Analysis of information sources in references of the Wikipedia article "Corned beef" in English language version.
Potassium nitrate is used in the manufacture of gunpowder ... It is also used in curing meats; it prevents putrefaction and produces the deep red color familiar in the case of salted hams and corned beef.
The chief use of potassium nitrate as a preservative is in the preparation of 'corned' beef.
you have probably noticed how nice and red corned beef is. That's because it has in it saltpeter, the same stuff that is used in making gunpowder.
Potassium nitrate is used in the manufacture of gunpowder ... It is also used in curing meats; it prevents putrefaction and produces the deep red color familiar in the case of salted hams and corned beef.