Coke (soda) Bubbles and pain?

[YT2095]

does anyone know why fizzy drinks such as Coke causes mild pain of the tongue?

at 1`st I thought it was maybe the Phosphoric acid and all the goodies in it that were creating this effect, then I carbonated plain tap water and it did the same?

it`s works especialy well if you keep the liquid in your mouth for a while, now is it the carbonic acid? well I wondered that also and so I made some, it wasn`t that either!

that leaves me thinking it`s something to do with the bubbles, maybe the tiny bursting like little explosions on the tongue causing trauma to the delicate tissues? or maybe the evolution of the gas from the liquid that maybe in between the buds of your tongue at the time and suddenly displace them?

 

any ideas?

[aommaster]

well, if you said 'carbonated plain tap water', then it must be a reaction within the carbonic acid "if i am not mistaken' and the taste buds. Maybe they think its that chemical in chillis (forgot what it is called again!)

[YT2095]

I tried carbonic acid, it did nothing at all. Thats what leads me to beleive it has something to do with the Fizz or bubbles

[Radical Edward]

have you tried a different gas? Your initial assumption is probably right. There could also be some localised energy fluctuations as the molecules bubble and locally freeze bits of your tongue.

[YT2095]

nope, never tried a different gas, other than Nitrogen or maybe Oxygen or inert gasses, I don`t think I`de trust any others to consume, and I don`t have any of those at the moment either, otherwise I`de be kicking a$$ on the Lightbulb challenge

[admiral_ju00]

it`s something to do with the bubbles, maybe the tiny bursting like little explosions on the tongue causing trauma to the delicate tissues?

that was what i always assumed.

i'm eager for your completion with the experiments, and the shared findings.

[Radical Edward]

my guess then would be to take three cans of coke, open one and drink it and then fill the can with water (as a control) open another and let it go flat. now put all three in a room for a while to let them reach thermal equilibrium with the environment. now open the final can of coke, and stick a thermometer in all three and look for changes in temperature (it would be nice to have a control unopened can of coke. I suppose you could do this by having each in a water bath and measuring the temperature of that)

 

this is a bit redundant though, since we know that when pressure is released like that, the temperature drops enough to freeze things - basic thermodynamics. Also I have seen it, when we used these little canisters of pressurised CO2 as a propulsion device - lots of water froze around the canister. The trick is identifying whether it is anything else, and I don't see anything else it could be apart from local freezing, judging from the experiments you have done so far.

[Radical Edward]

that was what i always assumed.

i'm eager for your completion with the experiments' date=' and the shared findings. [/quote']

 

I don't think it is bursting of the bubbles, since the bubbles aren't bursting, they are just forming as the pressure is released.

[admiral_ju00]

I don't think it is bursting of the bubbles, since the bubbles aren't bursting, they are just forming as the pressure is released.

 

a bubble does burst when it hits various surface structures, does it not? there are some exceptions, but most things that will touch the bubble(or vise-versa) will cause the bubble to burst

[Glider]

I'm just guessing but: Flat coke doesn't have the same effect so it has to do with the fizzing. This leaves two possibilities. It could either be chemical; carbonic acid coming out of solution, or it could be mechanical; intense stimulation of receptors by the bubbles.

 

If you look at a glass of coke (or lager or any fizzy drink), you'll notice that bubbles need a 'seed' on which to form, i.e. some impurity or imperfection in the surface of the glass and you'll see a constant stream of bubbles from those places. If you drop a pinch of salt into coke (i.e. introduce a whole bunch of 'seeds') you see the fizzing suddenly becomes quite violent as carbonic acid rapidly comes out of solution around each grain. If you pour coke into your mouth, the same thing happens. The 'seeds' in this case though will be nerve endings (taste buds and so-on) and it is around these that carbonic acid comes rapidly out of solution into carbon dioxide. Most receptors are sensitive to pH and many respond to levels of carbon dioxide. I would expect these to be intensly stimulated and to be firing high frequency volleys to the CNS. It might even be that the stimulation is of sufficient intensity to trigger some polymodal receptors (C and A-Delta fibres) that are associated with nociception.

[Radical Edward]

a bubble does burst when it hits various surface structures, does it not? there are some exceptions, but most things that will touch the bubble(or vise-versa) will cause the bubble to burst

 

do bubbles burst underwater though? As I said, my money goes on local temperature variations.

[felinlasv]

I think it's the bubbles too, since flat coke does not have the typpical 'sting' normal coke has. I go for a mechanical reason: I used to have a fishtank with bubbles coming out of the bottom, occasionally they would attach themselves to little 'rocks' (the kind you put in your tank to make sure the waterplants can root) and lift them up, they didn't push them up but they really lifted them up like a balloon can carry a basket. This force the bubbles put on the substrate they are formed on combined with the force produced by the local pressuredifferences created by the forming bubbles can pull or press on your tongue-cells and agitate them. Maybe this is what causes the 'sting'.