I have a lot of canisters, as well as various-sized canning jars. We save a lot of stuff in them. However, I only have a few canisters that would be big enough to hold a 5-pound bag of flour. The big ones are expensive, and they take up a lot more space than just the bag. I need to store some of these things in a drawer that is really crowded.
Also, I need to have a LOT of storage bags or canisters because I try to keep a bag of both all-purpose and bread flour in the pantry; masa harina for the Mexican dishes; whole wheat flour; bread flour that is opened; and more. I need to store at least ten different things, which would be a lot of canisters. Also, as good as canisters are, the vacuum bags do a better job of preserving things, or at least that is what I have found. I don't know how many molecules of oxygen are left in a canister, but my sense of things is that there are far fewer molecules left in a properly evacuated and sealed bag.
BTW, if you use canisters, and if you have a Sodastream carbonation device, one trick I came up with, which works
amazingly well, is to fill the canister with your food, and then squirt a little carbon dioxide from the Sodastream into the canister. If you do a little research, you'll find that a lot of produce companies use CO2 (as well as nitrogen) to extend the life of their product. I have used this for strawberries, and the results are absolutely amazing. I can keep them for several days with only a minimal loss of product quality. Strawberries are among the most perishable of foods. For strawberries, I simply add the CO2, and then evacuate the canister for less than one second, just enough to keep the lid on, but not enough to disrupt the strawberry's cell structure (i.e., not a full-blown vacuum). I've done this with lots of other things, and it often works better than creating a vacuum.
I haven't come up with anything for storing bananas for any length of time.
I also have purchased the
oxygen depletion packets[/COLOR], but don't yet have mylar bags. I know a few survivalists, and they use the combination of dehydration, vacuum, gas, mylar, and oxygen depletion packets to store their stuff for years at a time.