To keep your avocados (and guacamole) fresh and tasty, you need to prevent it from coming into contact with oxygen. (nutritionrefined.com)
I am not a scientist but I figured the apples turn brown from contact with oxygen, so could the ginger be protective? (nutritionfacts.org)
The bacteria on the edges of the film can be easily exposed to oxygen, but those further inside the film might not come into contact with the oxygen. (sciencedaily.com)