The oxygen in the bucket is driven out by the DRY ICE and that stops all bugs, eggs and whatnot from attacking your food supply. The other method is to put the bucket in the freezer for a couple of days. That kills the bugs and eggs within that you can't see. Keep some food for your neighbors too, especially the older ones who cannot fend for themselves. By stocking up, you will insure that your family can survive as the price of food begins to skyrocket due to real and manipulated shortages.
Canned goods keep well beyond the printed shelf life.
They keep sometimes for many years. There have been some goernment raids as well against some of these distributors. The prices are a RIP-OFF, and so high that the average person cannot hope to own them, nor do they in fact need them. These supplies, on a limited basis, can be mixed in with your other food preparations and made to go three to four times as far as they would if used by themselves. Some are powders you mix with water or fruit juice, others are tablets.