Experiment with Plant Pigments

Anthocyanins are really interesting pigments! They are responsible for the red color in the tips of emerging tulip shoots. They are found in a lot of fruits and vegetables, too.
In the fall the pigments in plant leaves change as the temperature changes. The same pigments can look different in different environments. Try a simple experiment using materials that are commonly found.

Emerging tulips show red anthocyanin pigment in their first leaves.

Try this experiment!
(*Adult supervision necessary for this experiment.)
You will need:

  • *bleach
  • white vinegar
  • water
  • purple grape juice
  • 3 clear glass containers

Before You Start: Record in Your Notebooks

  • What do you predict will happen to the grape juice when you put it into each liquid?
  • Smell, but do not touch each liquid. How are the bleach, the vinegar, and the water different? How are they the same?
  • Describe the color of the grape juice

Now Experiment:

Put a tablespoon each of bleach, vinegar, and water in 3 clear glass containers. Add a few drops of grape juice to each.

Describe what happens to the pigment in each liquid.


Compare what you saw with your prediction. Was your prediction correct? Write a sentence describing what happened to the anthocyanin pigment in each liquid.
Extension: What other "red" plant materials could you test in this experiment?

What's Happening?

Pigments can change color in different environments. Our solutions have very different characteristics; one is alkaline (bleach), one is neutral (water), and one is acetic (vinegar).The soils that plants grow in also have different characteristics that can affect anthocyanin pigments. These are the pigments responsible for the red tips of emerging tulip shoots in the spring.