Please use this template when preparing the IRS research report. The
requirements for each of the headings are spelt out in the same document.
Mrs Esther Koh / Mrs Koh Yong Yong
There is more to Oxidation than just the browning of fruits or the rusting of
metal. In fact, Oxidation isn’t as simple as we think it may be.
Oxidation, in our bodies, is quite a harmful process. It may bring about the
destruction of cells in our body and possibly cancer. A way to counteract
oxidation is by consuming antioxidants. Antioxidants are molecules that are able
to prevent the oxidation of other molecules.
Potential threats caused by Oxidation include certain diseases and
infections and possibly cancer. This makes oxidation a very scary and dangerous
process. People with weaker bodies may be more prone to these effects.
Oxidation, despite its downsides, is actually quite easy to deal with.
Antioxidants can be found in many things we eat. We can find antioxidants in
fruits, vegetables, eggs, vegetable oils, soy, coffee, and many more things that
we may consume daily.
Other than inside our bodies, oxidation can also occur in real life. If a slice
of fruit were to be oxidized, it may be spoiled. Other than that, oxidized fruits may
give the dish a bad image, bringing down restaurant ratings.
This is why antioxidants play a very important role in our daily lives, and
other people’s lives as well.
Sometimes, my mother will cut pieces of apples or pears and leave them
out on the table. Sometimes I do not have the time to eat the fruits (mostly
because of work) and I only go out after I finished my work. The fruits always turn
brown before I can even eat them. Looking at the brown apples and pears, I
suddenly lost interest in consuming them. At that time, I did not know it was
Although projects on oxidation have already been conducted numerous
times (many people in my class selected that topic for our science project, I did
not), I still had to test for myself. Taking advice from my teacher, I twisted the
experiment a little so that it had a little originality and fun.
All of that has inspired me to pick and finish this project and to start and
successfully complete the experiments. I wish to, through this project and
presentation, help people achieve the understanding of oxidation and how it
affects them, so that they will be able to how to prevent oxidation. Also, I hope
that through this project, I will be able to encourage myself to increase my intake
of antioxidants per day.
Oxidation, as we all know, is the interaction between oxygen molecules
and the different substances they may come into contact with. When those
substances interact, and at least one electron is lost, Oxidation is taking place.
Oxidation, in most cases is considered to be a harmful and dangerous
process. But in one case Oxidation isn’t really a bad thing, when it is used in the
making of super-durable aluminum.
The process of oxidation creates Free Radicals. Free Radicals are atoms,
molecules or ions with one or more unpaired electrons. In nature, electrons are
usually paired, but not in Free Radicals.
In their haste to get another electron, a Free Radical may attack nearby
chemical compounds and damage them. As a result, these chemical compounds
may stop functioning and in turn will make our bodies more prone to disease and
Free Radicals can give its odd electron to another molecule and can also
rob an electron from a nearby molecule. These actions can turn the affected
molecule into a Free Radical, which will then repeat the process.
To prevent oxidation in our bodies, we may consume antioxidants. To
physically observe antioxidants in action, we may apply them to a piece of apple
that is left out in the cold.
Antioxidants are molecules that can prevent the oxidation of other
molecules, by first being oxidized themselves, thus being able to terminate the
chain reactions by neutralizing the Free Radicals. They neutralize Free Radicals
by either providing the extra electron that they need or wrapping around them.
Antioxidants themselves can improve immune systems, better eye health
and can even help protect from cancer. Antioxidants can even help lower blood
pressure and help with the prevention of heart attacks and strokes.
There are many types of antioxidants.
Ascorbic acid, widely known as Vitamin C, commonly found in fresh
fruits and vegetables.
Polyphenol antioxidants, which are powerful antioxidants. Some
sources of Polyphenol antioxidants include tea, soy, fruit, olive oil,
cinnamon and grapes.
Tocopherols and Tocotrienols, or, Vitamin E, which can be found
inside vegetable oils.
Carotenoids, which can be found inside fruits, vegetables and eggs.
Ascorbic acid (Vitamin C)
Ascorbic acid, sometimes mistaken for Citric acid, is a sugar acid. It is an
antioxidant commonly consumed throughout the world, mostly because Ascorbic
acid can be found around us. Although Ascorbic acid may be found inside Citrus
Fruits alongside with Citric acid, Ascorbic acid is not Citric acid due to Citric acid
having one more oxygen molecule. Ascorbic acid is also the more versatile and
more essential amongst the two acids.
Ascorbic acid can be naturally found inside citrus fruits, broccoli, spinach
There are many uses for Ascorbic acid. Ascorbic acid is used as an
enhancer to bread dough as it promotes the growth of yeast. It is also used in
commercial food processing because of its antioxidant properties. Ascorbic acid
also plays an important role in our bodies.
By consuming Ascorbic acid’s nutrient form, L-Ascorbic acid (Vitamin C), it
helps to prevent oxidation in our bodies due to it being an antioxidant.
Low intakes of Ascorbic acid may lead to scurvy, inability to heal quickly
and easier bruising.
Polyphenol antioxidants are powerful antioxidants containing Polyphenol
substructures. A Polyphenol is a chemical compound belonging to a group of
chemical structures found in plants.
Polyphenol antioxidants can be found all around us too. Some good
sources of Polyphenol antioxidants include Green Tea and Grapes.
The most studied Polyphenols are Flavonoids. Flavonoids have medical
properties and can help with the prevention of cancers.
Grape Skin contains many Polyphenols and flavonoids, and thus is a good
antioxidant to consume. Other foodstuffs that contain Polyphenol antioxidants
range from Berries like Blackberries, blueberries and cranberries to soy and even
What kind of antioxidants will slow down the rate of Oxidation the best?
Can the antioxidants that can be applied to a cut piece of apple to slow
down the rate of oxidation be used on iron nails too, and achieve the same
Through this project, I hope to help people understand the importance of
antioxidants and how oxidation poses a threat to our daily lives, so that they will
know how to protect themselves from the process of oxidation, or how to do it
I also wish to encourage myself to eat more fruits daily, as doing this
project has inspired me to increase my intake of antioxidants per day.
I also hope to, at the same time, find out if antioxidants work on iron nails
too, and achieve the same results of the rate of oxidation being slowed down, or
share similarities with the experiment where I applied the antioxidants to the
pieces of apples.
I want to achieve better understanding of antioxidants, free radicals, and
the process of oxidation, so that in the near future, that information might become
a big help if I were to work on my career, or will be a big help to the society.
METHODS TO GATHER DATA
To gather the information needed, I conducted a classical experiment on
the oxidation of a few slices of apples in my home during the June Holidays in
2010. I also conducted another experiment to see whether antioxidants can slow
down the rate of rusting in the last week of September, 2010.
To start off, I had my mother cut a piece of apple into a few pieces. 4
pieces of apples were used for the experiment. Then, I applied the liquids Milk,
Green Tea and Lemon Juice to 3 of the apples. The last apple was left with
nothing applied to it for comparison. After applying the liquids, I put the pieces of
apple on a piece of cloth to prevent dripping. At every 1 hour interval, including
the start of the experiment, I would take a video of all the pieces of apples and
take photos of them. After the sixth video (5th hour), I stopped the experiment and
recorded my results on a table.
All of the ingredients and items used were fresh/new and not spoiled to
maximize my research findings. This is because if I used spoiled ingredients, my
results would not be as accurate as possible, as the ingredients have lost some
of their properties.
The experiment is recorded as a 2 MB video and a bunch of photos. The
video consists of 6 short clips in which we observe how brown the pieces of
apples were. The video includes texts where I typed in how brown the pieces of
apple appeared to be, from my eyes. The apples were given ratings based on
how brown they were. Examples of ratings include ‘No change’, ‘A little brown’,
and ‘Extremely Brown’.
The photos were also to observe how brown the pieces of apples were,
but from a different perspective.
Asides from the experiment, there are also other ways which I gathered
information. The first and simplest way involved me looking up the internet for
any relevant information that I could possibly have used in my experiment or my
presentation. The second way was asking around. By asking around, I gather
information on what other people think and know, allowing me to proceed with
my experiment and presentation much more easily. Some people I asked were
my science teacher and my father.
ANALYSIS & INTERPRETATION OF FINDINGS
Through my experiment, I have found the best liquids among the items I
chose that slowed down the rate of oxidation the most, was lemon juice. It was
followed by green tea and milk, and air was ranked last.
Below is a table showing the outcomes of the experiment. The results
have been given ratings based on how brown they looked like.
Intervals of 1 Hour 2 Hour 3 Hour 4 Hour 5 Hour
hours/Type Interval Interval Interval Interval Interval
None Very Very Very Extremely Extremely
Brown Brown Brown Brown Brown
Milk A little A little Brown Brown Brown
Green Tea No A little A little A little A little
Change brown brown brown brown
Lemon No No No No No
Juice Change Change Change change change
As you can see, lemon juice did a very good job in slowing down the rate
of oxidation. It scored 5 magnificent ‘No change’ ratings throughout the
experiment. Green tea did a remarkably good job as well but not as well as
lemon juice did, with 1 ‘No Change’ rating and 4 ‘A little brown’ ratings. Milk did
not do a good job as the apple was left with brown spots and a ‘Brown’ rating at
the end of the experiment. Air has lost straight away at the start of the
experiment with a ‘Very Brown’ rating after only 1 hour and an ‘Extremely Brown’
rating at the end of the experiment.
I found out that the lemon juice slowed down the rate of oxidation the best
because it contained a very high amount of Ascorbic acid and also contains
flavonoids. Green tea also did well as it contains powerful Polyphenol
antioxidants and flavonoids and a good amount of it too. Milk, which is not an
antioxidant, did badly at slowing down the rate of oxidation. And lastly, air, which
is obviously the worst, is of course ranked last, because it did not provide any
protection to the apple at all.
Through this experiment, I can conclude that foodstuffs with a higher
amount of antioxidants will do better reducing the rate of oxidation, mainly the
lemon and green tea. This is because a higher amount of antioxidants will
provide more protection from oxidation, thus slowing down the rate of oxidation
far more. Also, non-antioxidants will not able to reduce the rate of oxidation well.
But the milk didn’t go to waste – I found out that the layer of milk prevented a
small amount of air from reaching the surface of the apple where the oxidation
takes place, slowing down the rate of oxidation by a tiny bit.
With this information, people will be able to understand why some
foodstuffs work better at slowing down the rate of oxidation than others, and thus
they will be able to pick the antioxidants they want to consume more carefully
and cautiously while also preserving their food with the antioxidants.
One limitation that hindered me from reaching my goal is that I had to
decide on the suitable liquids to use for the experiment. Not only did I have to
consider the cost of the items but I also had to consider whether it was currently
available in my home – I cannot just take any liquid I can find that might be
suitable for the experiment from my refrigerator. But during the experiment, I
decided on the liquids that I was going to use and they were all affordable and
I also had to pick my items carefully, so as to not upset my friend, who is
also doing an experimental project, as one of my ingredients is the same as his.
Although our projects and experiments have some similarities, I had to take Citric
acid because I knew it will do well in the experiment.
For the second experiment, a big obstacle in the path was time. Rusting
naturally takes a long time and due to my tight schedule in semester 2, I found
very little time to conduct the experiment. This made me stressful as I haven’t
fully completed my IRS Project yet. Also, I had to find a time to ask my science
teacher how exactly do iron nails rust, as I did not have sufficient knowledge on
rusting at that time.
After the experiment, I concluded that foodstuffs with a high concentration
of antioxidants will do well slowing down the rate of oxidation, and therefore be a
suitable antioxidant for consumption.
Also, Antioxidants that work well in the body is sure to work well on a
piece of apple.
Furthermore, I found out that even non-antioxidants can slow down the
rate of oxidation by a tiny bit, and I can conclude that most liquids can be used to
slow down the rate of oxidation, but not all will do that well.
Once again, antioxidants prove to play an important role in our daily lives,
by showing themselves off on a slice of apple.
Antioxidant (Last updated: 22nd September 2010). Retrieved September 24, 2010,
Antioxidants – all you need to know (Last updated: NIL). Retrieved September 24,
Are Citric acid and Ascorbic acid twins? (Last updated: NIL). Retrieved
September 25, 2010, from
Citric acid (Last updated: 16th September 2010). Retrieved September 24, 2010,
Flavonoid (Last updated: 21st September 2010). Retrieved September 24, 2010,
How Antioxidants Work (Last updated: NIL). Retrieved September 24, 2010, from
Polyphenol Antioxidant (Last updated: 11th September 2010). Retrieved
September 24, 2010, from
Radical (Chemistry) (Last updated: 22nd September 2010). Retrieved September
24, 2010, from
Vitamin C (Last updated: 23rd September 2010). Retrieved September 25, 2010,
What are Flavonoids? (Last updated: 8th September 2010). Retrieved September
24, 2010, from
What is Ascorbic acid? (Last updated: 21st September 2010). Retrieved
September 25, 2010, from
What is Oxidation? (Last updated: 22nd September 2010). Retrieved September
24, 2010, from
What is Rust? (Last updated: 31st August 2010). Retrieved 24 September, 2010,
Why did my mozzarella cheese start turning yellow? (Last updated: NIL).
Retrieved September 25, 2010, from
Why do newspapers turn yellow over time? (Last updated: NIL). Retrieved
September 24, 2010, from
COMPONENTS OF THE RESEARCH REPORT
Your introduction should include the following:
o Provide the reader with an understanding of the current situation. The information
presented should also help reader understand why you are doing this research.
o Include any explanation of technical terms the reader needs to understand.
o State your research question
o Specify the scope of your project, i.e., what you will achieve through this project
Methods to gather data
Provide precise details on how the research was conducted.
Provide a clear description of the characteristics of the sample you collected data from.
State the size of the sample
Describe the instrument (questionnaire, interview questions, observation form), how it was
Describe the steps you took to gather data, when the data was collected and where data
collection took place.
Analysis and interpretation of findings
Present a summary of your data and identify trends and patterns from the data. You can
consider using graphs and charts to present your data.
Discuss what the trends and patterns may mean for your research question. You may
want to cite relevant references to support your interpretation.
Tell the reader how your research has contributed to the body of knowledge in the area
Discuss the limitations in your research.
Form conclusions based on your findings.
Propose new directions for future research.
Prepare a list of references you used in your research. References should be presented in APA
format and sorted in alphabetical order
Attach any instrument, raw data and so on in the appendix.