Fruit ripening in a paper bag?

[MC Horoscope]

This is making me curious.

You know how you sometimes have to buy a piece of fruit that is not fully ripe yet? I read on another board (not even food-related) that if you leave the fruit out in a paper bag for a day or two, it hastens ripening because the bag captures some kind of gas emitted by the fruit, and that gas (ethylene) speeds up ripening. Supposedly very good with pears.

Is that correct? Can anyone explain this? (Not sure I would trust what "credentialed" Wikipedia posters like shitwhistle32, nedsexy, or 71.136.243.130 have to say about this.)

[TheMatt]

It's correct. Ethylene is the ripening hormone in fruit. This is how industry ripens fruits and vegetables after harvesting them before they're ripe (when they are less prone to damage): they expose to ethylene. And, since many fruits will give off ethylene as they ripen, you can capture that in a bag and do this yourself! Ethylene production also increases with temperature (why bananas get riper faster in summer) and with damage.

If you want your bananas to stay at their current texture, put them in the fridge and they will stop converting starch to sugar. The peels will go black, but the fruit will be fine.

[Pat]

This was discussed at several points during the Post's free range food chat this week.

I often use paper bags to ripen peaches, nectarines and pears, sometimes for avocados. It can be hit or miss, though, especially if you don't check often enough and they overripen before you catch them.

[MC Horoscope]

Thanks! Those links were just what I needed. Depends on the fruit, and you have to be careful of overripening.