What exactly is jello made from?

Jello is tasty, colorful and fun to eat, but what's in it? One of its ingredients, gelatin, comes from animals. Marshall Brain breaks down the chemistry of jello and gelatin in this episode.

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Episode Transcript

Speaker 1 (00:00):
Welcome to Brainstuff from house stuff works dot com where
smart happens. Hi. I'm Marshall Brain with today's question, what
exactly is jello made from? When you go to the
grocery store and you buy a box of jello, you're

(00:21):
buying three things. First, there's gelatin. Second, there's sugar or
some kind of artificial sweetener combined with artificial flavors, and
then third there's food coloring. When you get home, you
add a fourth ingredient, which is water. The gelatin and
jello is what lets you transform it into all sorts
of different shapes. What exactly is gelatin? Gelatine is just

(00:44):
a processed version of a structural protein called collagen that
is found in many animals, including humans. Collagen actually makes
up almost a third of all the protein in the
human body. It's a big fibrous molecule that makes skin, bones,
and tendons both strong and somewhat flexible. As you get older,

(01:05):
your body makes less collagen, and individual collagen fibers become
cross linked with each other. You might experience this as
stiff joints from less flexible tendons, or wrinkles from the
loss of skin elasticity. The gelatin you eat in jello
comes from the collagen in cow or pig bones, hoofs,

(01:25):
and connective tissues. To make gelatin, manufacturers grind up these
various parts and pre treat them with either a strong
acid or a strong base to break down the cellular
structures and release proteins like collagen. After pre treatment, the
resulting mixtures boiled. During this process, the large collagen protein

(01:47):
ends up being partially broken down, and the resulting product
is called gelatin. The gelatin is easily extracted because it
forms a layer on the surface of the boiling mixture.
Gelatin is a common ingredient and foods because it's really versatile.
It can be used as a jelling agent as in jello,
as a thickener, as an emulsifier, and as a stabilizer.

(02:09):
You'll find it in a variety of foods, from yogurt
to chewing gum. Here's some of the foods that commonly
contain gelatin. There's gummy bears, sour cream, cream, cheese, cake,
icing and frosting, marshmallows, soup, sauces and gravies, canned hams,
and chicken. The list goes on and on. Gelatine is
even used to make the coating for pills that makes

(02:32):
them easier to swallow. It's also in cosmetics, lozenges, and ointments.
When you buy a box of jello or another brand
of gelatine at the grocery store, you get a small
packet of powdered gelatin with artificial flavorings and colors. At
room temperature. The gelatin protein is in the form of
a triple helix. This is a fairly ordered structure, not

(02:54):
unlike that of d NA. With DNA, two chains of
nucleotides are twisted together in a spiral pattern. In a
gelatine protein, there are three separate chains of amino acids
also known as polypeptide chains, that have lined up and
twisted around each other, and the helix is held together
by weak bonds that form between the amino acids that

(03:17):
end up on the inside of that coiled structure. To
make a gelatine mold, you have to add boiling water
to the powdered gelatin. Then you stir the mixture for
about three minutes until the gelatine dissolves completely. What happens
to the gelatine when you add the boiling water the
energy of the heated water is enough to break up

(03:37):
the weak bonds holding the gelatin strands together. The helical
structure falls apart, and your left with free polypeptide chains
floating around in a water solution. The next step is
to add cold water and stick the dissolved gelatin in
the refrigerator to chill for several hours. When you cool
down the mixture, those polypeptide chains begin to reattach and

(04:01):
reform the tight triple helix structure. However, the chilling process
is slow and the individual strands have been widely dispersed
by mixing, so the helixes aren't perfectly formed this time.
In some places there are gaps in the helix, and
in others there's just a tangled web of polypeptide chains.

(04:21):
When the gelatine solution is chilled, water gets trapped inside
these gaps and pockets between the chains. The protein net
that's left after chilling gives the gelatine molded shape, and
the trapped water provides the characteristic jiggle that makes jello
a popular food for kids to eat. For more on

(04:42):
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