To slow down the fermentation process of a food in a can
Masi,

Given that I'm a severe allergy and migraine sufferer, I was surprised by your assertion that canned foods in general contain large amounts of histamine.    As far as I can find from internet search, they do not.  The canned/jarred foods which specifically have been measured to contain histamine are:


canned fish, especially tuna
canned tomatoes
fermented vegetables, especially saurkraut
fermented soy products, especially soy sauce and tofu
red wine and red wine vinegar (and anything pickled in wine vinegar)


The answer is simply: don't eat the above if your sensitive to histamine.  You can avoid them.  Also, the histamine in the above foods already exists in the can or jar before you buy them, and will not be reduced using salt or chilling.

I am quite puzzled by the inclusion of canned tomatoes on that list, but several sites reference it.

Part of your confusion is clear with this statement:


  Histamine is created as a result of fermentation so can-food has
  significant amounts of histamine compared to non-can-food. Assume we
  have food in a can. It ferments all the time little although it is in
  a salt liquid.


Um, actually, no.  If your can of corn is fermenting, it's bad.  Throw it away before the can explodes.  Canned and jarred fermented foods are fermented before they are put in the can or jar.  Cans of non-fermented foods are not going to ferment on you; they are heat-treated to destroy all microorganisms which would cause fermenting.

Further, histamine is only created as the by-product of the fermentation of certain proteins or fibers, so not even all fermented foods have it.  There is a larger list, though, of foods which stimulate histamine production than which contain histamines.

References on which I base the above statements:


http://www.reverta.com/blog/histamine/top-10-histamine-containing-foods/
http://www.cfs.gov.hk/english/programme/programme_rafs/programme_rafs_fc_01_04.html
http://www.allergyuk.org/fs_histamine.aspx
http://nchfp.uga.edu/how/can_home.html


One thing which is interesting and irritating is that while there have been numerous studies showing that canned fish can contain deadly levels of histamine (because of the decomposition of the fish before canning), several nutritional information sources have apparently taken to restricting all canned foods "to be safe", presumably since they don't think their readers can differentiate between tuna and green beans.  This is presumably the source of Masi's confusion.  I spent some time searching for any studies indicating the presence of histamines in canned vegetables or fruits, with no results.

If an actual nutritionist or biochemist is reading this question (I am neither), please add to what I have above or correct me.  Thanks!