LE ROY PENNYSAVER & NEWS - JANUARY 26, 2014
Glow In The Dark Jell-O and Other Science Projects
by Lynne Belluscio
This past weekend, the Jell-O
Museum had an exhibit at the
Rochester Museum and Science
Center. Luckily we had some
very dedicated volunteers who
helped – Cheryll Fernaays,
Shelia Furr, Jacob and Evan
Williams, and Joanne Graham.
Their job was to explain how
the gelometer worked. How to
capture bubbles in Jell-O. And
why Jell-O has brain waves.
But what seemed to capture
everyone’s attention was the
glow-in-the-dark Jell-O. It’s
made with a cup of boiling
water and a cup of tonic water.
First you dissolve the Jell-O in
the cup of boiling water and
then you add a cup of cold tonic
water and stir. Put the Jell-O
in the refrigerator until it sets.
You’ll need a black light to
make the Jell-O glow, but no
matter which flavor you use, the
Jell-Owill glow bright blue. The
bottle of tonic will glow too.
For the exhibit, I put the dish
of Jell-O in a shoebox with a
small battery operated black
light. I suspect there are a lot
of kids eating glow-in-the-dark
Jell-O tonight. You can also
make glow-in-the-dark Jell-O
Jigglers. Again, substituting
half the water for tonic water.
The magic ingredient is the
quinine. The glow-in-the-dark
Jell-O is edible, but it does
have a little bit of a bitter taste
because of the quinine.
The quinine molecules absorb
the ultra-violet light emitted
by the black light, but almost
instantaneously re-emit the
light. Some energy gets lost in
the process, so the emitted light
has a longer wavelength than
the absorbed radiation, which
makes this light visible and
causes the material to appear
to ‘glow’.
Quinine has an interesting
story. It was derived from the
bark of a tree found in Peru.
A Jesuit priest discovered the
medicinal properties of quinine
and brought it back to Rome.
The tree was often called the
Jesuit Tree and Peru exported
quinine for a long time. It was
used to cure malaria. Peru
forbid the exportation of seeds
or plants, but businessmen from
the Netherlands were able to
smuggle seeds out of Peru and
established huge plantations
in Java.
By 1930, nearly 97% of the
world’s quinine came from
Java and was controlled by
the Dutch. During World War
II, the Japanese captured the
plantations in Java, and the
Germans captured the quinine
supplies in the Netherlands.
Attempts were made to create
synthetic quinine but it wasn’t
until 1944 that it became
available, but it was too late
to save the lives of tens of
thousands of Allied soldiers.
Another edible experiment
that can be done with Jell-O is
an experiment with sinkers and
floaters. Kids can predict which
fruits or vegetables sink or float
in Jell-O. You make a batch of
Jell-O and throw in the fruit and
see what happens. You can also
try cutting the fruit up to see if
the size makes any difference.
(At what point does the apple
sink?) And of course, you can
eat the experiment when you
have recorded your results.
There are some fruits that
won’t work. Fresh pineapple,
kiwi, papaya, guava, and
fresh ginger have an enzyme
that interacts with the protein
molecules in the gelatin and
prevents the Jell-O from
setting. Canned pineapple is
OK, because during the canning
process, the pineapple is heated
above 150 degrees and the
enzymes are destroyed.
There are several other
experiments that can be done
with Jell-O, such as seeing how
much water can be added to the
Jell-O before it won’t set. In
fact, the Jell-O Company at one
time had a flavored drink – like
Kool Aide – that didn’t have
any gelatin in it. It was called
Zowie and as far as anyone
knows, no one has ever seen a
package of Zowie.
