Learn and observe how an apple turns brown with this experiment.

Materials:

  • Apple
  • Apple cutter or permission and supervision to cut your apple
  • Cups or containers or plastic zip lock bags
  • Items to soak your apples in such as water, baking soda, milk, lemon juice, lime juice, orange juice, vinegar, and salt
  • Plates
  • Tape and marker to make labels

Steps:

1. With permission and supervision cut your apple into slices

2. Add your labels to your cups, containers, or plastic bags depending on what items you will put in your cup to soak your apples in

3. Add your items to your cups with labels. I added milk, water with baking soda, lime juice, water, lemon juice, orange juice, vinegar, and salt water. Also make sure you have one cup with nothing in it which I labeled air to be your control group or your cup with no change, so you have something to compare your other cups with your substances to or your experimental groups. 

Make your predictions on what you think will happen to each apple slice in the different cups. 

What substances do you think will prevent browning if any or what substances do you think will make the browning occur faster if any?

4. Add your apple slices to your cups

5.  Let your apple slices sit in your cups for about 15 minutes to absorb or soak up the substances

6. Take your slices out of the cups and set them on a plate with labels. I made my labels by using a piece of tape and writing with my marker on the tape so it didn’t stain the plates

7. Let your apples sit for at least five hours and check on them about every hour to see what happens don’t forget to make your predictions

3:04pm first taken out of the cups

4:00pm

5:00pm

6:14pm

7:08 pm

8:21 pm

10:48pm

10: 51pm

11:13pm

Apples have the enzyme polyphenol oxidase (ppo), this enzyme reacts with oxygen when the apple is sliced open and causes browning. The browning occurs because the reaction between the enzyme and the air produces melanin which causes the brown color. 

In order to slow the browning, you have to prevent the oxygen from reacting with the enzyme, you can do this by adding the different substances.

The substance that did the best at slowing down the browning was the lemon juice because it contains vitamin c. the oxygen will react with the vitamin c first and slow the browning

Next time you pack sliced apples for lunch you can add a few drops of lemon juice to help prevent them from turning brown

How did your experiment go? What substances did you use and what happened?

Congratulations on completing your experiment