Unless the tops of the cans are bulged,
canned goods remain SAFE to eat pretty much indefinitely. But that doesn't mean they still taste good or even look good. Time and temperature extremes destroy both the flavor and the color of canned goods. I recently opened a can of beets at my dad's house that had been on the shelf for several years without having been subjected to more than a few degrees of temperature change...they weren't red any more, they were gray! And they had no flavor whatever. Don't even consider eating anything from a can that's bulged, even slightly. Although canning "preserves" foods, it doesn't kill the bacteria in them, it just knocks 'em out. Bulging is caused by gasses created by putrifying material in them...it means the canning process has failed and the food inside the can has spoiled. IMHO, you'd eat a whole lot better if you only took what you plan to use each time, and relied more on fresh foods, many of which can last at least a week if brought aboard frozen..
