C&EN: WHAT'S THAT STUFF? JELL-O

CORINNE A. MARASCO, C&EN WASHINGTON

JELL-O Chemistry in a box.
COURTESY OF KRAFT FOODS INC.

It wiggles, it jiggles, and you probably loved it when you were a child. (I bet some of you still do.) It's a simple concept with incredible staying power: Jell-O has been "America's Most Famous Dessert" for more than 100 years, largely because of its simplicity and versatility.

If you look at the ingredients on a box of Jell-O, you'll see that it's essentially sweetened, flavored, and colored gelatin. Gelatin is basically processed collagen, which is a structural protein in animals' connective tissue, skin, and bones. Collagen also makes up about one-third of all the protein in the human body. Collagen is composed of glycine, proline, and hydroxyproline, as well as other amino acids.

Structurally, collagen is composed of three polypeptide chains that are wound together into an -helix--like three strands of spaghetti twisted together--and held together by hydrogen bonding. Collagen chains are also cross-linked by covalent bonds--important in food because as an animal ages, the cross-linking increases and its meat gets tougher. The tanning process also increases cross-linking and converts skin to leather.

When collagen is heated in water, the triple helix unwinds and the chains separate, becoming random coils that dissolve in water: That's gelatin. As the gelatin cools, the molecules try to regain the original helical structure and eventually bond together as they lose energy.

Gelatin molecules consist principally of repeating sequences of glycine-proline-hydroxyproline triplets, and bonding occurs at points along these strands, forming pockets that trap large amounts of liquid, resulting in a semisolid colloid. All colloids have a disperse phase and a continuous phase; that is, one substance is dispersed throughout another substance. In Jell-O, the disperse phase is solid gelatin and the continuous phase is water. Gelatin can absorb a tremendous amount of water--up to 10 times its weight.

According to the Gelatin Manufacturers Institute of America (GMIA), pork skin, cattle bones, and cattle hide are the predominant raw materials used to make gelatin. The raw materials are washed, soaked in acid or lime, and washed again several times. Then the materials are boiled several times to extract the gelatin. The gelatin is filtered, concentrated, chilled, and either cut into ribbons or extruded as noodles and dried. Once dried, the gelatin is ground into the required particle size, depending on its intended use. The final product is brittle, transparent, colorless, tasteless, and odorless.

Gelatin is used primarily in the food, pharmaceutical, and photographic industries. Most of the gelatin produced is consumed in gelatin desserts and confections such as marshmallows and gummy candies. It's also used as an emulsifier, stabilizer, or thickener in foods such as ice cream, sour cream, meat aspics, and cake frostings.
In the pharmaceutical industry, gelatin is used to make the outer shells for hard and soft capsules; it served as a blood plasma substitute during World War II. Gelatin is also used in preparing the silver halide emulsions in the production of photographic paper and film. According to GMIA, a brand-new application for gelatin is in the paint ball industry, which uses gelatin to construct paint balls.

Gelatin is an incomplete nutritional protein because it lacks tryptophan, an essential amino acid. Jell-O itself has little nutritional value apart from energy--80 calories for a typical serving. For example, the list of ingredients on a box of strawberry Jell-O is sugar, gelatin, adipic acid (for tartness), less than 2% of artificial flavor, disodium phosphate and sodium citrate (to control acidity), fumaric acid (for tartness), and the colorant red 40.

According to "Jell-O: A Biography" by Carolyn Wyman (Harcourt, 2001), Jell-O had modest beginnings. Peter Cooper, inventor of the Tom Thumb steam locomotive and founder of Cooper Union College, took out the first U.S. patent for a gelatin dessert in 1845. Beyond obtaining the patent, Cooper did little with it. In 1897, Pearl B. Wait decided to enter the rapidly expanding packaged food business and focused on developing a fruit-flavored version of Cooper's gelatin. It was Wait's wife, May, who named it Jell-O, for reasons unknown today. She may have been referring to the way it had to jell before being eaten. The "O" was a popular ending for product names at that time. The first Jell-O flavors were raspberry, lemon, orange, and strawberry. Wait tried to sell Jell-O door-to-door, but he lacked the resources to market it properly.

Wait sold the Jell-O business in 1899 to Orator Woodward, a successful entrepreneur, for $450. Woodward's first-year sales of Jell-O were so poor that, after seeing stacks of unsold cases of Jell-O during a plant tour, he offered to sell the business to his plant supervisor for $35--and was turned down. But he increased advertising, and by 1902, Woodward had to double the size of his plant to keep up with demand for the quarter-million-dollar Jell-O business.

Wyman's book illustrates how Jell-O's culinary evolution paralleled changes in American society. It was marketed as a simple, inexpensive dessert to women in the early 20th century; as a way to stretch food during the Great Depression; as a convenient dessert when convenience foods were introduced in the 1950s; and as edible entertainment beginning in the 1990s. It's a testament to American ingenuity that Jell-O can also be used to make finger paint, dye your hair, clean the dishwasher, scrub the shower, and deodorize cat litter.

Here are some amazing but true facts about Jell-O that will amuse your friends and family:

Every day, an average of 758,012 boxes of Jell-O are purchased in the U.S.
As immigrants passed through Ellis Island, they were often served a bowl of Jell-O as a "Welcome to America" treat.
When hooked up to an electroencephalograph machine--an instrument that records the electrical activity of the brain--Jell-O demonstrates movement virtually identical to the brain waves of a healthy adult man or woman.
Fresh or frozen pineapple contains an enzyme that prevents Jell-O from setting. Canned pineapple can be used because the canning process eliminates the enzyme.

So go have some fun with Jell-O. Bring it to your next party. I think I'll make some Jell-O with my sons this weekend and relive my childhood, too.