the apple browning experiment

Apple Science Experiment: Prevent Browning

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My kids love eating apples, but they really don’t love it when they turn brown. We decided to try a fun apple science experiment so they could learn what keeps apples from browning. (See 200+ more STEM projects for kids)

We first talked about why apple brown and discussed the comparison with rusting (oxidation). It is a chemical reaction with the oxygen and an enzyme in the apples. This helped the kids understand why it happened.

How to Do the Apple Experiment:

To do this apple science experiment, you’ll just need a few items: an apple, a knife, a few bowls, and various edible liquids.

I already knew the answer to this apple oxidation experiment, but I didn’t want to let my kids know about it. I let them choose various substances and liquids from the kitchen to soak the apples in. I did make a suggestion of lemon juice, but let them choose the other things.

The kids chose vinegar, milk and baking soda . Another good one to try is salt water. Just to give them a comparison, I left one with nothing  on it (the control variable).  You could also use plain water as the variable.

We sliced the apples and put the slices into each substance to soak. Label them so you remember which one is which. We left the apple slices soaking for about an hour.

Let kids make their own hypothesis about which one will work best.  They were excited to see the results.  Their guesses were not correct…  Check out my Scientific Method printables to help you teach this!

While some liquids might work better than others, taste is important, as well. If you soaked apples in salt water, they would not taste nearly as good!

How to Keep Apples from Turning Brown

I then explained to them that lemon juice helps keep the apple from browning, because it is full of ascorbic acid (Vitamin C) and it has a low pH level.  Ascorbic acid works because oxygen will react with it before it will react with the enzymes in the apple.  Once the ascorbic acid gets used up, the oxygen will start reacting with the enzymes in the apple  (polyphenol oxidase) and browning will occur.  Did you know why apples turn brown?

DOWNLOAD the free printable apple browning experiment worksheet now!

Want more simple science experiments? Check out this big list of Simple Science Experiments for Kids !

Also, a little more on Oxidation with this Rust Experiment !

A Few More Apple Learning Ideas:

A magnetic science activity to go along with the book 10 Apples Up on Top

Ways to Play with an Apple Carton

Pi Day with Apple Pie

All About Apples- Great list of apple learning and play ideas!

Extend the Learning with Some Apple Books:

How do Apples Grow? by Betsy Maestro

Apples by Gail Gibbons

The Season’s of Arnold’s Apple Tree by Gail Gibbons

Apples, Apples Everywhere by Robin Koontz

Apple Farmer Annie by Monica Wellington

Apples, Apples, Apples by Nancy Elizabeth Wallace

Save Save Save Save Save Save

Former school teacher turned homeschool mom of 4 kids. Loves creating awesome hands-on creative learning ideas to make learning engaging and memorable for all kids!

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Always looking for more fun science experiments! Pinning this one!

I wonder what the variables are

the dependant variable is how much the apples browned and the independent variable is the liquid used

I hear you but then i still have a question, if you were to record in on a table or a graph for that matter, how would you measure how much it has browned? By sized? Because i am stuck now

This version of the experiment seems to generate a simple yes or no result as opposed to a measurable DV. If you need to quantify the dependent variable, perhaps try identifying quadrants on each apple slice and discussing the amount of browning as percentages? Or… maybe counting spots? I wonder if it might even be fruitful (pun intended) to look at the time it takes each liquid of independent variable to brown. No browning would be ‘n/a.’ You might even compare acidic (vinegar) vs. alkaline (baking soda).

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Great science experiment! Can’t wait to try it with my kids.

This is such a great idea! My children LoVe apples. Doing an experiment with them makes total sense! Thanks for sharing 😉

Thanks! Glad you like it! 🙂

A tiny bit of honey also prevents browning. Like a drizzle and then shake to coat. Doesn’t work as long as lemon juice but also isn’t as tart.

use salt water also can prevent apple becoming browning!

What is the Variables like control, independent, and dependent, causes of this project.

Definitely going to be doing this for our picnic theme! Great idea

I use apple juice to keep apple slices from turning brown. It will even reverse light browning.

I will be doing this experiment with my daughter soon. I have always soaked apples in pineapple juice to prevent browning, and look forward to seeing how it compares to lemon juice!

also you could use a temporary vacuum chamber by taking a plastic bag and putting the apple inside of it . put the bag in to a bucket of water with the bag partially opened. the water pressure on the bag will force the air out of the bag and temporarily vacuum seal the bag. hope this helps 🙂

can you please provide a list of procedures

What common core standard would go with this science experiment?

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Apple Browning Experiment

How do you keep apples from turning brown? Do all apples turn brown at the same rate? Let’s try to answer these burning apple science questions with an apple oxidation experiment that is pretty quick and easy to set up at home or in the classroom. Pair it with other fun apple science experiments!

Try This Apple Browning Experiment For Fall

Have you ever found a bad spot on an apple or opened a container in a lunch box filled with apple slices that were once pearly white and now look a bit on the used-up side. The bad spot is definitely not tasty, but the slightly browned apples aren’t all that bad!

Is it safe to eat brown apples? My son tasted the brown slices of his favorite apple, the honey crisp, and declared them still ok. Not all apples are similar in their rate of browning!

How do you keep apples from turning brown? Lemon juice is often suggested as a solution for keeping apples from turning brown. Does lemon juice really work and how does it stop or slow the browning process?

Let’s try a simple apple experiment and find out how to stop apples from browning!

Using The Scientific Method With Kids

The scientific method is a process or method of research. A problem is identified, information about the problem is gathered, a hypothesis or question is formulated from the information, and the hypothesis is tested with an experiment to prove or disprove its validity.

Sounds heavy! What in the world does that mean?!? It means you don’t need to try and solve the world’s biggest science questions! The scientific method is all about studying and learning things right around you.

As children develop practices that involve creating, gathering data evaluating, analyzing, and communicating, they can apply these critical thinking skills to any situation.

READ MORE:   The Scientific Method For Kids With Examples

Note:  The use of the   best Science and Engineering Practices   is also relevant to the topic of using the scientific method. Read more and see if it fits your science planning needs.

Helpful Science Resources To Get Your Started

Here are a few resources that will help you introduce science more effectively to your kiddos or students and feel confident yourself when presenting materials. You’ll find helpful free printables throughout.

• Best Science Practices (as it relates to the scientific method)
• Variables In Science
• Observation In Science
• Science Vocabulary
• 8 Science Books for Kids
• All About Scientists
• DIY Science Kits
• Science Tools for Kids

Set Up An Apple Browning Science Project

Science projects are an excellent tool for older kiddos to show what they know about science! Plus, they can be used in all sorts of environments including classrooms, homeschool, and groups.

Kids can take everything they have learned about using the scientific method , stating a hypothesis, choosing variables , making observations and analyzing and presenting data.

Want to turn this apple oxidation experiments into an awesome science fair project? Check out these helpful resources.

• Science Project Tips From A Teacher
• Science Fair Board Ideas
• Easy Science Fair Projects

Why Do Apples Turn Brown?

There’s great science behind the process of why an apple turns brown or why rotten spots are brown.

The simple science is that when an apple is damaged, or even cut into slices, the enzymes in the apple react with the oxygen in the air, which is a process called oxidation. The apple produces melanin to protect the apple which is the browning you see.

We watched this short video on Why do Apples Turn Brown?   which digs deeper into the exact science of polyphenol oxidase (PPO) enzymes. It’s a mouthful!

How Does Lemon Juice Stop Apples From Browning?

Lemon juice helps keep the apple from turning brown because it is full of ascorbic acid (Vitamin C) and it has a low (acidic) pH level. Learn more about the pH scale.

Ascorbic acid works because oxygen will react with it before it reacts with the polyphenol oxidase enzyme in the fruit. What else might prevent apples browning in a similar way?

Alternatives To Lemon Juice

We investigated whether lemon juice on apples stops them from turning brown in the experiment below. Why not extend the learning and compare different ways to prevent cut apples from browning!

You could also test…

• Ascorbic Acid Powder
• Plain Water

Get your printable apple experiment worksheet!

Apple Oxidation Experiment

This is a great experiment to set up using the scientific method for kids . Use our printable apple browning experiment worksheet below to record your observations.

The independent variable will be the type of apple, and the dependent variable will the amount of lemon juice you add to each apple. Can you think of any other dependent variables?

• Apples! (We used 5 varieties of apples since we had just completed our apple 5 senses science activity beforehand.)
• Lemon Juice (or real lemon)
• Paper Plates, Knife, Small Cups (optiona)
• Printable Journal Pages

STEP 1: Label the paper plates with the name of each type of apple you are using.

STEP 2: Then cut two wedges of the same size out of each apple.

STEP 3: Place one wedge in a small dish and the other on the plate alongside the rest of the whole apple.

STEP 4: Squeeze a little lemon juice over each slice in the dishes and mix to coat evenly. Dump out excess juice. Do this for each apple.

STEP 5: Now wait and be patient. Record your observations.

If you want, set out a timer to get an accurate measurement of the time it takes for each apple to turn brown. This way you can record results in number of minutes for drawing conclusions later.

Our Results

• Which apple turned first?
• Did they all turn equal shades of brown?
• Does the apple slice coated in lemon juice taste different than the plain apple slice?
• Does the brown apple slice really taste all that bad?
• Did the lemon juice really work?

BELOW WAS OUR QUICKEST TURNING AND DARKEST BROWN APPLE SLICE.

He went on to happily eat both slices of cut apple and found them tasty. Fall is a great time of year for exploring apples!

More Fun Apple Science Activities

• Learn about the parts of an apple .
• Use our printable life cycle of an apple worksheets to explore how an apple grows.
• Develop your observation skills with an apple 5 senses activity .
• Set up this awesome apple volcano experiment.
• Enjoy balancing apples for simple Fall physics.

Printable Preschool Apple Activities Pack

Get ready to explore this year with our growing Preschool STEM Bundle !

What’s Included:

There are 5 fun preschool themes to get you started. This is an ” I can explore” series!

• My 5 Senses
• All About Me
• Science and Scientist

Each unit contains approximately 15 activities, with instructions and templates  as needed. Hands-on activities are provided to keep it fun and exciting. This includes sensory bins, experiments, games, and more! Easy supplies keep it low cost, and book suggestions add the learning time. 

Or grab the Apple Preschool Pack on it’s own!

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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/...

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Activity – Slowing Apple Browning

By David A. Katz and Veronica I. Jaramillo

Safety Suggestions

• Ask an adult for permission to do the activity and for help when necessary.
• Read all directions and safety recommendations before starting the activity.
• Wear appropriate personal protective equipment (safety glasses, at a minimum), including during preparation and clean up.
• Tie back long hair and secure loose clothing, such as long sleeves and drawstrings.
• Do not eat or drink food when conducting this activity.
• Clean up and dispose of materials properly when you are finished with the activity.
• Thoroughly wash hands after conducting the activity.
• Do not eat or drink any of the materials used in this activity.

Disposal: All unused solutions can be poured down the drain with running water. All the apple pieces can be disposed of in the trash.

Introduction

Have you ever thrown away apple or avocado slices because they started turning brown? Many people find fruit slices with brown spots to be less appetizing. The browning can change the taste and texture of fruit, as well as how it looks. This browning is due to a chemical reaction with oxygen in the air, and it may be responsible for up to half of all food waste. If there were only a way to slow this chemical reaction down, it would prevent a lot of waste … and save a lot of money!

In this activity, you will test different ways of slowing down browning in fruit through chemistry. You’ll add different substances to apple slices to discover the most effective way to prevent the slices from turning brown.

• Cutting board
• Plastic knife
• ¼-cup (about 60 mL) measuring cup
• 6 paper plates
• 5 plastic cups
• Lemon juice
• Label 5 plastic cups with these titles: Lemon Juice, Vinegar, Water, Salt Solution, and Sugar Solution.
• Label 6 paper plates with these titles: Lemon Juice, Vinegar, Water, Salt Solution, Sugar Solution, and No Liquid.
• Add ¼ cup (60 mL) water to each of the 3 cups that are labeled Water, Salt Solution, and Sugar Solution.
• Make the solutions by adding 1 teaspoon (5 mL) of salt and 1 teaspoon of sugar to each labeled cup and stirring with a spoon to dissolve.
• Pour ¼ cup lemon juice into the cup labeled Lemon Juice.
• Pour ¼ cup vinegar into the cup labeled Vinegar.
• With the help of an adult, cut the apple into at least 6 uniform slices. Lay one slice on its side on each of the six labeled plates. Use a spoon to dip each of the apple slices into the matching labeled cup for 30 seconds, remove the slice, and then place it on its labeled plate. The apple slice on the plate labeled No Liquid, should not be dipped in any liquid.
• Check the apple slices at 10-minute intervals for up to one hour. Record your observations in the data table.

What did you observe?

Describe what the apple slices look like. Possible results could include no browning, slight browning, brown patches, halfway light brown, completely light brown, and completely dark brown.

How does it work?Look at your data, and compare the browning of your different apple samples to the control apple, which was the slice not dipped in any solution. Which apple browned the least? Which solution was best at slowing down the browning reaction?

An enzyme in apples speeds up the chemical reaction between the fruit tissue and oxygen in the air. When fruits or vegetables are peeled or cut, the enzymes in the plant tissue are exposed to the air. The oxygen in the air speeds up the conversion of some of the nutrients in the apple to a brown product. This browning can be prevented by making the enzyme stop working or slow down.

In your experiment, some of the treatments worked better than others to prevent browning. If they worked, it was because they interfered with the enzyme. Changes in acidity, saltiness, and oxygen content can all affect the enzyme action. Lemon juice and vinegar are quite acidic, and work by altering the pH of the solution. Salt can break up protein structure, which is what enzymes are made of. Sugar solutions can coat the surface of fruits, and prevent oxygen from getting to the surface. Review your results and decide which solution did the best job of slowing down the browning action of the fruit.

Just because something works to prevent browning doesn’t mean you want to use it on fruit you plan to eat. Which of the solutions would have the smallest effect on the flavor of your apple slices?

David A. Katz, Ph.D. is a Consultant of Chemistry Education in Wilmington, DE. Veronica I. Jaramillo, Ph.D. is the Department Chair of Physical Science at Pasadena City College in Pasadena, CA.

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Effect of Acids and Bases on the Browning of Apples

Everything You Need for This Simple Experiment

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Apples and other fruit will turn brown when they are cut and the enzyme contained in the fruit (tyrosinase) and other substances (iron-containing phenols) are exposed to oxygen in the air.

The purpose of this  chemistry laboratory exercise is to observe the effects of  acids and bases  on the rate of browning of apples when they are cut and the enzymes inside them are exposed to oxygen.

A possible hypothesis for this experiment would be:

Acidity (pH) of a surface treatment does not ​affect the rate of the enzymatic browning reaction of cut apples.

Gather Materials

The following materials are needed for this exercise:

• Five slices of apple (or pear, banana, potato, or peach)
• Five plastic cups (or other clear containers)
• Vinegar (or dilute acetic acid )
• Lemon juice
• Solution of baking soda ( sodium bicarbonate ) and water (you want to dissolve the baking soda. Make the solution by adding water to your baking soda until it dissolves.)
• Solution of milk of magnesia and water (ratio isn't particularly important - you could make a mixture of one part water one part milk of magnesia. You just want the milk of magnesia to flow more readily.)
• Graduated cylinder (or measuring cups)

Procedure - Day One

• Lemon Juice
• Baking Soda Solution
• Milk of Magnesia Solution
• Add a slice of apple to each cup.
• Pour 50 ml or 1/4 cup of a substance over the apple in its labeled cup. You may want to swirl the liquid around the cup to make sure the apple slice is completely coated.
• Make note of the appearance of the apple slices immediately following treatment.
• Set aside the apple slices for a day.

Procedure and Data - Day Two

• Observe the apple slices and record your observations. It may be helpful to make a table listing the apple slice treatment in one column and the appearance of the apples in the other column. Record whatever you observe, such as the extent of browning (e.g., white, lightly brown, very brown, pink), the texture of the apple (dry? slimy?), and any other characteristics (smooth, wrinkled, odor, etc.)
• If you can, you may want to take a photograph of your apple slices to support your observations and for future reference.
• You may dispose of your apples and cups once you have recorded the data.

What does your data mean? Do all of your apple slices look the same? Are some different from others?

If the slices look the same, this would indicate that the acidity of the treatment had no effect on the enzymatic browning reaction in the apples. On the other hand, if the apple slices look different from each other, this would indicate something in the coatings affected the reaction.

First, determine whether or not the chemicals in the coatings were capable of affecting the browning reaction .

Even if the reaction was affected, this does not necessarily mean the acidity of the coatings influenced the reaction. For example, if the lemon juice-treated apple was white and the vinegar-treated apple was brown (both treatments are acids), this would be a clue that something more than acidity affected browning.

However, if the acid-treated apples (vinegar, lemon juice) were more/less brown than the neutral apple (water) and/or the base-treated apples (baking soda, milk of magnesia), then your results may indicate acidity affected the browning reaction.

Conclusions

You want your hypothesis to be a null hypothesis or no-difference hypothesis because it is easier to test whether or not a treatment has an effect than it is to try to assess what that effect is.

Was the hypothesis supported or not? If the rate of browning was not the same for the apples and the rate of browning was different for the acid-treated apples compared with the base-treated apples, then this would indicate that the pH ( acidity, basicity ) of the treatment did affect the rate of the enzymatic browning reaction. In this case, the hypothesis is not supported.

If an effect was observed (results), draw a conclusion about the type of chemical (acid? base?) capable of inactivating the enzymatic reaction.

Additional Questions

Here are some additional questions you may wish to answer upon completing this exercise:

• Based on your results, what substances in each apple treatment affected the enzyme activity responsible for the browning of the apples? Which substances did not appear to affect the enzyme activity ?
• Vinegar and lemon juice contain acids. Baking soda and milk of magnesia are bases. Water is neutral, neither an acid nor a base. From these results, can you conclude whether acids, pH neutral substances, and/or bases were able to reduce the activity of this enzyme (tyrosinase)? Can you think of a reason why some chemicals affected the enzyme while others didn't?
• Enzymes speed the rate of chemical reactions. However, the reaction may still be able to proceed without the enzyme, just more slowly. Design an experiment to determine whether or not the apples in which the enzymes have been inactivated will still turn brown within 24 hours.
• Examples of Chemical Reactions in Everyday Life
• 5 Ways to Make Glue
• A Guide to Acid-Base Equilibrium Constants
• A to Z Chemistry Dictionary
• Why Do Apple Slices Turn Brown?
• Acid-Base Chemical Reaction
• Learn the pH of Common Chemicals
• How to Make Buttermilk
• Do You Know If Milk Is an Acid or a Base?
• How to Neutralize a Base With an Acid
• How to Make a Red Cabbage pH Indicator
• How to Make Non-Toxic Glue From Milk
• Fruit Ripening and Ethylene Experiment
• Acid & Base Science Fair Project Ideas
• 10 Facts About Acids and Bases
• What Is the Acidity or pH of Milk?

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Apple Science Experiment with Worksheets

Published: Aug 23, 2021 · Modified: Mar 26, 2024 by Julie

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Have you ever sliced an apple, only to find it has quickly turned brown? In this apple experiment, kids will observe how different liquids effect the process of apple browning.

Practicing science is fun and hands on with this classic science experiment!

• Science Concepts

If you are learning about science with your kids, simple science experiments are a fun way to practice the scientific method . One of the best ways to test out a hypothesis is through a hands on exploration.

This Post May Contain Affiliate Links. Please Read Our Disclosure Policy .

Why Do Apple Slices Turn Brown After being Cut?

Recommended age range, apple oxidation experiment worksheets, preparation, optional liquids, helpful hints, the science behind apple browning, concept of apple browning, more apple activities and project ideas, comparing different varieties of apples, storing in a plastic bag vs no bag, other browning fruits.

In this apple science experiment, kids will learn about the process of oxidation. Depending on the age of your kids, you can modify how much of this experiment they set up and run on their own.

A great activity to go along with this is to do an apple exploration with your kids to learn about the different parts of an apple.

If you are looking for ways to explore apples with your kids, check these additional apple activities for kids .

The great thing about experimenting with kids is that you can take a lesson and modify it to fit your needs.

If your child is practicing identifying variables and designing an experiment, they can be in charge of that part.

While for younger kids, you can provided a more guided approach.

When doing this with elementary aged kids, you can have them pick the liquids, help cut up the apples, and run the timer.

Younger kids can make observations, pour liquids, and drop the apple slices into the different containers.

Kids of all ages love having jobs, especially when running an experiment. Before you begin, decide who will be in charge of each task. Don't forget about clean up! Kids can be in charge of putting back supplies or washing containers.

Apple oxidation, commonly called browning, happens after an apple is sliced or damaged. Various liquids can be used to slow down apple browning. ( source )

If you are doing this apple experiment with young children that will be enough of an explanation. However, a description of the process along with vocab terms if doing this with older children can be found later on in the post.

More Autumn Activities: Painting with Apples and Fall Leaf Printables

• Middle School

If I was going off of the description above I would say, middle school aged kids. But honestly, young kids even preschoolers will enjoy this experiment.

What is great about this science experiment is that you can tailor it to fit your child's needs.

Remember, you do not need to explain all of the fancy scientific concepts that are found later on in the post.

Lab sheets are great for elementary and middle school aged kids. Young children can simply discuss the changes you see.

There is also a guided version of the worksheet available for download as well. This version has some of the parts filled out for your child.

Directions for how to access the downloadable free printable worksheets is found at the bottom of this post.

Before beginning this experiment you will want to gather a few supplies. First make sure you have apples! Depending on how many kids are doing this experiment will determine the amount of apples you need.

One apple is more than enough if you are doing it at your house with your kids.

If trying this out with a larger group, I would plan on having a few apples. I try to not be wasteful with food, so I sliced the apples very thinly.

Before doing the experiment with your kids, I would go over the directions, fill out the lab sheet, and talk about what you will be doing. Then begin the experiment with your kids.

Often times kids are so excited to get started that they miss out on practicing important science skills such as identifying variables and making a hypothesis.

Slicing the Apples

You will also need a safe way to cut the slices using either a knife or apple corer. I used a knife with a cutting board and cut the apples for my child.

Picking Out the Different Liquids

For this apple experiment, your kids will be testing out different solutions to see how well they prevent browning of the apple pieces.

Pick out the different liquid substances before beginning this science project. You will also need containers to hold the liquids, I used small glass Pyrex containers .

After the materials list below, I give you a few recommendations for liquids.

As you can see from the image above, I used salt water, apple cider vinegar, freshly squeezed orange and lemon juices, and plain water.

• 1 Container per Liquid
• 1 Lid per Liquid
• 1 Toothpick per Liquid
• 1 Knife or Apple Corer
• Cutting Board
• 4 or More Liquids
• Water (Control)
• Flat Work Surface
• Recording Sheet
• Optional: magnifying lens

All of these directions can be found on the downloadable lab sheet. Even if you do not use the sheet with your kids, it may be helpful to have printed directions.

• Gather supplies and pick out your liquids
• Set out one container per liquid on a table.
• In front of the container place a lid (this will hold the apple slice)
• Add labels in front of each lid with the name of the liquid or place the main container of the liquid behind the set up. You want to easily see which liquid was used for each slice.
• Add a small amount of each liquid into each of the containers. Enough liquid to coat the slice once it is placed in the liquid.
• Prepare your apple slices using a knife or apple corer. *As the adult, I cut the apples
• Add one apple slice into each of the liquids. Set the timer for 1 minute. Remove the apple slices from the liquids using a toothpick. Place slices onto the lids.
• Reset the timer for the next length of time then make your observation.
• Record observations for one minute, 10 minutes, 20 minutes, and 40 minutes.
• Compare your final results after 40 minutes to the control. Record which liquid prevented the apple slice from browning the most.
• Clean up the experiment. Then write your analysis and conclusion.

If you do not have lids available, parchment paper or plates can be used. I would not recommend placing wet apples directly onto a paper towel because the liquid can saturate the towel.

You can use more than four liquids, just make sure to plan one lid and glass container per liquid. Water will be the control which also needs a lid and container.

When I ran this experiment with my child, we used plain water as the control apple. However, I noticed the apple left out without being dipped into the water showed more signs of browning.

I recommend leaving a slice out on the table that never is dipped into a liquid. Kids can compare the results to that apple as well!

Now the fun part, the science behind why apples turn brown. Depending on the age of your child will determine how in depth you want to explain this process.

I broke up the vocab terms into simple and advanced.

However, you can do this fun science project without explaining all of the fancy science terms! I included them in case you want to go that route with your kids. Some kids love knowing the why behind what they are seeing.

Simple Vocab Terms

• apple or fruit
• guess or hypothesis
• observation

Advanced Vocab Terms

When apples turn brown, they are undergoing a chemical change as the slices are exposed to air.

If you happen to have older kids, they could also do this experiment along with researching the advanced vocab terms.

The source listed above has some great information about the process of apple oxidation.

The best thing about practicing science with kids is tapping into their natural gift of curiosity. Kids come up with the best ideas as they question how the world works.

Use one or all of these lesson extensions to explore more about apples with your kids.

Always make sure to have a control group so that you are conducting a true science experiment. Plan out the experiment using the scientific method before beginning.

It would be so much fun for kids to test out different kinds of apples. They can use the best liquid found from this experiment.

This is a great way to test out how well it works at keeping different kinds of apples from turning brown.

After doing the initial experiment your kids may wonder if the kind of apple will effect the browning process.

Many stores sell pre-sliced apples in plastic bags. With this fun experiment, have your kids test to see how apples placed in plastic bags compare to ones being left out in the open.

For a fun variation, kids can test to see if flattened out bags with most of the air removed will effect browning.

They can compare the results of flattened bags to ones having a large amount of air left inside.

Conduct an easy experiment similar to the apple science experiment. Have your kids brainstorm then pick out a few other fruits that also brown once sliced.

If they are not sure if any other fruits change color they can do a science project where they slice a variety of fruits and observe the changes in color.

Then they can test out different liquids and record the results. It would be fun to see if the same liquids had similar results for different fruits.

Make sure to download your free copy of the apple experiment below!

Terms of Use

These worksheets were created by  Nature Inspired Learning  and are for  personal use only for your home, classroom, or public library see full disclosure . All of these apple experiment worksheets are for  non-commercial use .

Two different versions: a guided version and a blank activity sheet.

More Easy Science Experiments

Reader Interactions

October 28, 2021 at 10:22 am

Oh my kids will love this! Thanks for all the information. Can’t wait to try it!

October 30, 2021 at 1:17 pm

Your very welcome Ashley, I hope your kids enjoy the experiment

October 28, 2021 at 10:36 am

What a fun experiment! I am going to have to do this with my class!

Awesome! I hope they enjoy conducting the experiment

October 28, 2021 at 11:51 am

You have so many great tips for doing this experiment! Great idea!

Thank you Laura

October 28, 2021 at 4:22 pm

So many great ideas here that anyone could do! Thanks for sharing!

October 30, 2021 at 1:18 pm

Thank you Kelsey! Yes easy to do even as a spur of the moment activity when cooking with apples

October 28, 2021 at 7:39 pm

I love this apple science experiment! It is a fun way to learn science. Thank you so much for sharing!!!

October 30, 2021 at 1:19 pm

Your very welcome Ada

January 22, 2023 at 11:15 pm

My children love apples. These will be so fun! Julie, on these cold days, do you know how to make fake snow ? Cindy

January 23, 2023 at 11:14 am

I'm not sure about how to make fake snow possibly with baking soda and water (however it wouldn't be safe to eat)? Or if you are able to use a mini snow cone machine that grinds up ice to make "snow" that would be fun too!

August 28, 2023 at 3:30 pm

I'd love the Apple Oxidation Lab freebie, thanks!

August 28, 2023 at 3:34 pm

Hi Farren, There is a sign up form at the end of the post for a PDF version of the activity sheets. Best, Julie

September 04, 2023 at 8:21 pm

I love this so much!

September 05, 2023 at 6:09 am

Hi Stacey! Enjoy, happy exploring

Josie Heflin

September 17, 2023 at 11:10 pm

I'm super excited to do this with my son!!! Thank you so much for this!!!

September 23, 2023 at 9:35 am

You're very welcome! I hope you both have fun.

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Apple browning

• No comments

Make chemistry delicious and informative with this experiment into the natural reaction of food like apples

This practical not only explores oxidisation, but leaves learners with a snack. 

This experiment should take 60 minutes. 

• Eye protection
• Yoghurt pots
• Aluminium foil – students may think light causes browning
• Lemon juice
• Bicarbonate of soda
• Access to water

Health, safety and technical notes 

Read our standard health and safety guidance here .

Wear eye protection.

This is an open-ended problem-solving activity, so the guidance given here is necessarily incomplete

Consider the safety aspects of eating in the lab

Possible approaches

Questions to ask students who need help are:

• Do they need to use a whole apple each time, or can they use tiny slices?
• Would it be best to cut the apple up first, or to get everything else ready first? Is cold water better than warm water?
• Apart from water, what else might you safely try? (e.g. salty water, sugary water, vinegar, lemonade, bicarbonate of soda, anything else?)
• How can you make your tests fair?

Each group could make a presentation to the class of their findings. At the end of each talk, encourage ‘members of the audience’ to ask the speakers any questions, as one might do at any scientific meeting.

As envisaged, the experiment is of low hazard and eye protection will not be needed. If any hazardous substances are chosen, their use should be risk assessed. 

Possible extension

Why is lemon or orange juice squeezed over a fruit salad containing apples, pears or bananas? Find out about the preservatives in your favourite food. 

Additional information

The resources were originally published in the book In Search of Solution P. Borrows, K. Davies and R. Lewin, Royal Society of Chemistry, 1990.

This experiment was based on an idea contributed by  P. Borrows.

• 11-14 years
• 14-16 years
• Practical experiments
• Investigation
• Reactions and synthesis

Specification

• Students should be able to explain reduction and oxidation in terms of loss or gain of oxygen
• Explain reduction and oxidation in terms of loss or gain of oxygen, identifying which species are oxidised and which are reduced.
• 4.5 Explain oxidation as the gain of oxygen and reduction as the loss of oxygen
• C1.1.13 explain oxidation in terms of gain of oxygen
• C3.3a explain reduction and oxidation in terms of loss or gain of oxygen, identifying which species are oxidised and which are reduced
• 7. Investigate the effect of a number of variables on the rate of chemical reactions including the production of common gases and biochemical reactions.
• 8. Investigate reactions between acids and bases; use indicators and the pH scale
• 2. Recognise questions that are appropriate for scientific investigation, pose testable hypotheses, and evaluate and compare strategies for investigating hypotheses.
• 3. Design, plan and conduct investigations; explain how reliability, accuracy, precision, fairness, safety, ethics, and the selection of suitable equipment have been considered.
• 4. Produce and select data (qualitatively/ quantitatively), critically analyse data to identify patterns and relationships, identify anomalous observations, draw and justify conclusions.
• 5. Review and reflect on the skills and thinking used in carrying out investigations, and apply their learning and skills to solving problems in unfamiliar contexts.

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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.

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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!

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Teaching with Jennifer Findley

Upper Elementary Teaching Blog

Apple Oxidation Science Experiment with FREE Science Reading Activity

Science experiments are such an important part of students’ learning. However, sometimes I felt that my science standards didn’t lend themselves to the kind of experiments that my students really needed.

Implementing seasonal themed science experiments was a great way to incorporate engaging science experiments that I felt really benefited my students. This post shares a science experiment with free science reading activity that is perfect for a fall science experiment. This experiment is also great for using text evidence and existing science to support predictions and make conclusions about the results.

Step 1: Read the text about apple oxidation with the “Apple Browning” passage.

Step 2: Using the information from the passage, plan an experiment to test liquids for ascorbic acid OR use the directions page with materials and steps provided.

Step 3: Select a variety of liquids. Examples:

• plain water
• salt water (1/8 tsp of salt, 1 cup of water)
• sugared water (1 tbsp of sugar, 1 cup of water)
• honey water (1 tbsp of honey, 1 cup of water)
• pure lemon juice
• apple juice
• orange juice

Step 4: Students will write down predictions about how each liquid will affect the oxidation process of the apple (using the information they read in Step 1 to support their predictions).

Step 5: Prepare and pour each liquid into its own bowl, cup, or baggie. Be sure to label the liquids and use the same amount of each.

Step 6: Slice an apple into small pieces.

Step 7: Immediately place one apple piece into each liquid. Make sure the liquid is covering the white part of the apple. Leave one piece of apple out of the liquid as the control variable.

Step 8: After 3 minutes, remove the apples from the liquid and place them on a platter. Record observations using the printable chart in the free download.

Step 9: After 6 minutes, observe the apples again and record any new observations.

Step 10: Check predictions and complete the reflection printable. The students will use both the details from the text and their own observations to make their conclusions.

Download FREE Apple Oxidation Printables

Click here or on the image below to download the free directions and science reading activity for this science experiment.

This activity can be done whole class, during a small group science rotation,  or even in small groups. If you do it in small groups, you (or a parent volunteer or support teacher) would need to go around to each group to cut the apple into slices.

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This post was created in collaboration with A Stults.

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Reader interactions.

May 16, 2019 at 6:25 pm

Thank you for sharing, I think this is a great easy way of showing students the process of oxidation.

May 12, 2020 at 3:53 pm

Thats Awesome!

March 21, 2023 at 8:15 am

Thank you for the idea!

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Free Worksheets

Social studies, apple browning science experiment with free oxidation worksheet.

This simple, but fascinating  apple oxidation experiment allows children to learn  why apples turn brown and  what prevents apples from browing with a hands-on apple science experiment.  Try this  apple activity for kids this September with pre-k, kindergarten, first grade, 2nd grade, and 3rd graders too. Simply print  apple worksheet and you are ready to try this  apple browning experiment!

Apple Browning Experiment

Looking for a fun and useful  apple experiment . This  apple browning experiment uses real apples and various liquids you have around your house to hypothesize and discover  what prevents apples from browning . In this simple  apple science , preschoolers, kindergartners, grade 1, grade 2, and grade 3 students will discover  why apples turn brown . Whether you are a parent, teacher, or homeschooler you will love this  apple activities as part of your  apple theme or science centers during September and fall.

What is Oxidation

Oxidation can happen to metals, fruit, and other substances. It simply means a chemical reaction occured that resulting in an electron is removed. When the inside of an apple is cut, the inside is exposed to oxygen in the air, a chemical reaction occurs where an electron is lost through oxidation. The oxidation (visually the browning of the surface of a fruit) can be prevented by removing the oxygen from the equation and vacuum-packing the fruit, adding heat and cooking the apple slices, or by coating the surface with an acidic liquid, like lemon juice.

Let’s explore some common household items and see if any of them can prevent oxidation in apple slices.

Apple Oxidation Experiment

To try this simpler  apple experiment all you need are a few simple materials:

• pen and paper for labeling
• free apple science worksheet (below)
• lemon juice
• baking soda
• small containers

Science experiments with apples

Start by scrolling to the bottom of the post, under the terms of use, and click on the text link that says >> _________ <<. The pdf file will open in a new window for you to save your freebie. Now print off  the pages.

Apple Science Experiment

First things’s first, you need to make a label for each liquid so you don’t forget which one is which. Don’t forget 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.

Now, pour the liquids into separate containers with the labels next to the corresponding containers. Place an apple slice in each container so that it’s submerged in the liquid.

Apple experiment

Wait a few minutes and take out the apple slices. Place the apple slices on a cutting board or plate and put the corresponding labels next to them.  Wait two hours and check on the apples.

Science with Apples

Discuss the progress of the oxidation and write what you are seeing on your apple oxidation worskheet.

Why Apples Turn Brown

Wait another hour and check on the apples. Discuss any new observations and record them on your worksheet.

What Prevents apples from browning

Finally, after 5 hours total, check how brown the apple slices are and record observations on the free worksheet. Your child can draw the oxidized apple slices in the space provided on the worksheet.

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• Plus don’t miss this FUN Apple Crafts Preschool
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Looking for more fun apple and activities and free apple printables? You will love these apple activities for kindergarten and apple activities for preschoolers!

• Math Apple Worksheets (addition / subtraction)
• Super cute and FREE Apple Apple Worksheets Preschool
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• Printable Apple Math – Number Bonds Activity
• Hole-Punching, Count to 20 Apple Activities for Preschoolers – free printable
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• A is for Apple Printable Book for working on beginning sounds – print in black and white or color
• Color the correct apples in these Nouns and Verbs Worksheets
• Apple Theme BUNDLE

Apple Printables

• Simple Johnny Appleseed Coloring Page
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Before you grab your free pack you agree to the following:

• This set is for personal and classroom use only.
• This printable set may not be sold, hosted, reproduced, or stored on any other website or electronic retrieval system.
• Graphics Purchased and used with permission
• All material provided on this blog is copyright protected.

>>  Apple Worksheet  <<

Beth Gorden is the creative multi-tasking creator of Kindergarten Worksheets and Games. As a busy mother of six, she strives to create hands-on learning activities and worksheets that kids will love to make learning FUN! Browse through more than 200,000 pages of FREE worksheets & educational activities for kindergartners! Plus don't miss her other sites www.123homeschool4me.com and www.preschoolplayandlearn.com

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• STEM Activities /
• Crazy chemistry experiments /

Apple Oxidation Experiment

Have you ever noticed that if you slice an apple in the morning, it turns brown by lunch? This is actually a chemical reaction at work! In this experiment, you’ll learn more about how the oxygen in the air around us causes this reaction (also known as oxidation). With a little help from Ziploc bags, test different liquids to see if you can figure out a way to keep apples fresh from morning to noon.

Want to learn more about chemistry without the hassle of gathering materials? Explore 11 fun chemistry experiments with a Chemistry Play Lab from the KiwiCo Store !

Ages: 3 - 4

30 minutes - 1 hour

A little messy

Materials you'll need

• ziploc® brand sandwich bags
• water (1/4 cup)
• lemon juice (1/4 cup)
• vinegar (1/4 cup)
• milk (1/4 cup)
• apple slices
• permanent marker (soft felt-tipped)

Step-by-step tutorial

Gather your materials.

On four Ziploc® brand sandwich bags, write the name of the liquid you’re going to test. Label a fifth bag “nothing” for your control bag. This bag will contain apples with no liquid. That way, you’ll be able to see the difference between a normal apple and the other apples that have been soaked!

Pour the water, lemon juice, vinegar, and milk in separate bags. Make sure to match each liquid to its label.

Place two apple slices in each bag. Seal the bag and lightly shake it so the liquid coats the apple slices. Let them soak for two or three minutes.

Pour any excess liquid out of the bags. Reseal them and check on the apples every 10 to 15 minutes to see what happens. Which ones turn brown? Which ones stay fresh?

When apples are cut, the exposed fruit underneath the skin react with the oxygen in the air, which causes the apple slices to turn brown. This experiment explores how the apple slices react when coated with different liquids, like milk, lemon juice, vinegar, or water. You’ll discover lemon juice is one of the liquids that work best. That’s because lemon juice is very acidic (and why it tastes so sour!) and will react with oxygen before oxygen reacts with the apple. A light spritz of lemon juice will keep your apples fresh without altering their taste too much.

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Science project, why do apples turn brown.

Have you ever bitten into an apple, set it down for a few moments, and found that it has turned brown? This is caused by an enzyme (polyphenol oxidase and catechol oxidase are two common examples) that reacts with oxygen in the air and an iron or copper cofactor in the fruit. A cofactor is a component that is necessary for a certain enzymatic reactions to happen. The fruit starts to oxidize, when electrons are lost to another molecule (in this case the air), and the food turns brown. In other words, it’s like edible rust on your food!

Oxidation can be prevented or slowed down by not allowing oxygen to get to the surface of the fruit. To accomplish this, you can cook the food, which destroys the enzyme. It is also possible to prevent browning without cooking by covering the fruit (preventing air from reaching the fruit), or by lowering the pH on the surface, making it more acidic .

Which liquid do you think will prevent the food from turning brown the best? Why?

• Baking sheet or wax paper
• Labeling tape
• Pen or marker
• Lemon juice
• Any other liquid you want to test
• Any other fruit or vegetable you want to test
• Camera (optional)
• Use the tape to create labels for each type of liquid you will test.
• Place your labels on the baking sheet or wax paper. This is where you will set down your samples for observation.
• Cut each fruit or vegetable into slices at least 1-cm thick. Make sure you have as many slices of each food item as you do liquids to test, plus one more for a control. Have an adult help you cut your samples! Why should the food samples be cut?
• Set out a slice of each food item on the baking sheet or was paper under the heading “Control.” Why is it important to have a control?
• Fill the bowl with enough liquid to fully submerge each sample.
• For each fruit or vegetable you are testing, dip a slice into the liquid with tongs. Be sure to cover the whole slice! Let the extra liquid drip off before placing it under the correct label on the baking sheet or wax paper.
• Rinse out the bowl and repeat until you have made samples with each liquid.
• Record all your observations, taking note of the time. You can also take pictures to document how the food turns brown over several hours.

Lemon juice, Vinegar, clear soda will all prevent food from turning brown quickly. These liquids are acidic, so they will lower the pH of the food surface. Olive oil, will also prevent food from browning, but is less effective than the acids. Water and salt water will also slow the browning of foods.

Lemon juice is the most effective, and by chance, also the most delicious!

Having a control group is necessary because it is important to know how long the food samples will take to turn brown without any liquid added.

The food’s skin protects the inside “meat” of the fruit or vegetable from damage and debris. When a fruit or vegetable is dropped and the skin is poked or broken, the food often goes bad faster. The reason fruits and some vegetables go brown when they are cut is because the part containing the oxygen-reactive enzyme is exposed. There is then a lot of surface area for the air to come in contact with the food. For the most part, brown fruits and vegetables still taste fine, they just do not look very appetizing.

Acids prevent browning because they react with the oxygen that comes into contact with the surface of the sample. Once all the acid (or whatever else is covering the surface) has reacted with the oxygen or the acid has degraded or washed off, then the sample will start to brown again. Stronger acids, like lemon juice, can even denature the enzyme. This means that the enzyme can no longer perform its original function because of its environment.

Digging Deeper

Why doesn’t dried fruit turn brown? What about the fruit drying process prevents enzymatic reaction with oxygen?

Related learning resources

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Bookmark this to easily find it later. Then send your curated collection to your children, or put together your own custom lesson plan.

VanCleave's Science Fun

Your Guide to Science Projects, Fun Experiments, and Science Research

Browning Apple: Experimental Conclusion

By Janice VanCleave

An experimental conclusion is a summary of the investigation.

The photo of the girls raking leaves, is much like an experimental conclusion. Both processes involve collecting materials from different places and putting them in one place. Unlike the pile of leaves, which has no particular organization, an experimental conclusion is organized.

The conclusion should state the hypothesis for the science problem being investigated, and state whether the results of the experiment supported the hypothesis or not. If the results did not support your hypothesis, say so, and then add information about why you think this  happened.

Conclusion Form

My hypothesis for this investigation was:_______________________

The results of the experiment  ( DID, DID NOT) support my hypothesis.

Brief description of the data that you based your conclusion on.

For Example:

For the following question and hypothesis, an example conclusion is outline below.

Questions: What effect does the type of citric fruit covering apple slices have on their browning ?

Hypothesis: Since all citric fruits contain citric acid, any kind of citric fruit covering apple slices will prevent the slices from browning.

Apple slices submerged in canned citric juice had no visible evidence of browning. Control #1 ( apple slices submerged in water)  and Control #2 (apple slices exposed to air) both had an equal degree of browning. NOTE: THESE RESULTS MAY OR MAY NOT BE CORRECT. YOU WILL HAVE TO INVESTIGATE FOR YOURSELF.

Conclusion:

My hypothesis for this investigation is, “Since all citric fruits contain citric acid, any kind of citric fruit covering apple slices will prevent the slices from browning. ” The results of the experiment did support this  hypothesis.

All apple slices that were submerged in canned citric juices showed no signs of browning. To confirm that it was not just being submerged in a liquid, apple slices were summered in distill water. This was one of the two controls, it was labeled Control #1. The second control were apple slices exposed to air. The two control had equal amounts of browning.

Further Investigations–

Often the results of an experiment will bring up questions that lead to further investigations. For examples of further investigation ideas for the “ Browning Apple Investigation ” different kinds of edible acids could be used, such a vinegar. Does the concentration of the acid affect the results?

Send comments and suggestions to ASK JANICE

RETURN TO SCIENCE FAIR PROJECT TEACHING TIPS for the next step

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Why Do Apples Turn Brown? Science Experiment

We’re having apple fever around here this week!  But I’ve been hating how apples turn brown so quickly.  Maybe not as much as my picky 3 1/2-year-old, but annoyed just the same…  So we decided to test a bunch of those methods you see out there for keeping the apples looking fresh.  And why not turn experimentation into a lesson?  So we threw in some Scientific Method for kicks, too. Read on for a fun experiment for kids and what works best for keeping apple slices white.

This apple experiment is a great chance to teach the kiddos about the Scientific Method.  Why should you bother?  The method teaches kids and adults critical thinking and a framework in which to approach any problem, not just ones in science.  You can follow along with the experiment and the method below.  This is a great STEM activity you can do with ingredients right in your kitchen. With the kids home more these days, you’ll be glad you have this quick educational experiment you can pull out of your back pocket anytime!

Plus, to make it super easy for you, we pulled together a helpful lab worksheet, scientific method poster, and easy-to-follow (and print!) experiment instructions. Just fill out the form below and it will be emailed to you right away.

FREE! APPLE SCIENTIFIC METHOD EXPERIMENT AND PRINTABLE

Scientific Method Step 1:  Ask a Question

We hate it when apples turn brown.  For some reason, they just don’t seem as tasty as when you first bite into them.  So our question is:   What is the Best Way to Keep Apples From Turning Brown?

Scientific Method Step 2:  Do Research About Why Apples Turn Brown

I thought it would help the process to first learn what makes apples turn brown in the first place.  Essentially your apple is rusting in a process called oxidation.  Once the apple is cut or bruised, oxygen in the air combines with iron in the apple to form iron oxides.  Enzymes in the fruit (like polyphenol oxidase) make this process go faster.  The oxidation process is also what causes metals to rust.

You can reduce browning by slowing oxidation in three different ways.  1) Cook the apples 2) reduce the exposure to oxygen or 3) reduce the pH of the fruit.  Doing both by covering in an acidic liquid is the best way to keep apples from turning brown without cooking.

Scientific Method Step 3:  Form a Hypothesis

It’s time to formulate a hypothesis…  Before the experiment, ask the kids a couple of questions.  Their opinions will be their hypothesis.

• Which method do you think will work the best?
• Which one do you think will taste the best?

Scientific Method Step 4:  Design an Experiment

It seems like everyone has an idea of the best way to keep apples looking fresh!  We asked our friends for ideas (ummm, I mean I looked on Pinterest.)  Here’s what we tried…  Be sure to add a control that will show you how the apple turns brown with no treatment. A control is the part of the experiment that tests what an apple would do naturally, without treatment.

• Honey  (1 teaspoon honey mixed with 1 cup water)
• Lemon juice  (1 teaspoon juice mixed with 1 cup water)
• Salt  (1/2 teaspoon salt mixed with 1 cup water)
• Vitamin C (1 tablet crushed and dissolved in 1 cup of water)
• Lemon-lime soda
• Carbonated water (bubble water)
• Experiment Control (we used the apple core)

Now it’s time to try all of these ingredients.

• First set out 8 bowls big enough to cover the slice completely with the solution.  Label each bowl so you don’t mix up the solutions.
• Make each of the solutions in a separate cup.
• Cut one apple into 8 slices of approximately the same size.  If you use more than one apple, you’re adding variables to the experiment as some apples may brown at different rates than the others.
• Place an apple slice into each bowl.  You can use the core as the control.
• Immediately cover with each solution, one per bowl.

Scientific Method Step 5:  Record and Analyze Data

Now comes the waiting period.  We checked after 5 minutes and decided to wait another 5 minutes before pulling the apples out of the solution.  You can choose your own time period based upon how fast the apples are turning brown.  Then:

• Pour off the solution and inspect each apple for brown color.  Record levels.
• Taste apples and record impressions.

Our lab worksheet will make it super easy to record and analyze the data!

Scientific Method Step 6:  Draw a Conclusion

To help draw a conclusion from the experiment, ask the kids:

• Which one tastes the best?
• Which ones kept the apples the whitest?

You and the kiddos should test this for yourself, but here’s what we found in the experiment:

• Plain water doesn’t work.  Carbonated water is a touch better, but not that much.  Plus it gives a slightly bitter taste to the apples.
• Salt keeps the apples really white, but yuck! did not taste good.  Probably need to try this with less salt.
• Lemon juice works well too but also changes the flavor of the apples.  Good for fruit salad, maybe not for plain apple slices.
• Vitamin C works just ok, but definitely not well enough to be worth the hassle of crushing tablets.
• The lemon lime soda worked too, but they tasted like apples soaked in soda.  Duh, right?  Too candy-like and not really that healthy, so out.

So the winner is…HONEY!  The apples weren’t quite as white as with salt and lemon, but the taste was sooo yummy.  Like unadulterated apples, just deliciously sweet ones.

Even More Fall STEAM Fun for Kids!

Join us as we explore all things FALL with STEAM Explorers . Kids will love learning physics with football, doing a leaf color-changing experiment, snacking on apple chips, exploring the beauty of sunflowers, and more! You'll love the helpful standards-based learning, printables, and tools that make STEAM (science, technology, engineering, art, & math) exploration easy!

32 thoughts on “Why Do Apples Turn Brown? Science Experiment”

Great experiment idea! It’s simple enough for little ones, and tasty too! Thank you for featuring me this week!!

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This is a great experiment. I know that apples turn brown based on oxidization.

Thanks so much! Glad you enjoyed it.

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I love your experiment and the look on your sweet girl’s face with the “HMMM.” And good to know – honey!!! We also tried lemon juice in the past but then my son wouldn’t eat them because like you said – flavor!!

Thanks Kristi! I had to put the hmmm… picture in. It’s one of my favorites :)

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Great experiment!! I did this with my 4 year old. We though honey tasted amazing to the rest!!! Salt was our whitest…..but our tap water was actually whiter in comparison to most..makes me wonder what is in our tap water….hmmmm…another project on the horizon. :) Thanks again!

That definitely makes me curious about your water!! Thanks for stopping by :)

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