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Science Experiment Project- A Lemon Lifesaver for Apple

Updated on July 16, 2011

Apple and Lemon Oxidation Science Experiment

Here is an easy science fair experiment to help kids learn how to Save that apple! Lemons can truly be a life saver in many instances and they are a great fruit to use when learning about science. Think about an apple . .have you ever wondered why when you slice an apple it starts to turn brown? Well with a little help from lemon juice you can slow down the browning of an apple. This is an easy science experiment that you and your kids will always understand how to keep that apple from turning brown!

Stop The Apple from Browning

The lemon can stop the oxygen in the air from turning into a very reactive gas. It reacts fast to whatever it comes into contact with. And that is why foods that are exposed to air can change quickly in appearance. This is all because of oxidation. Oxidation is the reaction of oxygen molecules with certain substances. The reaction involves the loss of electron or hydrogen or gain of oxygen. Substances that cause oxidation is known as the oxidant or also called as the oxidizing agent. This lemon experiment shows what a lifesaver to the apple it is.

Science Experiments with Lemons
Science Experiments with Lemons

Easy Lemon Experiement with Fast Results

So what is happening to the apple is that the moment the apple is cut, the cut part allowing oxygen to come in contact with open area. The apple starts turning brown when oxygen from the air reacts with the phenolic compounds found in the apple. Just like the process of rusting.

Science Fair Experiments are fun
Science Fair Experiments are fun

1- Lemon To the Rescue

Save the Apple from Oxidation!

What you will need:

  • A few apples
  • Knife
  • Lemon Juice

2-What To Do:

  • Cut the apple in four parts.
  • Squeeze lemon juice (Squeezing the juice is find but I like to use a brush to spread it on) on two of them.
  • Let all the apple pieces stand for a few hours.

An browning apple
An browning apple

Lemon Juice Saver

Lemon juices contain vitamin C which is an antioxidant and it prevents oxidation.
Lemon juices contain vitamin C which is an antioxidant and it prevents oxidation.

3- What Happens: To The Apple

The exposed and untreated apple surface quickly undergoes a chemical change and therefore destroys cells. As it reacts with oxygen in the air the apple surfaces start to brown and turn dark, And the apples pieces that were not treated with lemon do not turn brown. That's because the vitamin c (ascorbic acid) in the lemon juice slows down and disrupts the chemical in the fruit and the oxygen in the air. And so it starts to oxidize therefore turning brown.

Lemons to the Rescue

Enzymatic Browning In Apples

The process of browning is called enzymatic browning.
Enzymatic browning happens not only in apples, it also occurs in other fruits such as banana avocados and vegetables like potato. The oxidation of phenolic compounds can be slowed down when the apple is treated with a sour fruit juice like lemon juice. Lemon juices contain vitamin C which is an antioxidant that prevents oxidation.

Litmus Paper

You can make your own Litmus Paper
You can make your own Litmus Paper

The Lemon - Lifesaver

Poison control centers used to recommend vinegar or lemon juice as an antidote for some poisons. This experiment shows why.

For this science experiment you will need:

  • A few drops of lemon juice or vinegar
  • Litmus paper
  • A few drops of ammonia
  • Rubber gloves

What to Do

  • First put your rubber gloves on, for it is a good idea as you do not want to irritate your skin.
  • Apply a few drops of lemon to one strip of litmus paper.
  • Then add a few drops of ammonia to a second strip. Be very very careful when handling the ammonia.
  • Then apply a few drops of lemon to the spot made by the ammonia.

Experiment Results

Results from experiment
Results from experiment

Lemons Make What Happens

The strip with the lemon juice on it turns pink. The strip with ammonia added turns green. When you add lemon to the green ammonia spot it will return to its orginal reddish purple color.

In this Experiment Why Do the Colors Change:

The pink color indicates the presence of acid because lemon is a mild acid, a non metal combined with hydrogen.

The green color indicates the presence of alkali because ammonia is an alkali or otherwise it is known as a "base", a metal combined with hydrogen. The "litmus" paper returns to its original color when the ammonia is acted against -neutralized-by the lemon which is its chemical opposite.

So now you are asking what does all this have to do with poison? Ammonia is poisonous if someone drinks it. Since lemon neutralizes ammonia, they used to recommend as a temporary antidote until you could get to a doctor. Currently if by accidnet someone drinks a poison like ammonia the antidote is to drink a lot of milk and or water.


Lifesaver Comments

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    • drbj profile image

      drbj and sherry 7 years ago from south Florida

      I loooove your science experiments - especially the really easy ones like adding lemon juice to apples. This one I can do with my eyes shut - well, maybe one eye shut.

      Thanks for the well-presented info.

    • Jai Warren profile image

      Jai Warren 7 years ago from Dallas, Deep Ellum, Texas

      You are now, officially, the "Acid Queen". No, not that acid! lol First vinegar and now lemons. It's unbelievable how many uses this fruit has. Your images are really fantastic, you'll have to give me some tips. Thanks Shari, Ciao! :)

    • Cagsil profile image

      Cagsil 7 years ago from USA or America

      Hey Shari, this was really cool. I enjoyed this one. It reminded me of being in school. LOL! It was certainly a flashback. Thank you. :)

    • wavegirl22 profile image

      Shari 7 years ago from New York, NY

      ~ drbj - funny bit i forgot what a scientist I used to be. This 60Dc is really bringing alot of "me" out in it! Thanks for stopping by and leaving me such a nice comment!

      ~Jai Warren - and to think I was just turning into a football freak!!! 4 Hubs and a giant repeat is how I spent my day! And how was yours ;) Always a treat to see you John :)))))

      ~ Cags - Yes it has been aa flashback of a day for me .. and as you can see I had a few little friends helping me out! Glad to see you here:)

    • Sandyspider profile image

      Sandy Mertens 7 years ago from Wisconsin, USA

      Yummy! I need to try this experiment.

    • wavegirl22 profile image

      Shari 7 years ago from New York, NY

      Sandyspider - :) let me know how it comes out! Thanks for stopping by and saying hi!

    • shazwellyn profile image

      shazwellyn 7 years ago from Great Britain

      Hey virginia... you did it again! welldone :)

    • wavegirl22 profile image

      Shari 7 years ago from New York, NY

      shaz- again . .thanks . . and I am so ready for phase II. United we stand. . divided we fall! :)

    • billyaustindillon profile image

      billyaustindillon 7 years ago

      Another great science experiment - I will try this one at home. It has good practical uses also - thanks for this one Shari.

    • wavegirl22 profile image

      Shari 7 years ago from New York, NY

      billyaustindillon - my pleasure to share these great experiments . .been a few years since I have had to re create them (my daughter will be 21 this Halloween!) but my little friends that are in a few pics of some of the other experiemnts love to do them so I am back in business:) Stay tuned there are a few more up my sleeve!

    • wavegirl22 profile image

      Shari 7 years ago from New York, NY

    • profile image

      jane 6 years ago

      i need a science fair project im in grade 9

      and i would like it to deal with using litmus paper.

    • profile image

      janeenglish 6 years ago

      i need a science fair projects for grade 9

      something regarding litmus paper?

      please . i want something just so i can get a good mark nothing like go to nationals

      k thanks

    • profile image

      miriam :P 6 years ago

      can this work with other fruits??? and thnx sooo much this is pretty amazing but easy . :)

    • wavegirl22 profile image

      Shari 6 years ago from New York, NY

      miriam :P - the citric acid will keep avocados and bananas from turning brown as well!

    • profile image

      master mayo =D 5 years ago

      I really like the project that all you guys do. i am going to do a brown bananas project.

    • wavegirl22 profile image

      Shari 5 years ago from New York, NY

      master mayo - come back and let us know if your banana findings!

    • profile image

      Adel 4 years ago

      I want to know if when you eat the apple when the lemon is applied to it the apple taste different.

    • wavegirl22 profile image

      Shari 4 years ago from New York, NY

      Obviously the apple with have a taste of lemon.

    60Dc A Winning Team

    theblackedition at work ;)
    theblackedition at work ;)
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