Mother Nature is the best designer
How do products such as onion, garlic and corn on the cob manage to keep their interiors moist for such long periods of time?
What features and purposes do the materials of natural packaging have?
Corn on the cob is protected by a series of leaves of porous material. The overlapping and porosity of these sheets allow the corn to stay fresh and retain the most water possible for a longer period of time.
As such, it creates an environment from which it is very difficult for water to escape. The same happens with other vegetables such as pods.