The best way to keep food as that is to put it in a container as airtight as possible. Exposure to the air will make it stale. Any storage should be DRY and do not freeze it as the freezing and defrosting will cause condensation that produces moisture.
Good candidates in order of preference:
-If you have those vacuum sealers/containers those are the best.. The vacuum selaers suck all the air out before heat sealing a plastic bag for excellent airtightness. The containers have a pump that lets you pump out the air to seal it in a vacuum.
-Tightest hard plastic storage containers with lids.
-Ziplock bags
-Your stomach
-Your dog’s stomach