I have eaten 17 year-old MRE tuna. The taste suggests a lot of alum but it did not make me sick.
Guess I was hungry.
That tuna as in the packet longer than it was in the sea!.............................
1899-1902 British Emergency Ration Field Service Oldest MRE Beef Eaten Survival Food Review Test
https://www.youtube.com/watch?v=jZoHuMwZwTk
I have been using up frozen dinners that are up to a year out of date and haven’t noticed any difference.
Still not sure if I am going to eat the one that is two years out of date.