Apple Science - Why do they turn brown?

Materials:

1. One apple or you could try two different varieties of apples

2. plate

3. knife to cut a couple apple slices

4. small bowl (optional)

5. marker to label you apple if you use more than one variety

6. lemon juice

Instructions

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

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

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

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.

5: Now wait and be patient. Be observant. If you want, set out a timer to get an accurate measurement of the time it takes for each apple to turn brown.

Questions to think about:

• 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?

• What else could you try besides lemon juice?

How Does Lemon Juice Keep the Apple 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. Ascorbic acid works because oxygen will react with it before it reacts with the polyphenol oxidase enzyme in the fruit.

Idea taken from Little Bins Little Hands: https://littlebinsforlittlehands.com/apple-science-lemon-juice-experiment-fall-stem/