Apple Science Lemon Juice Experiment for Fall STEM

How do your kids feel about those apple slices that have turned brown or the rotten spot they just bit into? Let’s try the apple science with lemon juice experiment! Why do apples turn brown and can you prevent it? Do all apples turn brown at the same rate? Let’s try to answer these burning apple science questions with an apple science lemon juice experiment that is pretty quick and easy to set up at home or in the classroom. We paired this with our Apple 5 Senses Science Activity.

EASY APPLE SCIENCE LEMON JUICE EXPERIMENT FOR KIDS

All this week we are going to be enjoying real apple science activities while we practice reading one of our favorite Fall books, Ten Apples Up on Top by Dr. Seuss.

WHY DO APPLES TURN BROWN? HOW CAN WE STOP IT?

We have all checked out the bad spot on an apple and we have all opened a container in our 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. My son tested out the brown slices of his favorite apple the honey crisp and declared it still ok. Not all apples are similar in their rate of browning, but does lemon juice on apples really work to stop or slow the browning process?

THE SCIENCE BEHIND THE 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, cut into slices, the enzymes in the apple react to the oxygen in the air causing oxidation. The apple produces melanin to protect the apple which is the brown you see. We watched this short youtube video on Why do Apple Turn Brown? which digs deeper into the exact science of polyphenol oxidase (PPO) enzymes. It’s a mouthful!

LET’S EXPERIMENT WITH APPLES

This is a great experiment to set up using the scientific method for early elementary age kids. Younger kids will have tons of fun too. Read more about scientific method here and print out our free scientific method worksheets or basic science activity journal pages to add to any experiment.

OUR EXPERIMENT

We wanted to see which apple turned brown the fastest and if lemon juice actually stopped the apple slice from turning brown.

SUPPLIES FOR APPLE SCIENCE LEMON JUICE EXPERIMENT

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 {optional}

SET UP

Our set up was super easy since we had just been testing out all the apples. We labeled paper plates with the apple’s name. I then cut two wedges out of each apple. We placed one wedge in the small dish and the other on the plate along side the whole apple. Squeeze a little lemon juice over each slice and mix to coat evenly. Dump out excess juice. Do this for each apple.

Now wait and be patient. Be observant. If you want to 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 for drawing conclusions later.

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 SLICE.