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SweetFunnyCool : Here is a simple and easy way to make your bananas last longer. All you have to do is wrap plastic around the stem. Banana stems release ethylene which causes ripening and by blocking the gases from being released the banas could last 3 to 5 days longer

Does the trick work?

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Christian
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1 Answers1

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In this paper from 2006, it states

In the present study, the existence of negative and positive feedback regulation of ethylene biosynthesis is demonstrated in banana pulp and peel tissues, respectively.

So, ethylene synthesis occurs in both the fruit and peel, and if there is any in the stem, it's likely irrelevant since the majority of the metabolically active tissue lies elsewhere.

In the comments to this answer, it has been questioned as to whether the lack of mention of ethylene synthesis in the stem means that it allows this possibility. As explained in the replies, ethylene is lighter than air, so if there is any production there, it can not affect the fruit of the banana as it will rise upwards. But there's another reference here to how ethylene synthesis occurs [2] which negates the possibility of ethylene synthesis in the stem:

Based on our results, ethylene production in ripening banana fruit can be characterized as follows: (a) increase in the abundance of MA-ACS1 mRNA in the flesh is the first step of ethylene induction at the onset of the climacteric; (b) the increased content of ACC in the flesh induces a rapid increase of climacteric ethylene whereby ACC oxidase is activated with the enhanced accumulation of MA-ACO1 mRNA once ripening commences;

And there's an Youtube video that busts this myth

And another bust

[1] Inaba A, Liu X, Yokotani N, Yamane M, Lu WJ, Nakano R, Kubo Y. Differential feedback regulation of ethylene biosynthesis in pulp and peel tissues of banana fruit. J. Exp. Bot. 2006 Dec 21;58(5):1047-57. doi: 10.1093/jxb/erl265. PubMed PMID: 17185740.

[2] Liu X, Shiomi S, Nakatsuka A, [..], Inaba A. Characterization of ethylene biosynthesis associated with ripening in banana fruit. Plant Physiol. 1999 Dec;121(4):1257-66. PubMed PMID: 10594112.

HappySpoon
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  • Maybe the peel of the banana doesn't allow the ethylene to leak outside but the stem does. – Christian Jun 07 '14 at 07:34
  • Can you smell banana anywhere else apart from the stem? If so, you have your answer. – HappySpoon Jun 07 '14 at 07:43
  • Does ethylene smell like bananas? Wikipedia says only that it has a faint sweet musky odor, and that the characteristic banana smell comes mainly from isoamyl acetate. – Nate Eldredge Jun 07 '14 at 20:04
  • @NateEldredge The smell will tell you that gases are being released elsewhere apart from the stem. – HappySpoon Jun 07 '14 at 20:07
  • NB: In the youtube video referenced above, the proximity should not matter since ethylene is lighter than air and so will rise as synthesized. Which is why you hang bananas over a bowl of apples to make them ripen faster. – HappySpoon Jun 12 '14 at 06:53
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    @HappySpoon: the typical banana smell is due to fruit esters (such as isoamyl acetate) not to ethylene. Even if the peel produces ethylene, that does not answer the question of whether the stem does. If that is the case covering it would reduce the amount of ethylene produced, albeit not to zero. – nico Jun 12 '14 at 07:59
  • @nico I suggest you read the reference which I provided, and then comment again. – HappySpoon Jun 12 '14 at 09:21
  • @HappySpoon: I have read that paper before. Still, it does not speak about stem at all, which part are you referring to? – nico Jun 12 '14 at 09:44
  • @nico which is my point. The claim for ethylene synthesis in the stem is not supported in the paper. The synthesis takes place in the pulp and peel. I point to the experiments posted online which I have linked to which show that the trick does not work. – HappySpoon Jun 12 '14 at 10:24
  • @HappySpoon: I am not saying that pulp and peel do not produce ethylene. I am just saying that nowhere that paper shows that the stem does not. Is the stem just a continuation of the peel? In that case it would produce ethylene. – nico Jun 12 '14 at 10:33
  • @nico Let's assume that there is some synthesis in the stem, and that synthesis is related to the volume of metabolically active tissue. Then how would removing the source of 1% or less of the ethylene production affect the 99% production elsewhere? If you need further clarification, please take it to chat. – HappySpoon Jun 12 '14 at 10:36
  • @HappySpoon: you would have 99% of ethylene around, thus slowing ripening by 1%. – nico Jun 12 '14 at 10:38
  • @Nico, that would be incorrect. Since ethylene is lighter than air, it rises so can not affect the other part of the fruit anyway. – HappySpoon Jun 12 '14 at 10:44
  • Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/15061/discussion-between-nico-and-happyspoon). – nico Jun 12 '14 at 13:24