“What if” questions often lead us to wild science adventures. (Admittedly, my definition of “wild” changed slightly since I had kids). So recently when we successfully extracted chlorophyll from maple leaves (read about it here), the natural “what if” question that floated to my mind was “what if we take the extracted chlorophyll and put it back into the plant?” “Would the white flowers turn green, if we stick them into extracted chlorophyll?” In other words, can we use chlorophyll as a coloring agent?
Or better yet “what if we take chlorophyll out of one plant and put it in another?” And this is exactly what we set out to do! Do you want to try it with us?
Plant Science: Chlorophyll as a coloring agent
What you need:
is the post on how we extracted it)
Green Food Coloring
Start by talking with your kids about how plants drink (here
is our discussion). Our working hypothesis for this experiment was that, if we place white flowers in a cup with extracted chlorophyll the white flowers would turn green. And possibly the green leaves would look greener.
We had one
sample of chlorophyll extracted with the help of alcohol. Now we needed another sample of chlorophyll extracted without alcohol. We didn’t have enough maple leaves left on the trees in our yard (too many maple leaf projects), but luckily I had a nice bag of spinach in a fridge. I was planning to use it for my salad (you see the sacrifices we do for science in our house…).
To extract the color from the spinach, I put a bag of washed spinach in a food processor. (I washed it because at this point I was still thinking; mmm maybe there will be some left for me to eat), but if you are not planning to eat this spinach, you can skip washing. I blended spinach until it was completely processed into a foamy green … (Is it just me or it bears a stunning resemblance to pond slime?)
At this point I decided that I will dedicate all of my spinach to science.
I started straining spinach mush through a cheesecloth in the following manner (warming: your fingers will turn green and stay green).
But I soon realized that I was wasting my time. The plants that we were planning to stick into our green mush would be able to extract the liquid as needed.
So, now we had chlorophyll extracted from spinach and chlorophyll extracted from maple leaves with alcohol. To make it even more exciting we decided to add one more glass tinted green with green sprinkles. (I don’t know how these particular sprinkles made it into our house since I don’t let my kids consume things like that).
I can only imagine what powerful chemicals are added to these sprinkles to make them color the water like this.
We also added a cup with green food coloring. (We use a lot of food coloring for our science experiments. So much so that I even buy it in bulk!)
We also had a control cup with plain water that didn’t fit into the shot.
Ask older kids to write down their predictions. Encourage younger kids to make a guess which cup will have the greenest flowers, which flowers will be the least affected, etc. They might enjoy making BEFORE and AFTER drawings.
Some possible discussion questions:
1. What other things we can use as a natural (or not so natural) green dye?
2. What are some ways people can use green dyes?
Day 1 – Looking pretty
Day 2 – Oh-oh! Are you surprised alcohol killed flowers? On the other hand, the food coloring tinted flowers nice and green.
Day 3- It’s all downhill from here for most of our flowers, except for the ones tinted with food coloring.
. . . . .
Day 10 – You really want to see it? It’s sad! Ok, I warned you.
As you can see on the photo, we failed to put chlorophyll back into plants. Why? When I first started looking for an answer I was surprised to discover that chlorophyll is classified as an effective coloring agent. Yep, it even has a registered E number E141. So if you eat green chips and the ingredient lists E141, know that it was colored using chlorophyll. Apparently, not all E things are bad for you. Chlorophyll is also known in scientific community as a natural green 3. My kids were surprised to learn that there is plenty of chlorophyll in our own fridge. Spinach, kale, broccoli is all high in chlorophyll.
An interesting fact that I discovered in my later and more academic searches is that processing conditions play an important role in the stability of extracted chlorophyll. Anything from temperature to the level of oxygen can impact the degradation of chlorophyll. So one of the reasons we failed to tint the flowers with extracted chlorophyll can be the wrong conditions. Another one can be the quality of extracted chlorophyll (i.e. spinach was not fresh enough). My kids said that we should keep trying. What do you think? Do we have a chance?