a bitter aftertaste that lingers for me... blech.

sparky (^_^)

psychokinetic - 1-9-2009 at 22:53

I suppose it depends on the individual too......not getting too metaphysical about it all

not_important - 1-9-2009 at 23:09

Quote: Originally posted by sparkgap

"Potassium Chloride tastes pretty much like Sodium Chloride."

You think? I can differentiate KCl and NaCl blindfolded. KCl has a bitter aftertaste that lingers for me... blech.

Everything I've read backs you up. As you taste increasing concentrations of KCl, it goes from vaguely sweet to salty to bitter+salt, with the bitter flavour lingering. Placing solid KCl on your tongue pushes the concentration up into the levels that evoke bitterness, using it to salt soup may not reach those concentrations.

And, yes, there is genetic variation on the sensitivity to the salt and bitter tastes.

chloric1 - 2-9-2009 at 02:31

Nobody mentioned alkaline substances. So I will.

Ammonium hydroxide in less than 5% taste much like baking soda.

Sodium Carbonates starts off like the bicarbonate but ends with a shocking strong bite. I think this is the threshold of alkalinaty tasting as everything more basic is just going to taste outright caustic ie sodium metasilicate, trisodium phosphate etc etc. Incidently, I use TSP to soften cooked and baked on food residues on my frying pans.