Last time I checked the air was about 80% nitrogen.
Storing a banana next to a mango won’t do much.
It would be really helpful if you linked to whatever you’re commenting on so I have some context for your statement.
I assume he means this column about refrigerating bananas.
How much nitrogen is in the air is irrelevant. Ripening fruit give off ripening agents like ethylene and keeping ripening fruit together increases their exposure to the ripening agents.
The questioner was possibly confused by the fact that when bananas are shipped long distances, they’re in a pure nitrogen atmosphere. This unsurprisingly slows their ripening, as nitrogen is quite unreactive.
Whereas oxygen, most of the remainder (like 21%)…almost the very definition of reactive.
By the OP’s logic, there’d be no difference between breathing normal atmosphere and breathing pure nitrogen, so inert gas asphyxiation would be a pretty ineffective form of execution.
He’s talking about the comment in the question by David Grodsky:
If a ripening banana gives off nitrogen, will lowering the nitrogen content around it keep it fresher? That’s what David’s coworker thinks.
The OP’s logic is perfectly sound; the presence of large amounts of nitrogen in the air logically excludes any effects from any (imaginary) nitrogen emissions from the banana. And as Chronos has said, nitrogen inhibits ripening.
The gas that ripens fruit is ethylene, as Tripolar mentioned.
Most fruits, except mangos, pineapples and citrus fruits, produce ethylene.
It’s not nitrogen that inhibits ripening but the lack of oxygen. The final step of ethylene biosynthesis requires oxygen and removing it stops ethylene production and hence ripening dead in its tracks.
Any inert gas would do, although I’d advise against xenon, as it is a potent anaesthetic.
Le Chatelier would tend to disagree. If we stipulate that ripening bananas generate nitrogen, then surrounding them with pure nitrogen should inhibit ripening. I haven’t accepted the first premise, but if it is true, then the second should follow.
Doesn’t work. Ripening bananas (or nearly any other fruit) do in fact generate ethylene, and surrounding them with pure ethylene encourages ripening.
Which incidentally leads to the question: Why is ripening encouraged by a gas produced by ripening? Presumably, there’s some benefit to the plant for all fruit in a region to ripen simultaneously, and so this gas system evolved, but what would that benefit be? I can’t think of any explanation consistent with the fruits also evolving to be good food sources for animals.
I’d avoid radon as well.
Read my post again more closely. I did not say surround the banana with pure nitrogen. I did not even say increase the nitrogen around the banana. I said pair the banana with an unripe mango, which absorbs nitrogen. Ergo, there is less nitrogen around the banana. According to Le Chatelier’s principle you cite, that should make the banana ripen faster.
Many fruits include the seeds but also a fleshy coating. The fleshy coating encourages being eaten, thereby breaking up and spreading the seeds, or perhaps passing the seeds through the digestive tract to be spread elsewhere.
Having all the fruits ripen at once means more animals drawn to area, thus more distribution.
That only works if you can draw in enough animals to eat all the fruit, and even then, the animals still have to get there at the right time, and then get someplace else to eat the fruit there so they don’t starve. It seems like it’d make more sense to have a smaller food supply for the animals that’s steady over time, from fruits ripening at different times.
I would like to know by what mechanism an unripe mango absorbs nitrogen, and what happens to the spectacularly unreactive nitrogen gas once it is absorbed by the unripe mango. Have you discovered a new method of nitrogen fixation?
It doesn’t, but someone somewhere along the line had the impression that it did, and we’re exploring what implications it would have if true.
However, most of what was originally said about nitrogen is actually true if we replace it with ethylene instead.
Well, then. I’d also like to know how a banana generates nitrogen. As far as I know, only certain bacteria can perform denitrification, i.e., reduce nitrates back into nitrogen, and only under anaerobic conditions. If you’ve discovered that a banana can do this, in the presence of oxygen, no less, you’ve made a monumental discovery.
Come to think of it, the magical nitrogen-fixing mango is surrounded by huge amounts of nitrogen in the form of the atmosphere. In order for the magical denitrifying banana to have any effect in the supposed nitrogen-activated ripening of the magical mango, the magical banana would have to pump out nitrogen at a prodigious rate.
I agree. However, some plants do have a weird synch cycle that works to their advantage, but also spawns a surge in animals eating them. Witness bamboo, its weird mass flowering cycles as long as 150 years, where all the plants anywhere in the world derived from the same progenitor by cloning will flower at the same time.
Interestingly, this also spawns a massive surge in rat population that devoirs the bamboo, and goes on to March into inhabited areas and destroy crops.
That wikipedia page says a predator satiation hypothesis had been proposed, with the idea the mass flowing assures the predators can’t devour all the seeds. So petals that’s the explanation. Create more fruits and thereby seeds than can possibly be devoured and increase reproductive survival.
It is not my proposal or claim. It is the claim of someone cited by the person who asked the original question to Cecil. I was pointing out what the OP of this thread was addressing, since several posters apparently missed it.
I have no idea, and would love to know where the idea came from. Some old wives’ tale, I guess.
Agreed. I think the claims are ridiculous. Both about bananas and mangoes. I think it is just possible that a paper bag could be used to slightly concentrate a gas being expelled by a fruit, and a fruit that absorbs that gas would be affected by the gas increase. But nitrogen is pretty ubiquitous in the atmosphere, and relatively inactive. That’s why plants need chemical fertilizer - they don’t get nitrogen via the air, but through the roots.