Do the new “green bags” really keep food fresh?
The “green bags” are designed for fruits and vegetables that ripen by the production of the plant hormone, ethylene. Ethylene gas is produced in copious quantities by certain fruits, most notably bananas. As the concentration of ethylene gas increases in an enclosed environment, the fruit ripens faster. Removal of ethylene helps keep fruits from over-ripening quickly. The green bags are made of a polymer that allows the escape of the gas while keeping others, and some of them actually use additives to the film to absorb other gases that promote ripening or deterioration.