Keeping It Fresh!
Learn how you can keep a sliced apple fresh and ready to eat by testing different solutions that may keep the fruit from browning.
Fun Facts/Information:
- A process called oxidation is what will cause your apple to brown. This is the same process that causes metal to rust.
- There are three ways to slow down oxidation and reduce browning: Cooking the apple, reducing the PH of the apple, or reducing its exposure to oxygen.
- The pH value of something tells us how acidic or basic it is.
Learning Objectives:
- Identify and evaluate which solution most effectively slows down the browning of an apple, based on observable evidence.
- Explain how and why a solution slows oxidation and reduces apple browning.
Materials:
- Apple
- Apple Cutter or knife (adult use only)
- Six small bowls
- Six sticky notes or labels
- Pen or pencil
- Honey
- Lemon Juice
- Salt
- Lemon-lime soda
- Club Soda
- Tap water
- Teaspoon
- ½ teaspoon
- 1 cup measuring cup
- Three spoons
- Notepad or paper
Safety Considerations:
- Adult supervision is required when slicing the apple in this experiment.
- Check the materials list to ensure there are no allergens for anyone participating in this activity.
Procedures
- Use your notebook to record a hypothesis for this experiment. A hypothesis is an educated guess of what will happen during the experiment that can then be tested.
Research Question: Which solution will be the most effective in slowing down the apple's browning? - Create a label for each solution to label the bowl that it will be in. You will need the following labels: honey, lemon juice, salt, lemon-lime soda, club soda and control. Place a label on each of the six bowls.
- Add one cup of lemon-lime soda to the bowl designated for it.
- Add one cup of club soda to the bowl designated for it.
- Add one cup of tap water to the bowl labeled honey, then add 1 tsp of Honey and mix with a spoon.
- Add one cup of tap water to the bowl labeled salt, then add ½ tsp of salt and mix.
- Add one cup of tap water to the bowl labeled lemon juice, then add 1 tsp of lemon juice and mix.
- Add nothing to the bowl labeled control.
- Ask an adult to use an apple cutter or knife to slice the apple. It will need to be cut into 6 even slices.
- Use the apple cutter to cut the apple into 6 equal pieces.
- Immediately place each slice of apple into a bowl.
- Set a timer for 15 minutes. Leave apple slices in the bowls until the time goes off.
- When the timer goes off, remove all apple slices from the bowls.
- Observe any changes that have occurred with your apple. Record the observations on your paper.
- Taste each apple slice!
Discussion Questions
- Ask yourself: Was your hypothesis correct?
- Which solution kept the apple from browning the least?
- Look up the typical PH for the solutions tested. How is this information significant to your results?
- Which apple slice tastes the best?
Extensions
- Test out other fruits and vegetables with this process, such as Avocado, Banana, and Potato.
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