I use Ziploc gallon storage bags for everything! They keep all the snacks fresh. The only thing I would improve is the durability. I used to be able to was them and reuse them. Lately, when they are washed, they no longer zip closed.
I use this gallon storage bags to put large amounts of food into the refrigerator. For instance, leftover pizza from the box. Also, in the case where you have an open container of sugar, you can transfer the remaining to the ziploc for safe, secure storage!