Stay Fresh vegetable bags are made from low density polyethylene that is coated with a fine layer of natural clay (zeolite) containing high levels of a mineral claimed to absorb ethylene gas.
Ripening is the final stage of the maturation process when the fruit changes colour, and develops the flavour, texture and aroma that makes up what we define as optimum eating quality. The biological agent that initiates this ripening process after the fruit is mature is naturally produced ethylene. While there are other factors involved in this "triggering" of the ripening process by ethylene, it is essentially a universal ripening hormone.
When this internal concentration of naturally produced ethylene
increases to about 0.1 - 1.0 ppm, the ripening process is irreversibly initiated. The process may be slowed, but it cannot be reversed once it is truly under way.
Generally speaking, however, the shelf life of most produce is reduced by storing it in plastic, zeolite or no zeolite, because the humidity inside the bag is so high. You can help your produce last by keeping it cool and by allowing air circulation, which naturally reduces ethylene and other plant hormone levels in the air.
Consumer Reports claims that the green bags don’t do the job
. They performed a test using a variety of fruits and vegetables stored in various ways: they stored the foods in the green bags, in regular Ziploc bags, on a counter, in a fridge and in plastic supermarket bags. They got unfavorable results for the green bags except when it involved bananas, as they report:
From Consumer Reports: We saw green inside the Green Bags, but often it was mold. Blackberries became moldy after three weeks, strawberries and basil after a month, and peppers and tomatoes after five weeks. It was a tough test, but the same foods stored in other ways nearly always had less mold or none after the same time. Only bananas fared significantly better in Green Bags: After two weeks, they were firm and had not turned black.
➥ Debbie Meyer Green Bags
In addition to the Consumer Reports test results, there is a mixed bag of response – mostly negative - from 50 readers at this about.com* blog story written by a chemist who is not convinced. But differences in results, which no one I read has mentioned, can also be attributed to the age of produce when it is purchased, which is unknowable.
* ➥ Do Debbie Meyer and Evert Fresh Green Bags Work?