Well my question is based on this question down below.

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For those who don't speak german:

You have two potato slices one of them is boiled the other one is just raw.

Now you scatter some salt over both surfaces of the two different slices and wait about one hour.

After the time is over the salt on one potato isn't in his crystalline formation anymore.

So my question is why are behaving both slices different?

My guess is that the carbohydrates ( Starch ) reposition and the starchcores bind with H2O. So the H2O binds with the NaCl?

I would really enjoy it when somebody could tell me the chemical reasons why this happens.

  • $\begingroup$ "After the time is over the salt on one potato isn't in his crystalline formation anymore." But on which one potato the salt will remain crystalline and which one not? (however I'll perform the experiment tomorrow because today I'm going to sleep); but what should be the expected-specification according to your reference? $\endgroup$
    – user25568
    Commented Nov 22, 2016 at 17:38
  • $\begingroup$ As well; to my experience; ample water comes out if I add salt to raw cut-potato before I fry them. But not that way from boiled potato. However if a boiled potato is crushed then again it become soft and moisty; and remain the moistness (doesnot stiffen like a starch gel). $\endgroup$
    – user25568
    Commented Nov 22, 2016 at 17:44
  • 1
    $\begingroup$ I think it should be in Chemistry stack exchange instead of biology. $\endgroup$
    – Tyto alba
    Commented Nov 22, 2016 at 18:05
  • $\begingroup$ I've done the experiment today. Non boiled potato dissolved the large portion of salt within 30 to 45 min. whereas boiled potato just moistened the salt, but not dissolved that way. @SanjuktaGhosh I think this is due to osmosis through cell-membrane whereas boiled potato there should absence of that event due to denaturation of cell membrane. I think this question is appropriate to biology SE. $\endgroup$
    – user25568
    Commented Nov 28, 2016 at 7:43
  • 1
    $\begingroup$ @AlwaysConfused seems far more likely to me that the boiled potato simply doesn't have enough water to melt the salt. $\endgroup$
    – terdon
    Commented Dec 9, 2016 at 12:12

1 Answer 1


Maybe this passage is referring to this experiment?

The key missing from your description is that each potato is placed in water. When the cells are intact (unboiled), this causes water to flow into and out of the cells via osmosis: into the cells from the tray of water, and out from the cells into the salt. Once the cells are destroyed via boiling, there are no intact membranes to cross to osmosis does not occur and the salt remains undisturbed.

  • $\begingroup$ Maybe OP is telling about watery content coming out from cut surface of raw potato but not from boiled potato. But OP is not clear enough about on which-one potatoe the're expecting the dissollution of salt? $\endgroup$
    – user25568
    Commented Nov 22, 2016 at 17:40
  • $\begingroup$ Well sorry if I'm confusing you but I guess you're always confused:P For those who are saying I forgot about the point that the potatoes were placed in water before the salt was scattered. Well that is exactly the problem just one were placed in water and got boiled. The other one was never getting in touch with water. And I don't know if it's the raw or boiled one which changes the crystalline formation. The answer that the boiling destroys the cells and also the membranes which are essentially needed for the osmosis causes the behavior that the boiled let the salt untouched seems legit. $\endgroup$ Commented Nov 23, 2016 at 7:18
  • $\begingroup$ @RonySchmied No I didn't used that added-water outside the potato. But still I got the same result as that youtube link provided by BryanKrause.... raw potato dissolved the salt but boiled (and cooled to room-temp) potato could not dissolve the salt... it just moisten the salt slightly. $\endgroup$
    – user25568
    Commented Nov 28, 2016 at 8:14

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