Going Bananas

by kwolosz on September 25, 2012

Fishy Bananas? Photo: Henrik Sorensen/Getty Images


As a vegan, food has become an overly obsessive topic that requires planning and preparation. I know where I can eat, what I can eat, but more importantly, I have my own ‘safe’ foods that for some reason create a calming effect on my non-stop “is this vegan?” quest.

Fruits, vegetables, and legumes (nuts) have always been considered my ‘safe’ foods. I once survived two days in a remote town on just apples and seeds, not for any weight-loss motive, rather because I was unfamiliar with the restaurants and food environment. But as always, my good ole’ staple foods promised some sense of security; that was until now.

Vegans, for some reason, get a bad rep. But think about it. How easy do you think it is to live this lifestyle without any support from the community at large (i.e., government and/or policy)? As if it isn’t hard enough, scientists at the National Meeting & Exposition of the American Chemical Society recently announced a new spray-on coating that can delay the ripening of many fruits and vegetables. First on the chopping block are the reported 6.4 billion bananas consumed each year in the United States.

First thought, okay- this will alleviate my need to buy bananas when they are bright green, brown bag them until they are near rotten and then ultimately create a panic to bake banana-anything and everything. But similar to all scientific innovations, this comes at a cost. The spray used is called chitosan, a chemical derived from the shells of crab and shrimp, which challenges those practicing an animal-free lifestyle and those who suffer from a shellfish allergy (one of the most common allergies in the U.S.).

The chitosan-based spray is intended to kill bacteria on fruits and vegetables that promote rotting by slowing the ripening process, both of which are naturally occurring processes. Thankfully, this chemical is only in the conceptual phase and yet to be used commercially. Ideally however, this chemical is cheap, accessible and typical to the American diet. Bon Appetite!

Source: ScienceDaily. (August 22, 2012). Good News for Banana Lovers: Help May Be On the Way to Slow That Rapid Over-Ripening

Image: Henrik Sorensen/Getty Images (2012)

Quintus September 25, 2012 at 1:00 pm

Interesting post. My wife is a Vegan and always has great problems getting something to eat. The restaurants don’t cater for such a minority.
A couple of points: Chitosan may challenge those on an animal free diet, I agree, however it is obtained from the shells of crabs etc and not eaten therefore I don’t think it will affect those with shellfish allergies. Especially as it has plenty of other sources.
The other point is the ripening process is not caused by bacteria. The compound responsible for this is ethylene, a natural ripening plant hormone. One can measure it emitting from bananas and if you place an unripe avocado in a bag with a banana it will rapidly ripen. So by covering the fruit or vegetable in a non permeable chitin skin will actually hasten the ripening process by maintaining the ethylene atmosphere.
Bacteria and mould will take over when the rot sets in.

John Spevacek September 25, 2012 at 1:54 pm


The researchers reported that the chitosan hydrogel slowed down the respiration of the fruit (O2 out, CO2 in) which slowed down the entire metabolism of the bananas, which I assumed means a slower ethylene production rate.

Quintus September 25, 2012 at 2:25 pm

I’m not an expert on this topic, here is a quote from the Wiki page:
“Ethylene is biosynthesized from the amino acid methionine to S-adenosyl-L-methionine (SAM, also called Adomet) by the enzyme Met Adenosyltransferase. SAM is then converted to 1-aminocyclopropane-1-carboxylic-acid (ACC) by the enzyme ACC synthase (ACS). The activity of ACS determines the rate of ethylene production, therefore regulation of this enzyme is key for the ethylene biosynthesis. The final step requires oxygen and involves the action of the enzyme ACC-oxidase (ACO), formerly known as the Ethylene Forming Enzyme (EFE). Ethylene biosynthesis can be induced by endogenous or exogenous ethylene. ACC synthesis increases with high levels of auxins, especially Indole acetic acid (IAA), and cytokinins. ACC synthase is inhibited by abscisic acid.”
So , if it slows the rate of O2 transfer to the outside the rate of ethylene synthesis should continue.
In any case it is an interesting topic.

kwolosz September 25, 2012 at 4:06 pm

Yes, this is a very interesting topic. The research is still on-going and the medium for which this preservative was presented was a ‘sci-fi’-type platform. There is still a lot of research to be completed before any causal relationships between allergies can be understood.

kwolosz September 25, 2012 at 1:16 pm


Thank you very much for your feedback! I can sympathize with your wife- eating a pure vegan diet is a challenge.

The article I looked at explained Chitosan as possibly affecting those with shellfish allergies, but it was more of a correlation rather than a causation. There is still a lot of research on this chemical and its role in the food industry.

Thank you for the comments!

Margaret Freaney September 25, 2012 at 1:22 pm

As someone with a severe peanut, and a mild shellfish allergy, this post caught my interest right a way. I also have to obsess about each ingredient that goes into my mouth. I have lived for three days on nothing but water, bananas, and hard-boiled eggs, since those were the only things I knew could not be cross-contaminated. I don’t know about how strict some vegans are, but most that I have met would be more bothered by a chemical on their bananas then that it was made with shellfish parts. I would be more worried about the allergy, though I don’t know enough about which proteins are in chitosan and if they have been linked to shellfish allergic individuals. Do you have that information? Are there more studies about if the chitosan would affect the produce in any way? Thanks for your first post!

kwolosz September 25, 2012 at 4:11 pm


Thank you! Yes I was very shocked as well about the potential usage of this product on our food system.
There is still a lot of research that needs to be done. Before I made my initial comments about allergies, I should have stressed that this preservative is still in the initial testing stages and there have been no causal relationships, only assumptions.

John Spevacek September 25, 2012 at 1:52 pm

A nice I never thought of the vegan aspects of this approach. I liked the article a lot, but thought that the bridge that started in the third paragraph and went into the fourth as well was rough. It made it tough to see where you were going. I ultimately liked it, but

Like Quintus, I was somewhat surprised about the shellfish-allergy connection for a couple of reasons. First, the chitan is chemically modified using strong solutions of lye to make it into chitosan. Chitin isn’t water-soluble/dispersible (which every crab, lobster and shrimp is very thankful for!) while chitosan has been so greatly modified that it is water-soluble/dispersible, But also, I would have thought that the allergic reaction came from the flesh and not the shell of the crustaceans. Not being allergic, I could be wrong on this.

kwolosz September 25, 2012 at 4:16 pm


Thank you very much for your feedback – I appreciate it!

I do agree with you that I should have gone more in depth regarding the scientific background of the chemical. I also should have stressed that the research is still on-going, and that the relationship with the shellfish allergy is just an assumption. I do not have a strong scientific background, and therefore I did not feel comfortable trying to explain the chemical reactions of food science, or of Chitosan.

However, I will take this comment as ‘food for thought’ (no pun intended), and tackle future topics with more scientific evidence for support.

Jennifer September 26, 2012 at 4:34 pm

unfortunately, it would definitely be possible for the shellfish-allergic to react to this product. it may only affect the extremely sensitive, but we won’t know until it winds up in the food supply (because odds are good any studies pre-market won’t be sufficient) and by then it’ll be too late. it’s also possible it’ll create MORE shellfish allergies through constant low-level exposure for people who work with this chemical every day by packaging our bananas or stocking them in stores, or people who consume bananas regularly.

i think it was a poor choice to start with one of the “Top 8” most common allergens for this research (especially since banana ISN’T a top allergen, and is a safe food for many people, from vegans to those with allergies, and that allergies are on the rise), but I’m hoping the researchers will find a more suitable source for this product, if they decide to pursue it further. (I’ve read they do actually want to do this.) If this product reaches the market and it’s still shellfish derived, I think that’ll be very bad science, and very irresponsible.

Emilie Reas September 25, 2012 at 3:13 pm

As a vegetarian verging on vegan, this was a really informative and valuable post. It’s always disturbing when you learn of hidden animal ingredients in your food, and there’s a definite need for greater transparency. I enjoyed how easy to read and direct your post was, although a few more details could have been useful. In particular, I was initially unclear about the context in which chitosan would be used. It first sounded like it was some sort of pesticide and it wasn’t entirely clear whether the delayed food ripening was the purpose, or an unintended consequence. The link to the Science Daily article was useful, as it clarified that the coating would be used voluntarily by individual consumers. Overall, an interesting topic and good post!

kwolosz September 25, 2012 at 4:22 pm


Thank you! I wish you all the luck with your transition to veganism! I am lactose intolerant, therefore going vegan was not that difficult since I can’t eat dairy . From what I understand, giving up cheese and ice cream is the biggest hurdle for most, but you can do it!

The topic of Chitosan and the effects are unclear, which was obviously portrayed well in my posts, considering that many people are commenting on the same thing. The research is still on-going, I should have stressed that the preservative was presented at a conference for innovative initiatives that are just in the conceptual stage. Since I don’t have a strong scientific background, I didn’t feel comfortable explaining the food science behind the topic. However, the issues raised about our food system was the most interesting to me.

Michelle September 25, 2012 at 8:06 pm

Greetings Kwolosz

I believe I am still on the review panel for these articles from last semester! I am a professional editor and technical writer so I will concentrate on those aspects.

This is a really interesting topic and I think it would have an interest factor for most people – fishy bananas! It is probably most suited to a casual magazine or popular health site as you have injected a lot of personal health experience. This is great assuming that is the audience you are writing for.

You do not introduce the topic of the article – the fishy bananas – until paragraph 3 when it really needs to be right up front in paragraph 1. Even a simple line such as “As a vegan I was alarmed to hear that bananas may soon come with a shellfish coating”. I think you have potentially narrowed the interest group for the article too much and are likely to put off vegan-averse readers. (As a clue, a major reason vegans get a “bad rep” is that they never stop talking about their lifestyle choice and how hard it is for them.)

Try to split some of your sentences to make them a little punchier (one idea per sentence) especially if this is to be published online. Overall though I really liked your personal interest angle and you have some snappy phrases in there that show a good ability to write science for a popular audience. Good luck!

kwolosz September 25, 2012 at 8:24 pm


Thank you very much! As the day winds down, I am starting to reflect on all of the comments – good and bad. I am very thankful to have such a broad audience that come from such a range of expertise. As a first time blogger, this being my first post to go ‘viral’, I am very gracious for all the constructive criticism I have received today – it will definitely help me grow as a writer.

I look forward to your input and advice in the weeks to come!

Patricia September 25, 2012 at 10:52 pm

Nice post.

I’m not a Vegan, and live in other country (not US) but have friends that suffer from that. We have a lot of fruit, but knowing there is some new spray that can delay the ripening of fruit gives good alternatives to countries where getting fresh fruit is difficult.

The seashell issue has to be considered, but mainly because of the allergies. I don’t think it wil affect your diet.

kwolosz September 26, 2012 at 6:08 pm


Thank you for the comment. Yes being vegan is a challenge but it is a lifestyle choice. When I came across this topic, I couldn’t help but write about it. Food science in general is a very innovative topic that is still continually changing. While I am thankful for many scientific discoveries, I sometimes wish they would just let food be food!

Jennifer September 26, 2012 at 4:41 pm

I’m vegan, too, and I was horrified to hear about this awhile ago. I’ve also got allergies plus celiac disease, and the thought of putting one of the 8 most common allergens on one of my favorite foods just disgusts and horrifies me.

Using an animal product doesn’t surprise me, because Big Food is constantly looking for ways to profit off waste products. (Beaver anal gland secretions for artificial vanilla and strawberry flavor, anyone?) The fact that they’re starting to taint our vegan food supply is just more of this, and it’s not cool, even if it’s not surprising. But to do so with a common allergen is so irresponsible and infuriating. luckily this is many years away from going to market.

Interesting post!

kwolosz September 26, 2012 at 6:12 pm


Hello fellow vegan! I am glad that my posts appeal to both the vegan and non- alike. Food is a very sensitive, but important issue to understand considering that while we all may not have the same palate, we do all eat. Our food system in general has gone so far from natural that many people do not even know that a majority of food in the US is genetically modified (GMO). This brings up the issue of organic vs. non-organic and for me, just makes buying organic and/or local more important than ever.

Thanks for reading!

Angela October 2, 2012 at 9:17 am

Thanks for the post! I think it’s a good idea to start from a personal connection with the subject. I would have liked to see more information on the chemical, though, and perhaps whether the chemical is already causing controversy. Especially how the chemically is harvested, whether ethical guidelines have been established or whether it can be synthesized.

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