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Ripening of Bananas with Ethylene-Safe or Harmful

The big question
Many people have asked me whether ripening of bananas with chemicals is harmful to health. I understand their concern. This is because numerous artificial compounds are used in foods nowadays. Again, banana is a favourite fruit to many, so they may want to be sure if it is safe for eating. I will address this question in depth in this article.

The process of banana ripening
During the growth and development period of bananas, there are many chemical and physical changes that occur. These have an impact on the fruit quality after harvesting. Normally, ripening is the final stage in fruit maturation. During ripening, the fruit changes colour, flavour, texture and aroma to optimal eating sensorial and textural properties. The agent that triggers these changes during maturation of bananas is a chemical called Ethylene. Ethylene is a gas naturally produced by plants e.g to trigger leaves to turn yellow and fall off during certain seasons like winter.

What is Ethylene
Ethylene is a ripening hormone – a chemical substance produced by fruits with the specific biological action of accelerating the normal process of fruit maturation and senescence (dying or going into dormancy).
Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, pears, apples, melons, mangoes, avocados and papayas.

Factors that trigger production of ethylene in fruits
-Natural process such as maturation and weather
-Injury-Injured fruits ripen or go bad quickly than injury free ones.
-Attack by insects and birds- fruits eaten by birds ripen faster.

How was the effect of ethylene discovered
Traditionally, lemon growers stored harvested green lemons in sheds which were kept warm by kerosene heaters. Lemons were stored until they turned yellow and ripened for market. However, when modern heating systems were introduced in sheds, the lemons  never turned yellow on time. Research found out that the main factor that influenced ripening in kerosene warmed sheds was the small amounts of ethylene given off by kerosene heaters.

Traditional application of Ethylene in ripening of bananas
When I was a kid, I used to see my grandfather store bananas covered with dry banana leaves. Some times, he used to keep them in a room where fire was lit regularly. These bananas ripened faster than the uncovered ones.

Some communities used to dig a hole, place dry bananas leaves there and burn them. This was followed by placing fresh leaves on top of burnt leaves and then bananas on top. After placing bananas, they again covered with more leaves. The bananas stored this way ripen faster than those which were not covered. What these practices were doing is increase production and accumulation of high levels of ethylene to hasten the ripening of bananas.

There is also a common practice of placing avocados or bananas in a airtight paper bag to hasten ripening. The ethylene produced by these fruits accumulates in the bag, accelerates ripening, the ripening fruits produce more ethylene and the ethylene production process repeats itself.

Sometimes, unripe bananas or avocados are placed together with a ripening passion fruit to hasten the ripening process

Modern Day application of Ethylene to ripen bananas
Once people realized what hastened the ripening of bananas, it was conceived that it is possible to delay or hasten the ripening process. This led to either application or absorption of ethylene from fruits during storage and transportation.

Fruits are normally transported over long distances to reach their intended market. In order for the bananas to survive the transit time from source to the market it must be picked at 3/4 maturity when they appear green. After arrival in the destination country a very small controlled release of ethylene is used to trigger the natural ripening process.

Nowadays, most commercial warehouses, ships and trucks all fitted either with ethylene absorption technology or ethylene generation machines to help control ripening process of many fruits.

Why do supermarket bananas turn bright yellow by the time you get home

I have this experience a lot. I buy bananas in the supermarket which are slightly yellow (sometimes green). When I get home, I am shocked to see them turn bright yellow within few hours. This is an effect of ethylene. Probably, they were applied with ethylene immediately prior to shelving.

High levels of Ethylene in Kitchen appliances

A refrigerator is one of the kitchen appliance that might have high levels of ethylene. When fruits are stored in the refrigerator and it is kept closed to retain the desired temperature, it also enables an increased concentration of ethylene to accumulate. Therefore, when fresh fruits are brought in, they ripen quickly and go bad instead of storing for long.

Advantages of using controlled Ethylene to ripen bananas
Ethylene helps to regulate the ripening process. Therefore without ethylene the ripening process in uncontrolled. This has many disadvantages:
-Presence of uneven ripened bananas.
-Requirements for regular sorting to separate ripe and unripe.
-Ripe bananas would go bad within a very short period if exposed to uncontrolled ethylene.

Disadvantages of Ethylene ripened bananas
Normally, bananas ripened by application of external ethylene lack that characteristic flavour and aroma of naturally ripened fruit. But they are in no way inferior in terms of nutrients.

Fruits and vegetables that are sensitive to Ethylene

Ethylene is good but can accelerate aging and eventual spoilage of many fruits and vegetables. Therefore it is advisable not to store ethylene-sensitive fruits and vegetables together with ethylene releasing fruits. Some of ethylene-sensitive vegetables are: broccoli, cabbage, cauliflower, lettuce etc.

Does use of Ethylene allow ‘cheating’ of consumers
As a personal view, I do not think this is possible. Although ethylene can be used to ripen immature fruits due to greed of profits, this in no way amount to cheating.

Is use of Ethylene an ‘artificial’ process

No! Ripening of bananas with ethylene is not an artificial process. Ethylene is just used to slow, hasten or regulate a natural process. Ethylene in itself is a naturally produced gas. Even without additional of external ethylene, fruits will produce it any way.

Is ethylene a harmful compound or toxic to human health?

No!. So far, ethylene is a natural gas which can be manufactured artificially and has not been found to have harmful effects on human health.

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Comments on this entry are closed.

  • Nimoh Kaiyehe April 21, 2010, 4:22 pm

    wow,,am quiet enlightened on this process i always wondered why the bananas ripened so fast & i always blamed the heat of this place but huh!now i knowThanks so much every time i read your notes i go one mile ahead,,,keep em flowing.

  • Beatrice Kaiyehe April 21, 2010, 4:22 pm

    wow,,am quiet enlightened on this process i always wondered why the bananas ripened so fast & i always blamed the heat of this place but huh!now i knowThanks so much every time i read your notes i go one mile ahead,,,keep em flowing.

  • Elda Tata Masake April 21, 2010, 5:47 pm

    Wau! I never knew fruits continue to ripen in the fridge…. Am more informed now

  • Fiona Maore April 21, 2010, 5:56 pm

    U don knu ow much u hav enlightened me.thanx alot.i now hav answrs 2th querys hav bn askng myself.thanx

  • Bessy G N Kirimi April 22, 2010, 4:15 am

    Thanx u enlighten me every time barikiwa

  • Mitine Helen Mwari Mitine April 22, 2010, 10:47 am


  • Mitine Helen Mwari April 22, 2010, 10:47 am


  • Steve Muthusi April 22, 2010, 4:18 pm

    Enlightening indeem.

  • faith April 29, 2010, 3:05 pm

    That was what I really wanted to know. I can now eat any bananas without worry. Thanks for enlghtening.

    • Joshua Arimi April 29, 2010, 3:26 pm

      I am pleased to hear that you got the information that you had longed for. Enjoy all bananas with peace of mind. Ethylene is safe in levels used for fruits.

      • ashwini March 19, 2011, 7:54 am

        Hello i am doing a project on effect of ethylene on banana could you help me please with some information. Thanks

        p.s. oh yes i almost forget im from Maurtius

  • Peter Evans May 25, 2010, 9:03 pm

    Excellent article.
    If you want to see Ventech Ethylene Generators in action, go to Sunny Processors in Nairobi.
    You are also welcome to contact me for more info or prices on ethylene generators

    • sajad August 29, 2010, 11:47 am

      hi dear
      i am sajad from Iran .we act about import fruit to Iran we need ethylene generator .can you give me more information about your equipment.

      • Bobby July 12, 2012, 2:45 am

        Good day, Sajad!

        If you are into commercial banana importation, ripening and marketing, I am available to be your consultant/technical adviser. I have more than 20 years experience in banana production, shipping and handling as well as ripening. I also worked in Jebel Ali, Dubai, UAE in this respect. You may contact me at: fbrlead@yahoo.com

  • Suvarna lakshmi September 11, 2010, 11:50 am

    Sir, what you said is correct with respect to the fruits ripened using ethylene. But what about fruits readily available in the market alike normal fruits, ripened using dangerous chemicals like calcium carbide and others? I would be grateful to you if you can elaborate how to escape from these chemically dominant fruits.
    Thank you

  • ashwini March 19, 2011, 7:50 am

    Hello i need some clarification on recommended concentration of ethylene on banana and its potentaial side effect on the fruit itself and human beings. Also what are the methods used to analyse ethylene concentration on bananas?

  • janny November 8, 2011, 1:05 pm

    I did not know all about this ripe banana! Thank you for informing me!

  • Julius A. Ombayi December 6, 2011, 11:32 am

    Thanks for the information.Infact I was doing a research baout artificial ripening,especially on bananas!Now am fully well informed:)

    Julius from Kenya.

    • Joshua Arimi December 31, 2011, 7:55 am

      You are very much welcome Julius.

  • mami June 8, 2012, 2:45 pm

    Hi Sr, I am thankful about the information you post. But I need more information about ethylene generators. In what forms are there in the market. I am planning to do project on it, thus I need information about the size, form and the price. And what about Ethephon? Is that harmful? Thanks!

  • jeshrel Plaza July 22, 2012, 4:44 am

    sir just asking, what other fruits can produce more ethlyne during their ripening stage?

  • jeshrel Plaza July 22, 2012, 4:47 am

    im from philippines, just asking if what other fruits, aside from apple,pears,
    can produce more ethylene during their ripening stage?

  • Diya grewal August 10, 2012, 1:08 pm

    I like your artcle…it is very helpful for me as my father has planned to put up a “COLD STORAGE”.As he is a bussinessman (fruits and vegetables) in haryana.I want to know how ethylene is produced…I mean if we want to synthesize it at home…or is it available in the marcket?Since in our store the colour of riped banana is not yellow….nd we are worried bout that..can you please suggest any solution for that….please keep going on like taht..

    • Prakash Kumar December 4, 2012, 10:58 am

      Well you can get ethylene gas cartidges available in India . You can ripen on ur own fruits under cold store.

  • Edward August 24, 2012, 11:48 am

    I like your article.

    Thank you

  • Elena Rod-Armstrong August 29, 2012, 6:45 pm

    Dear Dr. Armi,
    Loved your informative article on the use of chemical “ethylene” (naturally and artificially produced) for speeding up the ripening process in the banana industry. Although I agree with you on it being part of a great technology being employed in the commercial marketing of friuit produced in the world.

    Let me relate what led me to investigate this topic, and thereby finding your site: Being a health-conscious senior lady, but with high cholesterols, and disliking the usual medications offered, I opted for the “diet and exercise” plan. So, lately, I am using my blender for making healthy and delicious friut smoothies. Naturally, my main choice of fruit is the “banana”!

    For the past couple of months I have been having a pitcher-full of mixed fruit smoothies, that includes banana mixed with other fruit (canned pears or “canned” peaches – these already come sweatened and are cut in half for easy blending). Along with any type of juice for liquid part ( I do not take milk), along with some ice cubes, and that’s it. A quick and easy recepi, and with an added caribbean spice of: sprinkle of cinnamon, a dash of vanilla, and a tsp of sugar if desired. That is the custom in Puerto Rico where I have lived for the past sixteen years.

    Yesterday, I was eager to make my daily fruit smothie using the fresh bananas just brought in from gocery store the day before. They were a little bit green at the tip of the stalk, and bright yellow … which I took to mean that they were realy fresh! In fact, as I was entering the gro. store, I noticed the produce clerk stocking piling them onto shelf for sale. I, of course, selected the first bunch on top which had just been delivered.

    The next day, for brunch, I decided to have sliced bananas with oatmeal. Great combination, especially with cinnamon flavored oatmeal! About 3 hours later, I suddenly developed severe episode of shortness of breath, nausea, weakness, palpitations with chest tightness. I could not breathe! My chest began to feel tighter by the minute with my whole body going limp, as I was sweating profusely. I litteraly collapsed.

    I live alone, but have contact of a neighbor lady whom I called for help. I knew I had to get to the hospital as soon as possible. Having no auto, and relying on the bus. Ths was out of the question. I could barely walk. With my last threads of strength, I got dressed and prepared my bag, got my keys, closed up my place and dragged myself outside where my neighbor friend came to help. She offered me a breathing puff with her asthma pump, and this helped me regain a breath a little continued gasping for air. I knew I couldn’t wait much longer for help as we struggled for what seemed a very long time to find a way to the hospital. I was in panic and turning blue, on the floor. There was no one around help with a car to take me to hospital for emergency. At the time, I had no cash on hand, an ambulance was in order, but out of the question. It was difficult to even think and function in order to save myself. So, I just prayed.

    It occured t me that taking a taxi to the hospital was an option. After borrowing ten bucks from the mini-market cross the street, I proceeded calling a taxi. Within a half-hour, I was in the emergency room, where I arrived barely walking and vomiting as they were taking vitals. This was at about 4:00 PM. The nurse was shocked and jumped back from her seat as I lunged forward toward the trash can behind her. I had projectile vomiting for about 10 min. and what I could see in the trash can was white stuff, like “bananas and oatmeal!” The nurse stayed with me. I remained weak and trembling from the weakness, but immediately thereafter, I began to breathe easier. I was observed for a couple of hours or so, as I slept.

    It was around 10:00PM that the bloodwork results arrived for the ER doctor to evaluate me. I was treated with an injections for stomach ailment and nausea symptoms.

    After I explained to the doctor that I had no problems eating bananas straight from the farmland plant where it is grown, right here in Puerto Rico. Her reply was: Grow your own banana plant! At first, I felt insulted at her making light of my close-to-death experience! But, actually, she made a good point!

    Dr. Arimi, thanks for your article on this topic. I am learning that there is a great difference between “native” fruits and store-bought ones! I have actually had these attack episodes of banana gas toxicity before. But, this has been a worse life-threatening experience as a result of high ethylene gas levels. I will not stop eating bananas? But, not from the grocery store!

    NOTE: You say, that “this is NOT an articial process”. I disagree. Anything that has man’s hand in it is artificl. It involves changing the natural organic process — whether accelerating or decelerating the natural process; this is still an artificial means. It is a successful tool for markets to employ this technique: the hurry-up grow and mature by “my” means, so I can excel in my business.

    What a shame to poison the fruit for my consumption. My digestive system couldn’t tolerate this poisonous banana, and I almost died of a cardiac arrest! I’m aware that you glorify this “ethylene” gas as such a wondrous by-product, to be utilitzed in so many ways with our fruit, when in fact, it is more of a “waste, toxic ” type of gas. Maybe the content level of ethylene was too high? What a magnificent thing the body is! It really heals itself. I had to struggle to breath for what seemed an eternity, but hung on a thread while the body was doing its thing. It was gathering all of its strength in order to expel that horrific gas explosion I had in my gut! After the vomiting, my body was left like a limp washcloth!

    This is what led me to investigate the effects of this substance, ethylene, and learned about its uses and effects. Thank for your insightful article.

    p.s. As I had bought a whole bunch of bananas, and only ate one.. these were large ones, I have decided not to consume the rest, but will give them to a neighbor. But, first I have placed them in a bucket of water to maybe dissolve or get rid of excessive gas product?
    What do you think?

    I always knew that produce makets and wholesalers used some sort of chemical on their fruit, but I was under the impressiion it was for “retarding” the fruit, as bananas do ripen quite fast normally. Thanks to your article, Dr. Arimi, I have learned a lot and have been enlightened on this topic.

    • Pietas October 15, 2013, 6:42 pm

      How do you know it wasn’t due to pesticide toxins that you could have had a severe reaction to?

  • jessica September 2, 2012, 5:31 pm

    This site was such a help for me cause i am doing a science project on the ripening of bananas!!! Thanks a bunch!

    • stefan October 4, 2013, 1:49 pm

      hi, jessica, im interested in your study results … thnx

  • Kenzy A. March 5, 2013, 6:27 am

    It’s pretty awesome when all my research about Ethylene is answered on one short, straight forward article!
    Thank you for posting this!!

  • Derek Townshend March 28, 2013, 10:27 pm

    I am curious to know whether the ethylene applied to fruit is a petroleum by-product and therefore may have numerous impurities like sulphur. Who regulates the quality of the ethylene used?

  • Emmanuel kibet June 19, 2013, 12:02 pm

    i love the article sir, am now enlightened more on this banana issue…thanks alot for such interesting information

  • Frits Popma September 3, 2013, 5:47 pm

    Never, never store bananas in a fridge, has nothing to do with ethylene. Bananas are very sensetive to temperatures below 13,5 degrees C. And ethylene only works when pulptemperatures are above 14,5 degrees C

  • Daisy October 1, 2013, 11:30 am

    hello can you help me to know what are the advantages and disadvantages of ripening room? thanks

  • Mar November 24, 2013, 4:51 pm

    Ethylene is a corn based product so every time you eat one you are consuming GMO. I cannot eat corn & many others cannot either so yes this is a harmful process!!! I cannot find a naturally ripened banana so they make me sick – thanks a lot!!

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  • allen January 6, 2014, 8:37 pm

    Great article . They left out 1 thing. Ethylene gas was used as an anthestic in the last 1800’s

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