GELATIN. Gelatin (also gelatine, jelly in Britain, jelly powder in Canada, and gelée in France) is a flavorless, transparent thickener derived from animal collagen that dissolves when heated and congeals when cooled, allowing foods to set. This versatile ingredient provides unique textural and sensory properties to both savory and sweet foodstuffs such as mousses, gummy bears, Turkish Delight, nougat, jellied soups, Bavarian cream, aspic, and Jell-O.
Gelatin is composed of protein molecules, made up of chains of amino acids. When placed in liquid, the molecules swell and then dissolve, and the chains separate. After cooling, they re-form as tightly as before. In the warmth of the mouth, they melt, providing excellent flavor release. This property and gelatin's easy digestability and absorption by the body makes gelled desserts appropriate for children, invalids, and the elderly.
Nutritional value of gelatin was recognized as early as the Napoleonic Wars (1800–1815) when the French used it as a source of protein during the English blockade. Commercial gelatin contains no fat or cholesterol and few calories, making it popular with people who have diet and heart concerns. Commercial manufacturers claim that gelatin promotes nail and hair growth, as well as flexible joints and healthy bones. However, the protein in gelatin is missing an amino acid and thus is not absorbed as a complete protein by the body.
The discovery of gelatin was probably serendipitous: When animal bones and hides are boiled in water, the broth that results will set upon cooling. From the Middle Ages through the eighteenth century, making gelatin was a daylong, laborious process in which cattle hooves were boiled for six hours. The stock was clarified as it dripped through a jelly bag, boiled again, and then allowed to sit. Not surprisingly, production was limited to wealthy households with many servants. Another early source of gelatin in the Middle Ages was hartshorn (antlers of the hart deer).
Today, the substance is manufactured commercially all over the world. In the United States most gelatin is derived from pig skin. Strictly speaking, this is not a kosher practice (although interpretations vary), and it is not permissible under Islamic dietary law. An alternative, isinglass (made from the air bladders of sturgeon), is acceptable to the religious and vegetarians. Another alternative is agar, made from a variety of red seaweed, commonly used in Japan where it is known as kanten and used in the manufacture of ice cream. Cattle form the basis of gelatin in France and Britain, raising safety concerns about transmission of mad cow disease even in the United States where some gelatin is imported from Europe.
Commercially manufactured gelatin is packaged in ¼-ounce envelopes of desiccated granules; paper-thin sheets, known as leaves (used in jelled Central and Eastern European desserts and aspics); and meltable blocks (Great Britain). In Latin America, gelatin is often mixed with milk or cream instead of water for the popular creamy desserts. In Russia, gelatin encases pigs' feet and other meats.
Aside from home and restaurant cooking, gelatin has wide application in the food industry where its functional properties are used to gel, thicken, stabilize, emulsify, bind, film, foam and whip prepared foods. Among other items, gelatin is incorporated into marshmallows, cake mixes, frostings, bakery glazes, meringues, ice cream, coffee, and powdered milk.
Elaborate molded jellies began to grace aristocratic British banquet tables in the fourteenth century. In the Late Medieval period (the 1400s) through the 1500s, cooks made savory and sweet jellied dishes using meat, chopped fine, mixed with cream or almond milk that was flavored with spices, rosewater, or sugar to fashion creations known as cullis, gellys, or brawn. In 1754, the first English patent for the manufacture of gelatin was granted. During the Victorian era, copper, and later aluminum, molds were introduced, which made possible the presentation of tall, shimmering creations. Unflavored dried gelatin became available in 1842 from the J and G Company of Edinburgh, Scotland.
Gelatin had an esteemed role in classic French cuisine. Escoffier's legendary Guide Culinaire (1903) includes a chapter on aspic jellies (savory gels) in which the great chef named two kinds: one flavored with champagne; the other with sherry, Marsala, or Madeira. Surprisingly, he mused that aspics might be even more important than stock, the bastion of Gallic cooking, because a cold meat, poultry, or fish entree (known as chaud-froid ) is nothing without its glimmering coating of aspic. He warned that the value of the aspic decreased in direct proportion to its increasing firmness. The ideal was a softer consistency so aspic could even be served in a sauceboat. Gelatin also figured in many classic French desserts like blanc-mange, charlottes, mousses, and Bavarian creams.
Gelatin in the United States
In America, in 1845, Peter Cooper, inventor of the steam locomotive, secured a patent for a gelatin dessert powder called Portable Gelatin, requiring only the addition of hot water. The same year, the J and G Company began exporting its Cox Gelatin to the United States. The new formulas never gained much popularity, however, and as late as 1879 when the classic Housekeeping in Old Virginia was published, editor Marion Cabell Tyrer, while admitting that jelly made of calves and hogs was "more troublesome," claimed it was more nutritious than Cox's or Nelson's desiccated formulas. Plymouth Rock Gelatin Company of Boston patented its Phosphated Gelatin in 1889. In 1894, Charles Knox introduced granulated gelatin, making the brand something of a household word. This opened the way for a plethora of American recipes that gained popularity, particularly during the 1950s when chiffon pie and tomato aspic (made of gelatin and tomato juice) became staples.
Although Jell-O is considered déclassé in upscale restaurants, gelatin was resurrected and frenchfied by American chefs in the late 1990s, who reverted to calling the sweets "gelées." These creative formulas have been limited only by imagination since virtually any liquid can be used—coffee, champagne, grape and beet juice, rosé wine, sangria, and fruit poaching liquids. What began in the Middle Ages as an elite food has come full circle and returned to gourmet status.
See also Escoffier, Georges-Auguste ; Medieval Banquet ;Proteins and Amino Acids ; Icon Foods ; Women and Food .
Shapiro, Laura. Perfection Salad: Women and Cooking at the Turn of the Century. New York: Farrar, Straus and Giroux, 1986.
Belluscio, Lynne. The JELL-O Reader. Le Roy, N.Y.: Le Roy Pennysaver, 1998. A collection of forty articles by the director of the Le Roy Historical Society. Also contains material on gelatin.
Berzok, Linda Murray. "My Mother's Recipes: The Diary of a Swedish American Daughter and Mother." In Pilaf, Pozole, and Pad Thai: American Women and Ethnic Food, edited by Sherrie A. Inness. Amherst, Mass.: University of Massachusetts Press, 2001. The social meaning, for women, of Jell-O molded salads.
Linda Murray Berzok
Jell-O has become a cultural icon in the United States. Invented by Pearle Bixby Wait in 1897, (the name Jell-O was coined by his wife, May), this flavored gelatin's longevity is credited to its convenience for dessert, its popularity, especially with children, and its ability to inspire smiles, jokes, and playfulness. Beginning with strawberry, raspberry, orange, and lemon, Jell-O in the early twenty-first century comes in twenty-three flavors, including white sparkling grape, watermelon, and passion fruit. Strawberry is the best seller. Over a million boxes are sold every day; Salt Lake City, Utah, is the number-one consumer city.
Aside from thousands of inventive serving ideas (including one from 1930 for forcing set Jell-O through a potato ricer), Jell-O has spawned collectors (of original boxes, early advertising, recipe booklets, molds, glasses); Jell-O shots (alcoholic treats made by mixing in liquor); Jell-O wrestling (sometimes in the nude in large vats); the Jell-O Museum in Le Roy, N.Y.; an attempt to measure the brain waves of Jell-O; and countless websites.
Not everyone thinks Jell-O is benign. During the 1950s, when femininity was defined as docility, complicated molded constructions with fruits precisely placed according to pattern were popular, raising questions about a foodstuff that controls and keeps things in their place. One researcher claims that the marketing of Jell-O depicts women as inept homemakers. It is hard not to wonder about the larger social message of "perfection salad," a prescribed concoction of cabbage, celery, and red peppers in tomato Jell-O, popular at the turn of the twentieth century. Such prescription becomes a symbol of conformity and stifles creativity.
Gelatin is a protein substance derived from collagen, a natural protein present in the tendons, ligaments, and tissues of mammals. It is produced by boiling the connective tissues, bones and skins of animals, usually cows and pigs. Gelatin's ability to form strong, transparent gels and flexible films that are easily digested, soluble in hot water, and capable of forming a positive binding action have made it a valuable commodity in food processing, pharmaceuticals, photography, and paper production.
As a foodstuff, gelatin is the basis for jellied desserts; used in the preservation of fruit and meat, and to make powdered milk, merinque, taffy, marshmallow, and fondant. It is also used to clarify beer and wine. Gelatin's industrial applications include medicine capsules, photographic plate coatings, and dying and tanning supplies.
Until the mid-nineteenth century, making gelatin was a laborious task. Calves' feet were loaded into a large kettle that was then placed over a fire. The feet were boiled for several hours after which the liquid was strained and the bones were discarded. After setting for 24 hours, a layer of fat would rise to the top. This was skimmed off and discarded. Sweeteners and or flavorings were added to the liquid and it was poured into molds and allowed again to set.
By the 1840s, however, some producers were grinding the set gelatin into a fine powder or cutting it into sheets. One of them was Charles B. Knox, a salesman from Johnston, New York, who hit on the idea of making gelatin more convenient after watching his wife Rose make it in their kitchen. Knox packaged dried sheets of gelatin and then hired salesmen to travel door-to-door to show women how to add liquid to the sheets and use it to make aspics, molds, and desserts. In 1896, Rose Knox published Dainty Desserts, a book of recipes using Knox gelatin.
The first patent for a gelatin dessert was issued in 1845 to industrialist and inventor Peter Cooper. Cooper had already made a name for himself as the inventor of the Tom Thumb steam engine. He had also made a fortune in the manufacture of glue, a process similar to that for making gelatin.
In 1897, Pearl B. Wait, a carpenter and cough medicine manufacturer, developed a fruit-flavored gelatin. His wife, May Davis Wait, named his product Jell-O. The new product was not immediately popular and Wait sold the rights to the process to Orator Francis Woodward, owner of the Genesee Food Company, for $450. Sales continued to limp along until 1902 when an aggressive advertising campaign in Ladies Home Journal magazine generated enormous interest. Sales jumped to $250,000.
The use of gelatin in food preparation increased six-fold in the 40-year period from 1936-1976. Today, 400 million packages of Jello-O are produced each year. Over a million packages are purchased or eaten each day.
In the field of photography, gelatin was introduced in the late 1870s as a substitute for wet collodion. It was used to coat dry photographic plates, marking the beginning of modern photographic methods. Gelatin's use in the manufacture of medicinal capsules occurred in the twentieth century.
Animal bones, skins, and tissue are obtained from slaughterhouses. Gelatin processing plants are usually located nearby so that these animal byproducts can be quickly processed.
Acids and alkalines such as caustic lime or sodium carbonate are used to extract minerals and bacteria from the animal parts. They are either produced in the food processing plant or purchased from outside vendors.
Sweeteners, flavorings, and colorings are added in the preparation of food gelatin. These can be in liquid or powdered forms and are purchased from outside vendors.
Inspection and cutting
- 1 When the animal parts arrive at the food processing plant, they are inspected for quality. Rotted parts are discarded. Then, the bones, tissues, and skins are loaded into chopping machines that cut the parts into small pieces of about Sin (12.7cm) in diameter.
Degreasing and roasting
- 2 The animal parts are passed under high-pressure water sprays to wash away debris. They are then degreased by soaking them in hot water to reduce the fat content to about 2%. A conveyer belt moves the degreased bones and skins to an industrial dryer where they are roasted for approximately 30 minutes at about 200° F (100° C).
Acid and akaline treatment
- 3 The animal parts are soaked in vats of lime or some other type of acid or akali for approximately five days. This process removes most of the minerals and bacteria and facilitates the release of collagen. The acid wash is typically a 4% hydrochloric acid with a pH of less than 1.5. The alkaline wash is a potassium or sodium carbonate with a pH above 7.
- 4 The pieces of bone, tissue, and skin are loaded into large aluminum extractors and boiled in distilled water. A tube running from the extractor allows workers to draw off the liquid that now contains gelatin. The liquid is sterilized by flash-heating it to about 375° F (140° C) for approximately four seconds.
Evaporating and grinding
- 5 From the extractor, the liquid is piped through filters to separate out bits of bone, tissue or skin that are still attached. From the filters, the liquid is piped into evaporators, machines that separate the liquid from the solid gelatin. The liquid is piped out and discarded. The gelatin is passed through machines that press it into sheets. Depending on its final application, the gelatin sheets are passed through a grinder that reduces them to a fine powder.
Flavoring and coloring
- 6 If the gelatin is to be used by the food industry, sweeteners, flavorings, and colorings may be added at this point. Pre-set amounts of these additives are thoroughly mixed into the powdered gelatin.
The packaging process is automated, with preset amounts of gelatin poured into overhead funnels through which the gelatin flows down into bags made of either polypropylene or multi-ply paper. The bags are then vacuumed sealed.
Gelatin manufacturers must adhere to stringent national and international food processing requirements. These regulations include but are not limited to cleanliness of the plant, equipment and employees; and allowable percentages of additives, flavorings, and colorings.
Automated and computerized technologies allow the processors to preset and monitor ingredient amounts, time and temperature, acidity and alkalinity, and flow levels. Valves are installed along pipelines to allow for continuous sampling of the product.
Gelatin is processed to varying "bloom" values that measure the gel strength or firmness. The desired strength corresponds to the manner in which the gelatin will be used. The bloom value is technically measured and monitored throughout the production process.
Since 1986 when the presence of bovine spongiform encephalopathy (BSE), also known as mad cow disease, was reported in Great Britain, there has been much concern about the processing of beef bones for the production of gelatin. In 1989, the United States Food and Drug Administration (FDA) banned the importation of cattle from the Department of Agriculture's list of of BSE-designated countries. However, a 1994 FDA ruling allowed the continued importation of bones and tissues for the production of pharmaceutical grade gelatin.
By 1997, however, the FDA held hearings to reconsider its decision. After interviewing gelatin processors, the agency found that while gelatin has not been implicated in the spread of BSE, officials are not convinced that the manufacturing processing is extracting all possible agents that are responsible for the disease. It was generally agreed that beef sources carry more of a risk than those from pork, that bones carry a higher risk than skins, and that alkaline processing is more effective than the acid-extraction method. These findings will certainly affect the gelatin-processing industry in the next century.
Where to Learn More
Harvey Lang, Jenifer, ed. Larousse Gastronomique. New York: Crown Publishers, 1988, reprinted 1998.
Marwick, Charles. "BSE sets agenda for imported gelatin." Journal of American Medical Association (June 4, 1997): 1,659.
Leiner Davis Gelatin. http://www.gelatin.com/ (June 29, 1999).
Kraft Foods. http://www.kraftfoods.com/ (June 29, 1999).
Sterling Gelatin. http://www.sterlinggelatin.com (June 29, 1999).
Carbon, hydrogen, oxygen, nitrogen, and others
Soluble in hot water and glycerol; insoluble in most organic solvents
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.
- 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.
Gelatin is an edible protein made from the skin, bones, and ligaments of animals. It is clear, usually colorless or pale yellow, odorless and tasteless, and dissolves in water. The hot solution is liquid, but as it cools, it “gels,” forming a semisolid, which is soft and flexible, yet firm enough to hold any shape into which it may be molded or cut. A familiar example of gelatin is the clear, sticky substance found on parts of a chicken leg after it has been cooked.
Most manufactured gelatin comes from pork skins and the skin and bones of cattle. These contain a tough, fibrous protein called collagen. First they are treated with either acids or bases (alkali) to dissolve hair, flesh, and other unwanted substances. Then they are cooked in hot water. The heat converts the collagen to gelatin, which dissolves in the water. The solution is purified and the water is removed by evaporation. Finally, the pure, solid gelatin is ground into flakes or powder.
Like all proteins, gelatin is a polymer. That is, its molecules are built up of smaller units called amino acids linked together by chemical bonds like beads along a string. In collagen three amino acid strands, each about a thousand amino acid units long, are twisted together as a sort of braid. Individual “braids” are joined by chemical bonds, making very tough weblike structures. Heating in water breaks some of the bonds. Therefore, gelatin consists of shorter strands, with fewer chemical bonds between them. These smaller fragments dissolve in water. As a hot gelatin solution cools, some of the bonds form once again, causing the solution to thicken. Cooling further, the protein strands form a three-dimensional mesh, with water filling the holes of the mesh. The resulting “gel” is soft enough to cut, yet rigid enough to hold its shape.
Gelatin cannot be a major source of protein in the human diet because it lacks tryptophan, one of the amino acids essential for human nutrition. Its main use in the food industry is to provide texture and shape to foods, especially desserts, candies, and dairy products. Gelatin also has many nonfood uses. Made into capsules, it encloses drugs for the pharmaceutical industry and microscopic drops of ink for “carbonless” copying papers. A layer of gelatin binds lightsensitive chemicals to the surface of photographic film. Gelatin is also used as glue for objects as diverse as match heads and the bindings of telephone books.
Gelatin is an edible protein made from the skin, bones and ligaments of animals. It is clear, usually colorless or pale yellow, odorless and tasteless, and dissolves in water . The hot solution is liquid, but as it cools, it "gels," forming a semi-solid, which is soft and flexible, yet firm enough to hold any shape into which it may be molded or cut. A familiar example of gelatin is the clear, sticky substance found on parts of a chicken leg after it has been cooked.
Most manufactured gelatin comes from pork skins and the skin and bones of cattle. These contain a tough, fibrous protein called collagen . First they are treated with either acids or bases (alkali) to dissolve hair, flesh, and other unwanted substances. Then they are cooked in hot water. The heat converts the collagen to gelatin, which dissolves in the water. The solution is purified and the water is removed by evaporation . Finally, the pure, solid gelatin is ground into flakes or powder.
Like all proteins , gelatin is a polymer . That is, its molecules are built up of smaller units called amino acids linked together by chemical bonds like beads along a string. In collagen three amino acid strands, each about a thousand amino acid units long, are twisted together as a sort of braid. Individual "braids" are joined by chemical bonds, making very tough web-like structures. Heating in water breaks some of the bonds. Therefore, gelatin consists of shorter strands, with fewer chemical bonds between them. These smaller fragments dissolve in water. As a hot gelatin solution cools, some of the bonds form once again, causing the solution to thicken. Cooling further, the protein strands form a three-dimensional mesh, with water filling the holes of the mesh. The resulting "gel" is soft enough to cut, yet rigid enough to hold its shape.
Gelatin cannot be a major source of protein in the human diet because it lacks tryptophan, one of the amino acids essential for human nutrition . Its main use in the food industry is to provide texture and shape to foods, especially desserts, candies, and dairy products. Gelatin also has many non-food uses. Made into capsules, it encloses drugs for the pharmaceutical industry and microscopic drops of ink for "carbonless" copying papers. A layer of gelatin binds light-sensitive chemicals to the surface of photographic film. Gelatin is also used as glue for objects as diverse as match-heads and the bindings of telephone books.
gelatin or animal jelly, foodstuff obtained from connective tissue (found in hoofs, bones, tendons, ligaments, and cartilage) of vertebrate animals by the action of boiling water or dilute acid. It is largely composed of denatured collagen, a protein particularly rich in the amino acids proline and hydroxyproline. The process of manufacture is a complex one that involves removing foreign substances, boiling the material (usually in distilled water in aluminum vessels to prevent contamination), and purifying it of all chemicals used in freeing the gelatin from the connective tissues. The final product in its purest form is brittle, transparent, colorless, tasteless, and odorless and has the distinguishing property of dissolving in hot water and congealing when cold. In contact with cold water it takes up from 5 to 10 times its own weight and swells to an elastic, transparent mass. Gelatin, being readily digested and absorbed, is a good food for children and invalids. It is important in fine cookery as a vehicle for other materials, in the form of jellied soups, molded meats and salads, and frozen desserts. Preparations of it are used in the home manufacture of jam, jellies, and preserves to ensure jellification of fruit juices. It is used in the drying and preserving of fruits and meats, in the glazing of coffee, and in the preparation of powdered milk and other powdered foods. Bakeries use it in making meringues, eclairs, and other delicacies. In confectionery making it is used as the basis of taffy, nougat, marshmallows, and fondant. Ice cream manufacture employs it to maintain a permanent emulsion of other ingredients and thus to give body to the finished product. In scientific processes gelatin is widely employed, being used in electrotyping, photography, waterproofing, and dyeing, and in coating microscopic slides. It is used as a culture medium for bacteriological research and also to make coatings for pills and capsules, for court plaster, and for some surgical dressings. It affords a base for ointments and pastes, such as toothpaste; it is an emulsifying agent useful in making liquid combinations and various sprays. In its less pure forms gelatin is known as glue and size. Vegetable gelatin, or agar, is derived from East Indian seaweeds.
gel·a·tin / ˈjelətn/ (also chiefly dated gel·a·tine ) • n. a virtually colorless and tasteless water-soluble protein prepared from collagen and used in food preparation as the basis of jellies, in photographic processes, and in glue. ∎ (usu. blasting gelatin) a high explosive consisting chiefly of a gel of nitroglycerine with added cellulose nitrate.