apple lemon juice experiment

• Earth Science
• Physics & Engineering
• Science Kits
• Microscopes
• Science Curriculum and Kits
• About Home Science Tools

Science Projects > Chemistry Projects > Why Does Lemon Juice Preserve Apples?  

Why Does Lemon Juice Preserve Apples?

Why do apples turn brown?

See it happen, first, in the experiment below.

Then, find out how chemical reactions work to keep your apples (or pears) fresh even after they’ve been cut!

Lemon Juice on Apples

What you need:.

• An apple or pear
• Sharp knife
• Lemon juice
• Small bowl (big enough to fit half the apple or pear)
• Clock/timer
• Paper plates
• Pen and paper

What You Do:

1. Use your pen and paper to make two labels, one reading “control” and the other reading “lemon.”

2. Pour lemon juice so it completely covers the bottom of the bowl.

3.  With adult help, cut the apple in half from top to bottom.

4.  Take one apple half and place it cut-­side down into the bowl of lemon juice. Leave it for two minutes. The other apple half without lemon juice is your ‘control’ sample that lets you see what normally happens to a cut apple.

5.  Observe the color of both apple halves, then place them white ­part­ up on the plates, with the corresponding labels nearby.

6.  Observe the apples again at 10-­minute increments, up to 30 minutes. Note any color changes and/or differences in appearance.

7.  Look at the apples again periodically throughout the day. What do you find?

What Happened:

When an apple is cut open, an enzyme (proteins that cause chemical reactions) called polyphenol oxidase is released from the cells of the apple and reacts with the oxygen in the air. This reaction causes the fruit to turn brown, similar to rust forming on metal.

Almost all plants contain polyphenol oxidase. It’s believed plants use it for defense. When a plant is damaged, the browning of the affected area may discourage animals and insects from eating it. It may also work to heal the plant. The browning creates an antibacterial effect, limiting the spread of destructive germs.

Lemon juice, however, acts a preservative . Why? Because it’s full of ascorbic acid (an isolate of Vitamin C) and has a low (acidic) pH level.

Ascorbic acid reacts with oxygen before it reacts with polyphenol oxidase. Even when the ascorbic acid is used, the pH of the lemon juice prevents browning. That’s because polyphenol oxidase works best in the 5 to 7 range on the pH scale. Lemon juice’s pH level is about 2, which keeps the polyphenol oxidase inactive.

More food preservation options

In addition to lemon juice, lime juice and cranberry juice also have a pH below 3.0. Concord grape juice and grapefruit juice also have a low pH (not quite as low as the others), but will help delay the browning process. You may want to try several of these juices and find a tasty to way to serve sliced apples and pears in the process!

To learn more about acids, bases, and pH, check out this science lesson .

More Chemistry Projects:

• Acid Base Reactions & pH Experiments
• Starch Test for Plants
• Baked Alaska
• Green Eggs and Ham

Welcome! Read other Chemistry articles or explore the rest of the Resource Center, which consists of hundreds of free science articles!

Shop for Chemistry Supplies!

Home Science tools offers a wide variety of Chemistry products and kits. Find affordable beakers, test tubes, chemicals, kits, and everything else you need for lab experiments.

Related Articles

Science Project Name Suggestions

Science Project Name Suggestions Thinking of a name for science fair projects for 7th graders or science fair projects for 8th graders is all part of the fun. Your kid’s sense of creativity will be challenged, and the unique name they come up with can boost their...

Science Fair Projects for 8th Graders

Science Fair Projects for 8th Graders As kids reach the 8th grade, their exposure to science goes up a notch. Equipped with basic knowledge, they can begin to explore more complicated concepts and satisfy their curiosity for deeper answers to the 'whys' and 'hows' of...

Science Fair Projects for 7th Graders

Science Fair Projects for 7th Graders​​ Science fair projects for 7th graders are a step up in complexity. Because 7th graders have a better grasp of science concepts, they’re expected to practice the scientific method in the way they approach their experiments–which...

Home Science Experiments for Preschoolers

Home Science Experiments for Preschoolers Home science experiments for preschoolers are a great way to pique your child’s curiosity, teach them valuable knowledge, and allow them to have some fun in the comfort of their own home. There are plenty of activities your...

Easy Science Fair Projects for Kids

Easy Science Fair Projects for Kids Science fairs are a long-standing tradition that provide kids with the opportunity to better understand practical concepts in fun and innovative ways. The great thing about the experiments presented at these events is that they...

JOIN OUR COMMUNITY

Get project ideas and special offers delivered to your inbox.

Apple Oxidation Science Experiment [Free Worksheet]

Learn what keeps apples from browning in this apple oxidation science experiment. Put apple slices in different solutions to find out which one is the best at preventing the apples from turning brown.

Why do apples turn brown? I bet your curious child has asked you that at one point or another. And perhaps he also challenged with a follow-up question – how do you prevent the apple from turning brown?

In this apple oxidation experiment, we are going to explore the chemical reaction that turns the apple brown. We will also test to see whether or not salt, vinegar, and other liquids keep apples from browning.

This is a great experiment to guide your kid through the scientific method of making an observation, asking a question, forming a hypothesis, designing an experiment, analyzing the data, and forming a conclusion.

The Scientific Method

Before we start the experiment, walk your child through the scientific method. 

Observation: The apple turns brown when you slice it open and leave it out.

Question: What will keep the apple from turning brown?

Hypothesis: Dipping the apple slices in a liquid will slow the browning process. Have your child predict which liquid will work the best and record it on the free apple oxidation experiment worksheet.

Now, let’s get to the experiment that will test the apple browning experiment hypothesis!

How to Set Up the Apple Oxidation Experiment

• Apple slices
• Diluted lemon juice
• Baking soda water
• Small containers
• Paper and pen for labeling
• Apple oxidation experiment free worksheet (download directions at the bottom of the post)

Directions:

1. Cut out small pieces of paper and write the name of the liquids you are going to test. One of them should be “air” for your control variable.

Having a control variable is necessary so that you can compare it to the other apples that have been submerged in various liquids.

2. Pour the other liquids into separate containers. 

3. Place the labels next to the corresponding containers. You don’t want to wait to do this and forget what the liquids are later. 

4. Place an apple slice in each container so that it’s submerged in the liquid. 

5. Wait a few minutes and take out the apple slices.

6. Place the apple slices on a plate and put the corresponding labels next to them.

7. Wait an hour and check on the apples. Discuss the progress of the oxidation.

8. Wait a couple more hours and check on the apples. Discuss any new observations.

9. Leave your apple slices for a total of 5 hours.

Check how brown the apple slices are and record observations on the free printable apple experiment worksheet. Your child can draw the oxidized apple slices in the space provided on the worksheet.

10. Which apple slice browned the fastest? Slowest? Did any of them turn brown really fast but then stayed the same color by the end of 5 hours? Or did any of them turn brown slowly and ended up the darkest brown by the end of the experiment?

You can also lightly squish the apple slices to feel the difference in texture. The apple slice in salt water felt like a sponge. The lemon juice made the apple mushy. And last but not least, the apple slice in milk is rock hard. So interesting!

When it comes to preventing an apple slice from browning, the winner is salt water! The lemon juice was a close second. Interestingly, vinegar seemed to have accelerated the browning process instead of slowing it down. 

To understand the results, let’s explore the science behind oxidation.

Science Behind Why Apples Turn Brown

Apples contain an enzyme called polyphenol oxidase (PPO). When you slice open an apple, the PPO reacts with the oxygen in the air and enzymatic browning occurs. The chemical reaction between the PPO and oxygen produces melanin, which is what gives the apple flesh the brown color.    

You can slow down oxidation by not allowing oxygen to react with the PPO in the fruit.

Since lemon juice worked so well, we at first thought acidic liquids, or liquids with a low pH level, would prevent the apple from browning. However, vinegar has a low pH level as well and it seemed to have accelerated the browning. So either we made an error in the experiment, or something else is at play here.

Lemon juice contains ascorbic acid or Vitamin C. Ascorbic acid will react with the oxygen before the oxygen reacts with the enzyme in the apple. Therefore, ascorbic acid will prevent the apple from browning until all the acid is used up. Vinegar does not have ascorbic acid, and therefore it did not work.

It is inconclusive why vinegar seemed to have sped up the browning. Vinegar is essentially acetic acid and water. Perhaps we need to dilute the vinegar with water? Is pure white vinegar too strong and started deteriorating the apple flesh? That’s an experiment for another day.

As for baking soda and milk, they are on the other end of the pH spectrum since they are bases.

Interestingly, milk did fairly well in preventing the apple from oxidizing. A future experiment can be designed to see if the fat content in the milk matters when it comes to blocking oxygen from reacting with the enzymes in the apple. 

Baking soda, however, made the apple brown faster. Alkaline (high pH level) liquids contain higher amounts of oxygen. Therefore, covering the apple with baking soda solution actually brought more oxygen to the surface of the apple, accelerating the browning.

Salt water prevented the oxidation of the apple slice because it surrounded the apple cells with a saltier environment than the inside of the cells. As a result, water moves outside of the cells through osmosis in an attempt to equalize the concentration of salt and water inside and outside of the cell.

The water and salt on the surface of the apple slice interfere with oxygen reaching the fruit’s surface and therefore slowing down oxidation.

Final Words on the Apple Oxidation Experiment

There seem to be many ways to prevent apples from browning. Salt water seems to be the best solution, but you would need to wash the salt off the apple afterward if you don’t want the salty taste.

Otherwise, lemon juice works well, but it is more expensive to use lemon juice than salt. And your apple might taste a little zesty and sour, but that might be a good thing!

As you can see, there are many more experiments you can perform after this one. For example, what other fruits turn brown when exposed to air? Will salt work as well on those fruits in preventing them from browning?

I hope your kid learned the basics of the scientific method and why apples brown from this experiment. Now we know what to do with our leftover apples!

For more fall kids activities, check out:

• Coffee Filter Fall Leaves Craft for Kids
• Apple Volcano Experiment
• Easy and Fun Paper Plate Apple Craft
• Easy 3D Paper Apple Craft for Kids

About The Author

5 thoughts on “apple oxidation science experiment [free worksheet]”.

There were some differences with mine. The apple piece in my fresh lemon water turned brown in 30 minutes. I gusse those lemon juice I used from fridage has not fresh or almost no antioxidation and less vatimin C. I’ll sample them to test its PH.

Definitely worth testing lemon juice from a bottle versus fresh lemon! Let me know if you come to a conclusion with the PH :). Thanks!

Thank you so much for this website I am doing this exact experiment for my CREST and this website has helped me understand so much and I really liked the explanation about the lemon juice as that was helpful to.

I am so glad that it’s helpful!

Some great ideas here. I am teaching a one hour weekly science lesson to a group of adults with intellectual disabilities. Its important to use experiments that they can visualize the process and results. Adding in something edible always wins the day!

Leave a Comment Cancel Reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Apple Oxidation Experiment

Introduction: Apple Oxidation Experiment

In case the video does not load, in order to watch paste the following link into your web browser: https://youtu.be/ldLxmkIWWZs

Step 1: Problem or Purpose

A problem that many people are facing is that their apples are browning quickly once they slice them into different slices and our experiment will conclude the best drink that keeps your apple slices fresh for the longest period.

What is the effect of different drinks on a slice of an apple?

Step 2: Hypothesis

If we add a slice of an apple in different drinks, the time taken for this slice to change color into brown will be different, because apples react differently with different types of drinks whether it was an acidic drink or a basic drink.

Step 3: Variables

Independent: the drinks we will add the apple slices into

Dependent: time taken for the slice to turn brown

Controlled: The freshness of each apple before we start the experiment, the type of apple (red apple), the temperature of the drinks and apples, amount of time to check on the apple slices.

Step 4: Background Research

What causes the apple to start bruising or turn brown is when it is exposed to oxygen, like when it is cut into slices, which causes apple oxidation. Some of the different materials and fluids used to prevent the browning of an apple are lemon juice, water, vinegar, and many more acidic drinks.

Step 5: Materials

1.4 containers

2.Diet 7up, Lemon juice, Low-fat Milk, Coke (1/4 cup each)

3.4 slices of apples

4.Camera/phone

6.Knife to cut apple

7.Measuring cup

Step 6: Procedure

1.Measure the drinks and pour about ¼ of the drinks into each container

2.Slice the apple

3.Place each slice of the apple into the container filled with the drink

4.Set a timer for 2 hours

5.Take notes of the apple with a picture of the slice every 30 minutes

6.After 2 hours have passed, take notes of the apple slice

7.Taste the apple slice to see which one changed the most taste and smell-wise.

8.Fill in the table with the left information and results

Step 7: Data

Step 8: Data 2

Step 9: Graph

Step 10: Data Analysis

From our experiment, we found out that different drinks will cause each apple slice to take a different amount of time to rot, and change color.

After 30 minutes, the apple slice in the diet 7up started turning a bit yellow (Brown Intensity: 20%), tastes like sweet lemon, smells like an apple with a bit of lemon. The apple slice in the lemon juice still looks the same (a white pale color) (Brown Intensity: 10%), tastes like a normal apple, smells like a normal apple. The apple slice in the milk was completely pale white (Brown Intensity: 10%), It tasted like an apple and there was no taste or smell of milk. The apple in the coke started turning brown (Brown Intensity: 30%), it did not taste like an apple but a strong flavor of coke, it smelled like coke and you can hardly smell the apple.

After 60 minutes, the apple slice in the diet 7up became a little more beige looking, (Brown Intensity: 40%), tastes like sweet lemon with a bit of fizz coming from the carbonated soft drink, smells more like a sweet lemon. The apple slice in the lemon juice has barely turned yellow (Brown Intensity: 20%), smells a little bit like lemon, has a hint of sourness. The apple slice in the milk was still completely white (Brown Intensity: 10%), tasted a bit like milk but mostly like an apple, you can hardly smell the milk. For the apple in the coke, it started turning brown (Brown Intensity: 50%), the apple took the taste of the coke and the taste got stronger, it started to smell like coke.

After 90 minutes, the apple slice in the diet 7up started turning a little brown (Brown Intensity: 43%), tastes very soft, also like lemonade with apple, smells a little like 7up and lemons. The apple slice in the lemon juice has started turning yellow (Brown Intensity: 35%), tastes very sour and lemony, smells a lot more like a lemon. The apple in the milk, was still white (Brown Intensity: 10%), the slice slightly tasted like milk but more like apples, it smelled like a bit of milk with apple juice. The apple in the coke’s color was dark from the amount of coke it absorbed (Brown Intensity: 70%), the taste of the coke is extremely clear and you can barely taste the apple, it smelled like coke and a rotten apple.

After 120 minutes, the apple slice in the diet 7up is a light brown (Brown Intensity: 45%), the apple slice is very soft and sweet and took the taste of the diet 7up, smells a lot like 7up and lemons. The apple slice in the lemon juice apple is still the same shade of yellow and has not darkened much (Brown Intensity: 40%), tastes a lot sourer, smells like lemons or lemon juice. The apple slice in the milk’s color was white and did not change at all (Brown Intensity: 10%), it tasted just like an apple with a little stronger taste of milk, it smelled like an apple mixed with milk.

Step 11: Data Analyisis 2

A few mistakes someone can make while conducting this experiment are: using a rotten apple while starting this experiment, using a different colored apple for every drink (when the controlled variable is using the same type of apple), placing the apple and its drink in different weather climates, not putting enough of the drink so it can cover the apple to be able to see some results, etc.

A few ways I can make my experiment better: use apples grown in different locations and places, use red and green apples to see the difference between them, keeping the apple slice in the drink in the fridge or at a hotter temperature to see the difference, etc.

1. This experiment is a solution to a big problem many people face, which is having their apples rot quickly.

2. This experiment was a successful experiment since we ended up with suitable results that can help others.

3. This experiment was done in real life and not digitally so we are sure that the results we ended up with are realistic and true.

Weaknesses:

1. A weakness is that the apples may have shown results if we kept them in the drinks for a longer amount of time.

2. The results may not be as accurate, because there are two different experiments placed in different cities, there is a chance that the weather and climate have an effect on the results of each experiment.

3. Putting an apple slice in a liquid may not be the best solution to keep your apples the freshest since it may not be suitable for kids in school or people transporting from a place to another, since they may not have all the materials and supplies needed.

Step 12: Conclusion

In our experiment, we tested the effect of different drinks on the rotting of an apple. Our hypothesis was correct since the apples were differently affected by the drink, they were put in. Our variables were: Independent, the type of drink, Dependent: the freshness of an apple. Controlled: the type of apple (red apple), the freshness of the apple when we began the experiment, the temperature of the experiment (room temperature). In conclusion, the lemon and the milk did the best job in this case, however, the apple slice that was put in the lemon eventually tasted and smelled only like a lemon. Therefore, milk is our suggested drink for people to use in order to keep the apples fresh since it made the apple stay the freshest and smelled and tasted more like an apple whereas the apple slices in the other drinks took the taste of the drinks and rotted quicker. In addition, milk will preserve the apple from getting brown because it's a basic liquid.

Step 13: Application

Our experiment is important because there are many people who enjoy only a piece of their apple but do not want to complete the whole thing. But the only problem is that when oxygen meets the apple, the apple starts to brown. And we were curious to find a way to avoid this from happening. So, we conducted an experiment, to find out which drink does the best job to keep the apple slice the freshest. Yes, this experiment can be applied with practice to do it correctly without making any mistakes in order to keep your apple slices fresh. After this experiment, we learned that milk and acidic drinks are the best drinks to keep your apple from browning. In addition, milk is the least drink that the apple took the drinks taste and smell.

Step 14: Evaluation

• Dima: during this project, I have represented a few of the ATL skills. Some are; researching skills, communication skills, thinking skills, self-management skills. I have shown research skills because once we started using different applications such as Instructables, I researched and learned how to properly use it to make sure I submit my assignments properly, as well as, at the beginning of the project we were asked to research our problem, and there I have collected a lot of information online. I have shown communication skills , because, throughout my work in a group, I made sure to stay in contact with my group members to see if I should help them with anything, also to get to know their ideas and opinions about what we are doing. I have also shown thinking skills because in the science fair I thought creatively about unique and different ways to complete my tasks. In addition, when I faced a problem I made sure to think about how I am going to solve it. Lastly, I have shown self-management skills since I submit all my tasks on time and I complete them correctly and the way I was asked to. I depended on myself and I was responsible throughout this project.

Allya: research skills, I feel like we used research skills because we researched about our experiment at the beginning to know what the experiment is about. Social skills, I feel like we used social skills because I and my teammates were communicating together during school hours and after school. Self-management, there was some work that I had to do individually so I depended on myself and I did the work myself me and my group collaborated together. Thinking skills, my group and I thought creatively while making the experiment during the hypothesis and the rest of the steps.

Sadeem: Social skills, I used my social skills to communicate with my group members. Self Management Skills, I used my time wisely and tried to stay free in case the group members needed me. Thinking skills, I used thinking skills to find some solutions to our problems and to find answers to my questions. Research skills, I researched why lemon juice made the apple turn out how it is, and in the background research step, I also used my researching skills in order to find answers to my questions.

Step 15: Resources

Source #1: How to keep apples from Browning? Here are 6 tricks we love. (2020, June 12). Retrieved from https://www.purewow.com/food/how-to-keep-apples-f...

Source #2: Why do apples turn brown? (2021, January 22). Retrieved from https://miniyummers.com/why-do-apples-turn-brown/...

Source #3: Prakash, S. (2019, September 24). The easiest ways to keep your apples from Browning. Retrieved from https://miniyummers.com/why-do-apples-turn-brown/...

Optional Promo Message

The Apple Mystery: A Fun Oxidation Experiment for Kids

Have you ever wondered why apples turn brown after you slice them? With this fun experiment, you can become a detective and crack the case!  

Materials: 

• Sharp knife (with adult supervision)  
• Cutting board  
• 5 small bowls or containers  
• Lemon juice  
• Salt water (mix 1 teaspoon of salt with 1 cup of water)  
• Baking soda water (mix 1 teaspoon of baking soda with 1 cup of water)  
• Pen and paper  

Let’s Experiment! 

• Prepare your apple slices: Wash and dry the apple. Cut it in half and then into thin slices. Try to make the slices as even as possible.  
• Label your bowls: Write the names of each liquid on separate pieces of paper and attach them to the bowls. You should have bowls labeled “lemon juice,” “vinegar,” “salt water,” “baking soda water,” and “water” (this is your control group).  
• Dip and observe: Place one apple slice in each bowl. Make sure the slices are completely submerged in the liquids.  
• Wait and watch: Set a timer for 30 minutes and observe the apple slices. Do they all start to brown at the same rate? The scientific term for the browning process is oxidation. Are some liquids more effective at preventing browning than others?  
• Record your results: After 30 minutes, take out the apple slices and compare them. How brown are they? Write down your observations in a chart or table.  
• Analyze the results: Which liquid did the best job of preventing browning? Which liquid had the least effect? Can you explain why?  

Explanation: 

When the apple flesh is exposed to air, the enzymes in the apple react with oxygen in the air, causing the browning. Lemon juice, vinegar, and salt water are acidic, which slows down the enzyme activity/ oxidation. Baking soda water is alkaline, which can speed up the browning process.  

Bonus challenge: Try the experiment with different types of apples and see if the results are the same. You can also try different liquids, like soda or honey water, to see how they affect browning.

Be the First to Know

Sign up to receive exclusive content and offers from Blue Marble.

• Privacy Policy
• Terms & Conditions
• National Geographic

Learning Galaxy

• Food for thought
• Activity Lab
• Product Zone
• Parenting Hacks

© 2023 Blue Marble ™ 

STEM Little Explorers

Knowing through exploring.

Home » Articles » STEM » STEM Science » Apple Oxidation Experiment

Apple Oxidation Experiment

You probably heard the word “antioxidant” in some health-related articles or commercials. but do you know what antioxidants are and how they work you will find out today with this simple apple science experiment, article contents.

1. What is Oxidation? 2. What are the Antioxidants? 3. The science behind the Apple Oxidation Activity 4. Materials needed for an Apple Oxidation Experiment with Lemon Acid 5. Instruction for Apple Oxidation Experiment 6. What Will You Learn And Develop By Doing this Apple Experiment

What is Oxidation?

In simple terms, oxidation is a loss of electrons in an element or a compound in contact with the oxygen in the air. The opposite process is called reduction. Reduction is the process where a compound or an element gains electrons in the contact with oxygen.

The most well-known example of oxidation is when iron combines with oxygen to form iron oxide or rust . In these situations, we say that iron has oxidized into rust.

After the discovery of electrons, scientists concluded that oxidation and reduction are happening at the same time. That process is called Redox reaction or Oxidation-reduction.

Some elements, such as Sodium, Magnesium, and Iron lose electrons more easily than the others – we say they are easily oxidized . On the other hand, there are elements that hold their electrons more tightly, like Nitrogen and Chlorine – they are hard to oxidize .

Interestingly, oxidation doesn’t necessarily involve oxygen! Oxygen was the first discovered oxidant so the name stayed until today. There is another oxidation definition that includes hydrogen . Here, oxidation is the loss of hydrogen, while reduction is the gain of hydrogen. This is the opposite of the oxygen definition, so it may be confusing. That’s why it is good to be aware of this alternative definition of oxidation.

What are the Antioxidants?

Antioxidants are the molecules that prevent oxidation in other molecules . Why is that important? Most life on the Earth requires oxygen for its survival. However, oxidation in our body can lead to the production of free radicals which may damage our cells.

If your body has high levels of free radicals, it can cause harm. Free radicals are linked to a variety of diseases, including diabetes, heart disease, and cancer. But they are mostly kept in check by our body’s antioxidant defenses.

Antioxidants are slowing down that process of oxidation – in theory, they could slow down the aging process and prevent the development of certain diseases. The best-known antioxidants in the human body are vitamins C and E and can be found in food, especially plant-based foods like fruit and vegetable. Lemon is especially rich in vitamin C because of the lemon acid. Lemon acid (just like all other acids) has lower pH values and that is why they slow down reactions with oxygen.

But next to being good for our bodies, antioxidants are used as food preservatives too! In the food preservation process, antioxidants are compounds that delay or prevent the deterioration of foods by oxidative mechanisms. It involves the addition of an oxygen atom or the removal of a hydrogen atom from the different chemical molecules found in food.

The science behind the Apple Oxidation Activity

Why is the apple quickly turning brown when peeled off or sliced? Apple contains a peel or shell that protects the inside of an apple. When the inner part of the apple is exposed to air, browning in apples occurs. That browning process is called enzymatic browning or oxidation reaction .

That’s because the oxygen-reactive enzyme is found under the surface (skin) layer. These enzymes are called phenols and they are found in the cells of the apple. The brown color of the skin is caused by the phenols being transformed into melanin . The phenolase enzymes need to be protected in order to stop the reaction. And that can be achieved by using heat or acid.

Citric acid from the lemon serves as an antioxidant in our experiment. All acids slow down the oxidation process because of their low pH. Oxygen will first react with acid and only when all acid has been depleted will it react with the apple enzymes. Then we will see an apple turning brown.

Materials needed for an Apple Oxidation Experiment with Lemon Acid

• Apple. One apple will be enough. The fresher apple will make the experiment more clear but any apple will suffice. Just make sure you are able to make at least 2 apple slices.
• Lemon. One lemon or even one slice of lemon will be enough. We just need to apply citric acid to one slice of the apple, and for that, we just need a small amount of lemon acid.
• Cup or bowl. Cup will help us to squeeze lemon in it so we can apply lemon acid more easily to the apple. But it’s entirely optional.
• Brush. As with the cup, the brush can help us to apply lemon acid to the apple slice more precisely for better experiment effects. But we can even soak the apple in acid or apply in any other way so the brush is also optional. 
• Kitchen knife. To slice the apple. It shouldn’t be a problem to get a kitchen knife so we can cut 2, same-sized apple slices for the best comparison of experiment results.

Instruction for Apple Oxidation Experiment

For video instruction on how to do this experiment, watch the “how-to” video at the beginning of an article or continue reading for step-by-step instructions.

1. Cut an apple in half, so you have 2 equal apple pieces.

2. Take the lemon you have prepared and squeeze it into a cup . Or you can directly squeeze the lemon juice on one apple slice if you want to speed up the process.

3. Take a brush, dip it into the lemon juice , and spread it over one apple slice . This will be our experiment slice where we try to prevent the oxidation process. Don’t apply anything to another slice since. We will see what happens to the apple if we don’t apply any food preservatives to it.

4. Leave your 2 apple slices at room temperature for a couple of hours. You can check your apple slices every hour to see if there is any difference. You should notice the differences between the 2 slices already after one hour.

5. Check the state of your apple halves after 1, 2, and 3 hours and talk with your child about the observed effects.

What Will You Learn And Develop By Doing this Apple Experiment

• Formulating scientific hypotheses,
• Planning and conducting a scientific experiment,
• Observing and tracking results,
• Enhancing the logical thinking skills,
• Learning about chemical processes, oxidation, antioxidants, and food preservatives.

If you enjoyed this experiment and would like to do more experiments with simple ingredients, check out these great activities:

• If you enjoyed the Apple oxidation experiment, you will love the Gummy bear osmosis experiment where you will learn about osmosis using tasty gummy bears.
• Learn How to make sugar crystals , and learn about crystallization while making a great homemade treat.
• Learn How to make plastic from milk and vinegar , and create your own amazing plastic from plain milk. With some molds, you can be your own toymaker!
• And for another kitchen experiment, be sure to try a simple Orange density experiment and learn about buoyancy.

Happy science learning and don’t forget about the most important thing – having fun!

If you’re searching for some great STEM Activities for Kids and Child development tips, you’re in the right place! Check the Categories below to find the right activity for you.

STEM Science

Videos, guides and explanations about STEM Science in a step-by-step way with materials you probably already have at your home. Find new Science ideas.

STEM Technology

Videos, guides and explanations about STEM Technology in a step-by-step way with materials you probably already have at your home. Find new Technology ideas.

STEM Engineering

Videos, guides and explanations about STEM Engineering in a step-by-step way with materials you probably already have at your home. New Engineering ideas!

Videos, guides and explanations about STEM Math in a step-by-step way with materials you probably already have at your home. Find new Mathematics ideas.

Find out all about development psychology topics that you always wanted to know. Here are articles from child psychology and development psychology overall.

First year of Child’s Life

Following a Child’s development every month from its birth. Personal experiences and tips on how to cope with challenges that you will face in parenting.

3 thoughts on “ Apple Oxidation Experiment ”

• Pingback: How to Make a Lava Lamp - STEM Little Explorers
• Pingback: Gummy Bears Osmosis Experiment - STEM Little Explorers
• Pingback: Learn about pressure with Can Crush Experiment - STEM Little Explorers

Leave a Reply Cancel reply

You must be logged in to post a comment.

Get Fresh news from STEM fields

I'm not interested in STEM

Science Fun

Apples And Lemons Kitchen Science Experiment

In this fun and easy kitchen science experiment for kids, we’re going to see if lemons can keep apples from turning brown.

Instructions:

• Cut the apple into four equal sized pieces.
• Put the pieces onto the plate.
• Now cut the lemon in half.
• Squeeze lemon juice onto two of the pieces of apple.
• Wait three hours and observe any differences between the two pieces of apple that have been covered in lemon juice and the two that have not been covered in lemon juice.

EXPLORE AWESOME SCIENCE EXPERIMENT VIDEOS!

How it Works:

When an apple is cut open, the enzymes in the apple become exposed to oxygen in the air, causing the oxidation process to begin. The longer the enzyme is exposed, the browner each slice will become. Lemon juice contains citric acid, and helps keeps the oxidation process from occurring.

Make This A Science Project:

Try different types of juices. Try timing different types of juices to determine which ones keep the apple from browning the longest. Try adding salt to the juice. 

EXPLORE TONS OF FUN AND EASY SCIENCE EXPERIMENTS!

SUBSCRIBE AND NEVER MISS A NEW SCIENCE FUN VIDEO!

previous experiment

Next experiment.

Ready to Make Circle Time Amazing?

Sign up for our FREE newsletter and receive my ebook 7 Circle Time Mistakes

Thanks for subscribing! Please check your email for further instructions.

Apple Science Experiment

We love delving into science experiments throughout the year. With fall fast approaching, it seemed like a great idea to try out some apple science!

What you need:

• Small containers
• Lemon juice
• Tonic water
• Apple Science Experiment Recording Sheet (optional)

This science experiment focused on how different liquids affect apples. My son and I used liquids we already had on hand, but I’m sure other liquids would work well, too.

Setting Up the Experiment

To set up the experiment, we set out five containers with a few apple pieces in each one. We labeled the five containers with the name of the liquids we were going to use.

Once everything was set up, we poured the appropriate liquids into each cup. We also set up a “control” cup of apple pieces without any liquid. Then it was time to wait and see  the chemical reaction.

The control apples had started to oxidize, as had the apples in soda. The apples in the vinegar had little brown spots, too. The apples in the water looked like they had oxidized a tiny bit in comparison to their original state, but not much.

(Oxidizing happens when the apples come in contact with the oxygen in the air and begin to react, turning brown.)

There is an enzyme in the apples, that when exposed to oxygen, turns the apple brown. Lemon juice, for example, keeps the apples from browning, because it slows down this enzyme. Keeping the apples submerged regardless, will help to cut off the oxygen supply to the apples.

Your little one might notice that all the apples in a liquid, turned less brown, than the control.

My son and I did this experiment together over the summer. He likes to help me “test” activities before I try them in my classroom. This activity would be perfect during center time, when I can engage with small groups.

Early Learning Concepts

This simple, fun apple science experiment touches on many early learning concepts. Below are a few:

• Counting – counting the apple pieces that go into each bowl
• Writing – children can help label each container
• Scientific process – ask a question, experiment, observe, and record
• Vocabulary – use different words to describe observations

BIO: Mary Catherine is mama to one and preschool teacher to many. She has over ten years’ experience in early childhood education, teaching kindergarten and pre-k. Mary Catherine writes about meaningful early learning at Fun-A-Day . You can also find her on Pinterest , Facebook , and Twitter . Be sure to pop over to her apple-themed activities and her apple Pinterest board for more ideas.

*The Apple Science Experiment Record Sheet is also available as a free printable on Fun-A-Day.

More Apple Themed Activities

Apple Print Number Line  (Pre-K Pages) Read the book  Ten Apples Up on Top  and create a life-size number line with apple prints.

Apple Hedgehogs: Fine Motor Activity  (Pre-K Pages) Use apple halves and toothpicks to create hedgehogs and develop fine motor skills.

Apple Counting Book  (Pre-K Pages) Make and count seeds on the numbered apples in this free printable book.

Apple Tree Alphabet Game  (Pre-K Pages) Identify letters on the tree and cover them with “apples” (pompoms); use a clothespin or tweezers to add fine motor practice.

Handprint and Fingerprint Apple Tree Art  (Pre-K Pages) Paint, trace, and cut to create an apple tree in this multi-step art exploration.

Apple Pizza Snack Activity  (Pre-K Pages) Make (and eat) your own apple “pizza” using this fun interactive snack activity.

Apple Tree Play Dough Activity  (Pre-K Pages) Explore trees and apples using play dough (and a free printable).

2 thoughts on “Apple Science Experiment”

Pingback: 30 Science Experiments You Can Do At Home -

Pingback: Get Outside & Connect: Visit an Apple Orchard - Rhythms of Play

Comments are closed.