PROJECT N°35
Effects and Implications of Ethylene Gas
Karmarker Luuk, Leal Mendo
European School Brussels II
Avenue Oscar Jespers 75, 1200 Bruxelles, Belgique
S5 NL
Abstract
In supermarkets, restaurants, canteens and households, an incredible amount of fresh fruit, is wasted
because of spoilage and due to lack of proper storage and preservation. Do people realise that there
are simple preservation methods for hard-earned food. We decided to take on the challenge of finding
a way to save a lot of money and fruit, and at the same time reducing waste, which in turn results in
less carbon emissions. With our experiment, we want to highlight that in addition to traditional cooling
techniques which are very effective, adding a lemon to the fruit kept at room temperature especially
on countertops was more effective in most cases. This means, millions of euros’ worth of savings can
be achieved with very simple techniques. This procedure saves money on cooling equipment, energy
consumption and maintenance costs. Using lemons is a cheap and simple solution. In this paper, we
present the result of our study of the effects of ethylene gas and how it accelerates the fruit ripening
process.
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1. Introduction
Do you know how much fresh fruit is wasted every year in the EU? According to the FAO, Fruits and
vegetables, plus roots and tubers have the highest wastage rates of any food. On average more than
45% of the production is lost due to spoilage during various stages of the farm-to-table supply chain.
A substantial portion of the loss happens in households. As fresh fruits are often delicate, spoilage
happens fast. Not all fruits can be refrigerated in household type fridges. A lot of fresh fruit in
households are also kept on table-top counters, where temperature regulation cannot be attempted.
Is there a way to conserve fruit longer when using traditional cooling methods are not possible?
The purpose of our experiment is to test the effectiveness of existing methods against a new method
which has only been partially tested. The experiment has been conducted in a basic laboratory which
was the only one accessible to us in our school.
2. Materials and Methods
We decided to experiment with 5 kinds of fruits (not including the lemons we used for the 4th part of
the experiment). The goal was to leave each type of fruit in a typical environment for one week. Two
pieces of each fruit would be put in a freezer (at -22 degrees Celsius), two pieces in the fridge (at 3.6
degrees Celsius), two pieces outside in an open bag (at room temperature, 20 degrees Celsius), and
one piece outside in another open bag with a lemon. After leaving the fruit alone for one week, we let
it warm up to room temperature for about three hours and then cut them up in equal pieces. We then
gave it to a group of 22 students for a taste-test, together with a paper asking to rate each piece of
fruit as well as giving a description of the taste too. The results varied so we calculated the average for
each fruit, separating boys and girls. We put each fruit in four different environments to see what
would be the best method of preserving the fruits (each method should be practical so it can be
implemented into logistics and storage facilities). Our mentor helped us get permission to use the
school freezer and fridge so we could directly have access to them. The idea of using lemons in one of
the four environments was an idea we got from one of our parents.
3. Results
On average, fruits that stayed outside with a lemon in its vicinity scored higher on the taste tests than
the fruits that we kept in the fridge. The pears were the only fruit that scored much lower when it was
put together with lemons. The fruits that came out of the freezer were completely rotten and were
not edible whatsoever so we decided to leave them out of the test. The fruits which were kept outside
without a lemon scored in most cases below average. The apples were still reasonably tasty in every
test. The bananas tasted bad when put at room temperature without lemons, in the fridge they stayed
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reasonably good and with lemons they were even tasty according to most students. Overall, the fruits
kept outside with lemons scored best on every test (except pears), probably due to the release of
ethylene gas, the ones stored in the freezer were conserved reasonably well and the ones kept at room
temperature without lemons scored the worst in almost every case. This could potentially mean that
lemons are better for conserving fruit than cooling systems.
4. Discussion
Before we started the experiments we researched what caused fruits to ripen and what could enhance
those processes. We found that some fruits give off ethylene gas. This gas causes the ripening process
to speed up. This is one of the reasons that when you put fruits near bananas they ripe faster since
bananas produce a lot of ethylene gas.
According to our experiments and internet resources, colder environments do not disable the function
of the gas, but does slow down the ripening process. This results in the countering of the ethylene
gas’s function.
Lemons on the other hand emit a sort of acidic gas. This gas appears to exterminate the ethylene and
thereby eliminates the process accelerator. This may have major implications on the way logistics and
storage work in the field of fruit preservation.
5. Conclusion
Preserving fruits at room temperature in the vicinity of lemons is as effect as preserving fruits in a
cooled environment.
6. Acknowledgments
Mr. Karmarker, Mr. Leal, Mr. Sondern, Ms. Benta Leal, Ms. Laura Breuls, Ms. Megan Pennington, Ms.
Nadja Boulogne, Ms. Sophie Beekhuis, Ms. Naomi Dekempeneer, Ms. Selen Bayraktar, Ms. Sarah, Ms.
Laura Lembeye, Ms. Nynke Faber, Ms. Ambre Moedersheim, Ms. Lisa Poli, Ms. Alicia Bruggemans, Ms.
Ludivine Renard, Ms. Louisa Moerman, Ms. Desiree Molenaar, Ms. Elena Goovaerts, Mr. Mattia Lenne,
Mr. Victor Sanchez Martin, Mr. Daniel Sanchez Martin, Mr. Axel Smith, Mr. Roberto Perez Tobar, Mr.
Thomas Haijer.
7. References
Ethylene Control, About Ethylene, http://ethylenecontrol.com/aboutethylene/ .
Accessed on 21/Jan/2017 and 4/Feb/2017
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Dr. Gourmet, Is ethylene gas safe,
http://www.drgourmet.com/askdrgourmet/ethylenegas.shtml#.WJYQH7YrKXQ .
Accessed on 21/Jan/2017 and 4/Feb/2017
Post harvest, Ethylene: The Ripening Hormone, http://postharvest.tfrec.wsu.edu/pages/PC2000F .
Accessed on 21/Jan/2017 and 4/Feb/2017
Wikipedia, Ethylene, https://en.wikipedia.org/wiki/Ethylene .
Accessed on 21/Jan/2017 and 4/Feb/2017
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