Gelatin
Key Facts
Other Names:
Gelatine
Formula:
Not applicable
Elements:
Carbon, hydrogen, oxygen, nitrogen, and others
Compound Type:
Not applicable
State:
Solid
Molecular Weight:
Not applicable
Melting Point:
Not applicable
Boiling Point:
Not applicable
Solubility:
Soluble in hot water and glycerol; insoluble in most organic solvents
Overview
Gelatin (JELL-ah-tin) is a mixture, not a compound. Mixtures differ from compounds in a number of important ways. The parts that make up a mixture are not chemically combined with each other, as they are in a compound. Also, mixtures have no definite composition, but consist of varying amounts of the substances from which they are formed. Gelatin is a mixture of water-soluble proteins with high molecular weights. It typically occurs as a brittle solid in the form of colorless or slightly yellow flakes or sheets, or in powder form, with virtually no taste or odor. It absorbs up to ten times its own weight when mixed with cold water and dissolves in hot water. When a solution of gelatin in hot water is cooled, it takes the form of a gel, a jelly-like material perhaps most commonly seen as the popular dessert called JELL-O™. Gelatin is also available in a number of other commercial forms, such as Knox Gelatin™, Puragel®, and Gelfoam®. Gelatin has been known to humans for many centuries, but it was not widely marketed until the late 1890s. Its name comes from the Latin word gelatus, which means "frozen."
How It Is Made
Gelatin is made by boiling animal parts with high protein content, such as skin, ligaments, tendons, cartilage, and bones. The boiling process breaks down molecular bonds between individual collagen strands in the animal tissue. Collagen is a structural protein found in bone, cartilage, and connective tissue. The collagen formed by this process can be further disintegrated through additional boiling with either acid or alkali. Type A gelatin is produced when collagen is boiled in an acidic solution, and type B gelatin is produced by boiling collagen in an alkaline solution.
Most of the animal parts used to make gelatin come from cattle and pigs and are left over from meat and leather processing. Gelatin can also be made from fish. One of the oldest forms of gelatin is isinglass, made from the swim bladders of fish. Jewish and Muslim dietary laws prohibit believers from eating pork, so some gelatin is made without pig parts. Vegetarians and vegans do not eat any animal products, so gelatin manufacturers also make similar products using vegetable carbohydrates, such as agar and pectin. These vegetarian gelatins are not true gelatin, which is always made from animal proteins.
Common Uses and Potential Hazards
People discovered gelatin centuries ago and experimented with various uses for it. In the early 1800s, for example, gelatin was included in the food served to French soldiers as a source of dietary proteins. In the 1890s, Knox Gelatin™ was sold as a cure for dry fingernails. Manufacturers claimed that dry fingernails were caused by a lack of protein and that eating gelatin would cure the condition. No scientific evidence exists for that claim, but Knox Gelatin™ became popular among consumers nonetheless.
In 1900, the Genesee Pure Food Company began selling flavored gelatin under the name JELL-O™. In the early 1900s, the company began distributing booklets containing recipes using JELL-O™, eventually giving out more than 15 million such booklets. JELL-O™ eventually became one of the most popular desserts in the United States and other countries. It has been used to make a variety of pleasant tasting, attractive looking desserts molded into many different shapes. Cooks have combined gelatin with water, milk, soft drinks, other liquids, whipped toppings, or mayonnaise to change its taste and texture. The product is often served with fruits or vegetables as a salad. Gelatin is also combined with marshmallows, jellybeans, jelly, yogurt, gummy candies, ice cream, and margarine to produce desserts of many textures and flavors. The product is sometimes recommended as a fat substitute because it provides volume in a diet without adding many calories. Some people include gelatin products in their diets as a way of increasing protein intake. Although plain gelatin is almost entirely protein, it actually has relatively little nutritional value.
Interesting Facts
- Before refrigerators became common, gelatin was used to keep foods fresh and attractive. Packing a food in gelatin prevents oxygen from reacting with the food and causing spoilage.
- Synchronized swimmers sometimes use gelatin to hold their hair in place during performances.
- Aspic is a clear jelly often made with gelatin. It is a component of many elegant dishes, one of which, "Oeufs de caile en aspic et caviar" (Quail eggs in aspic with caviar), was served in first class on the doomed steam ship Titanic in 1912.
Gelatin has many other uses, including:
- As a raw material for the manufacture of capsules and gels in the production of drugs;
- As a way of holding silver halide (silver bromide and silver iodide) crystals in place on photographic films and plates;
- In the manufacture of blocks used to determine the possible effects of various types of ammunition on human flesh;
- As a binder that holds sand on sandpaper or to make certain types of paper products (such as playing cards) bright and shiny;
- As an additive in various types of cosmetics and skin treatments;
- In the manufacture of meshes used in the repair of wounds and in the production of artificial heart valves;
- In the production of certain types of cement;
- For the manufacture of light filters used in theatrical productions and for other specialized purposes;
- As a culturing medium for bacteria;
- As a stabilizer and thickener for certain types of foods, especially ice cream and some other dairy products;
- In the manufacture of printing inks;
- As an additive in the production of plastics and rubber products.
Words to Know
A strong base. A collection of two or more elements and/or compounds with no definite composition. A large, complex compound made of long chains of amino acids. Proteins have a number of essential functions in living organisms.For Further Information
"Gelatin." WholeHealthMC.com. http://www.wholehealthmd.com/refshelf/substances_view/1,1525,10151,00.html (accessed on December 22, 2005).
"A History of JELL-O™ Brand." Kraftfoods.com. http://www.kraftfoods.com/jello/main.aspx?s=&m=jlo_history (accessed January 4, 2006).
"The Jell-O Museum." The Genesee Pure Food Co. http://www.jellomuseum.com/#Page1. (accessed on December 22, 2005).
"What Exactly Is Jell-O Made From?" How Stuff Works. http://home.howstuffworks.com/question557.htm (accessed on December 22, 2005).
"What Is Gelatin." PB Leiner. http://www.gelatin.com/ (accessed on December 22, 2005).
Wyman, Carolyn. JELL-O: A Biography. Fort Washington, PA: Harvest Books, 2001.
See Also
Collagen
This is the complete article, containing 1,029 words
(approx. 3 pages at 300 words per page).
