Why Are Apples Different Colors? Let’s Answer That Question at a Microscopic Level With the uHandy Microscope.

As well as being nutritious and delicious, apples are a fruit that can be enjoyed all year round. But some of you may wonder, why are there so many different colors? Well, it all has to do with a little something called: anthocyanin.

The color of apple skins is due to the amount of anthocyanin present in the cells of the apple peel, the more anthocyanin, the redder the apple.

So using the uHandy Microscope, let’s take a peek at the cells in an apple peel, the flesh of an apple, as well as the seeds!

How to

We will use both the Lo-Mag Lens and the Hi-Mag Pro Lens in our examination of the apple peel, but first let’s get our sample!

Using a knife, slice a thin strip of peel from the apple. The thinner the peel the easier it will be to observe the cells in the peel.

Note: Safety first, adults may wish to assist kids/students with the cutting.

Apple Peel: The image on the left is from the Lo-Mag Lens and the image on the right is from the Hi-Mag Pro Lens. The red speckles show the presence of anthocyanin.

 

Additionally, we can also look at the flesh of the apple. Cut a thin slice from the apple and place it on the slide to observe it under the Hi-Mag Pro Lens.

Underneath the microscope there is no color in the flesh of the apple. This is because this part of the apple is primarily made up of water and sugars, and lacks pigment cells.

 

Finally, let’s take a look at the apple seeds! There isn’t any preparation necessary for the Lo-Mag Lens, just lean in carefully and observe the outside of the seed. Before using the Hi-Mag Pro Lens, use a pair of tweezers to carefully remove the outer skin of the apple seed and place the skin of the seed on the Circular Slide for observation.

Apple Seed: The image on the left is from the Lo-Mag Lens and the image on the right is from the Hi-Mag Pro Lens.

Supplemental Information

Apples are home to two distinct types of pigment cells: chlorophyll, responsible for the green hue, and anthocyanin, which imparts the vibrant red tones.

When apples are young and unripe, they showcase that signature greenness thanks to a surplus of chlorophyll. However, as they mature and bask in sunlight, the chlorophyll starts to break down. As this happens, the apple begins producing more anthocyanin, the true artist behind the red palette.

Interestingly, green apples belong to a separate variety, where chlorophyll's dominance over anthocyanin maintains their green shade throughout ripening.

You know where else anthocyanin likes to hang out? Red or purple fruits and veggies like blueberries, cranberries, and eggplants. These pigment molecules are like pH chameleons – their color morphs depending on the environment's acidity. When things turn acidic, they go deep red; around a pH of 4 or 5, they chill in a colorless state; and when the pH skyrockets above 7, they rock a regal purple. So yeah, anthocyanin can moonlight as a pH level gauge!