Science may have the solution: a chemical "hydrogel" coating
made from chitosan, derived from the shells of crabs and shrimp.
Chitosan is already sprayed on lots of other fruits and
vegetables to kill bacteria and keep produce fresh. And on
Wednesday, Xihong Li of Tianjin University presented data at a
meeting of the American Chemical Society showing that it can
work to delay banana ripening -- bad news for fruit flies, good
news for you. "We found that by spraying green bananas with a
chitosan aerogel, we can keep bananas fresh for up to 12 days,"
Li said in a statement Wednesday. "Such a coating could be used
at home by consumers, in supermarkets or during shipment of
bananas." Like other fruits, bananas don't die when they're
picked. They respire through their skin, taking in oxygen and
expelling carbon dioxide. Increased respiration means quicker
ripening. The chitosan coating used by Li and his colleagues
slowed down respiration enough to keep the fruit fresh. Bananas
also release a compound called ethyl