Transcript for the Piece Audio version of What Is Jello?

It's pretty easy to guess what most of your food is made of. The meat in your hamburger probably came from a cow, the bun was
made from grain, the ketchup from tomatoes, and so on. There is
one kind of food, however, that might have you guessing animal,
vegetable or mineral for the whole meal. But no more, since we'll learn about Jello on today's Moment of Science7.
Jello is a trademark name for gelatin, a food that people
have enjoyed for generations. To answer the question animal,
vegetable, or mineral: gelatin is an animal product. It is
prepared by soaking the bones, skin, or connective tissue from
pigs or cows in a bath of mild hydrochloric acid solution. After
this, the animal products are heated in distilled water for many
hours, and finally boiled. The fluid that collects from this
process is drawn off. What's left is dried, and ground into a fine, pale yellow powder. This is unflavored gelatin, the basis of all gelatin salads, desserts, and drinks.
Gelatin is valuable as a food because it is pure protein and
it is easy to digest. A gelatin made from vegetable protein,
called agar agar, is made for vegetarians.
When powdered gelatin is stirred into hot water and then
chilled, it forms the jiggly, gelled product that we are most
familiar with. This gelled product is not strictly a solid or a
liquid. Technically it's a colloid: a liquid suspended in a
solid framework. As the hot mixture cools off, the long strands
of animal protein lock together into a solid framework, trapping
tiny droplets of liquid water in the process. It's these
droplets of water, trapped in a mesh of animal protein, that hold
all the coloring and flavoring in your favorite gelatin dessert.

A Moment of Science7
Copyright 8 2009 Indiana University

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"Gelatin" in the McGraw-Hill Encyclopedia of Science and Technology, 6th ed. (New York, 1987).
"Gelatin" in the Worldbook Encyclopedia.
Jok Church, "Beakman and Jax", Universal Press Syndicate, December 11, 1994.
Harold McGee, On Food and Cooking: the Science and Lore of the Kitchen (New York: Scribner, 1984).
Writer: Eric Sonstroem.