A Brief history of canned food
In 1795, during the Napolenic wars, the French government offered 12000 francs to the person that could figure out a way to preserve food for the military that would not greatly degrade the taste of the food (such as salting or smoking food might). Nicolas Appert, a wine and candy maker, figured out that if he put stew or jam in a glass jar, sealed it, and then boiled it for five hours the food would not spoil and the flavour would not be affected. In 1810 he won the prize and in 1811 he published the eloquently named L'Art De Conserver, pendant plueieurs annes, Toutes les Substances Animales et Vegetales (The Art of Preserving All Kinds of Animal and Vegetable Substances for Several Years).
Appert didn’t know why the food didn't spoil and it would be some time before Louis Pasteur demonstrated that it was bacteria that spoiled food and that the heating process of the canning was killing these bacteria. In 1810 Peter Durand, an Englishmen, invented and patented an iron can plated with tin. In 1813 Bryan Donkin and John Hall, using Durand's patent,
started supplying the British Navy with canned food.
The cans were handmade and required a hammer and chisel to open but they were virtual unbreakable (without the hammer and chisel). The immediate benefits from the canning were for the soldiers in the military who were more likely to die from hunger and lack of nutrition than from the battles. Explorers were another group that immediately benefitted as canned food allowed for easier and longer expeditions, especially of the Northern parts of the world.
In 1812 Appert's book was published in New York and that same year Thomas Kensett started a small factory that packed food in airtight bottles. In 1825 he got the American patent for an improved tin can (Durrand got the american patent in 1819 but this was an improvement on it, I don’t know what the difference was) and started a canning factory in 1839 when glass became more expensive. At this point, in America, mostly oyster and lobster are being canned. Not much is really different now in the world of canning. We are still heating food in airtight containers. Only now its quicker to fabricate the can and heat it.
this is all internet research from trying to figure out what the white stuff inside some tin cans is. Is it paint? what kind of paint and why is it there. what would the advantage of white be. maybe they figure its a more pleasing backdrop for the food and its just a non toxic paint. Or perhaps as some have pointed out it is to prevent the metal from poisoning the food.