gelatin

1. 1. A colorless or slightly yellow, transparent, brittle protein formed by boiling the specially prepared skin, bones, and connective tissue of animals and used in foods, drugs, and photographic film.
   2. Any of various similar substances.
2. A jelly made with gelatin, used as a dessert or salad base.
3. A thin sheet made of colored gelatin used in theatrical lighting. Also called gel.

[French gélatine, from Italian gelatina, diminutive of gelata, jelly, from feminine past participle of gelare, to freeze, from Latin gelāre.]

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.

Background

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.

Raw Materials

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.

The Manufacturing
Process

Inspection and cutting

• 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

• 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

• 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.

Boiling

• 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

• 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

• 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.

Packaging

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.

Quality Control

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.

The Future

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

Books

Harvey Lang, Jenifer, ed. Larousse Gastronomique. New York: Crown Publishers, 1988, reprinted 1998.

Periodicals

Marwick, Charles. "BSE sets agenda for imported gelatin." Journal of American Medical Association (June 4, 1997): 1,659.

Other

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).

[Article by: Mary McNulty]

A protein extracted after partial hydrolysis of collagenous raw material from the skin, white connective tissue, and bone of animals. It is a linear polymer of amino acids, most often with repeating glycine-proline-proline and glycine-proline-hydroxyproline sequences in the polypeptide linkages. See also Protein.

The unique characteristics of gelatin are: reversible sol-to-gel formation, amphoteric properties, swelling in cold water, film-forming properties, viscosity-modifying properties, and protective colloid properties. Gelatin contains 26.4–30.5% glycine, 14.8–18% proline, 13.3–14.5% hydroxyproline, 11.1–11.7% glutamic acid, 8.6–11.3% alanine, and in decreasing order arginine, aspartic acid, lysine, serine, leucine, valine, phenylala-nine, threonine, isoleucine, hydroxylysine, histidine, methionine, and tyrosine. Absence of only two essential amino acids—tryptophan and methionine—makes gelatin a good dietary food supplement.

The principal uses of gelatin are in foods, pharmaceuticals, and photographic industries. Other uses of industrial gelatin are in the field of microencapsulation, health and cosmetics, and plastics.

[JEHL-uh-tihn] An odorless, tasteless and colorless thickening agent, which when dissolved in hot water and then cooled, forms a jelly. It's useful for many purposes such as jelling molded desserts and salads, thickening cold soups and glazing chaud-froid preparations. Gelatin is pure protein derived from beef and veal bones, cartilage, tendons and other tissue. Much of the commercial gelatin today is a by-product of pig skin. Until the advent of commercial gelatin in the late 19th century, jelled dishes were not very popular because housewives had to make their own jelling agent by laboriously boiling calves' feet or knuckles. Their only alternative was to use either the hard-to-obtain isinglass (gelatin from fish air bladders) or carrageen (a dried seaweed product). Granulated gelatin is the most common form of unsweetened commercial gelatin on the market. It's packaged in boxes of 1⁄4-ounce envelopes and is also available in bulk. Generally, 1 envelope of gelatin will jell 2 cups of liquid. It's important to soak gelatin in cold liquid (whatever the recipe directs) for 3 to 5 minutes before dissolving it. This softens and swells the gelatin granules so they will dissolve smoothly when heated. Not as readily available as granulated gelatin is leaf (or sheet) gelatin, which comes in packages of paper-thin sheets. Four sheets of leaf gelatin equal one package of powdered gelatin. Leaf gelatin must be soaked longer than granulated gelatin and is therefore not as popular. This product is often called for in jelled European dessert recipes. It can be found in some gourmet and bakery supply shops. Sweetened gelatin dessert mix is also available in various artificial fruit flavors.

A protein formed from collagen by boiling in water. Medically, gelatin is used as a hemostat, a plasma substitute, and a protein food adjunct in severe cases of malnutrition. Gelatin is used in the manufacture of capsules and suppositories. It is also used in the production of x-ray films as the medium for suspending the crystal salts on the surface of the acetate film.

For more information on gelatin, visit Britannica.com.

A jelly-like substance produced when tissues such as tendons and ligaments are boiled in water. Gelatin has been used as a source of dietary protein.

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.

Making Gelatin

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.

Medieval Beginnings

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.

Jell-O

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.

Bibliography

Wyman, Carolyn. JELL-O: A Biography, The History and Mystery of "America's Most Famous Dessert." San Diego, Calif., New York and London: Harcourt, 2001. Contains material on gelatin as well.

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

A substance obtained by partial hydrolysis of collagen derived from skin, white connective tissue, and bones of animals; used as a suspending agent for various drugs or in manufacture of capsules and suppositories; suggested for intravenous use as a plasma substitute, and has been used as an adjuvant protein food. In absorbable film and sponge, it is used in surgical procedures.

• g. digestion test — a tube test for the presence of fecal proteases; used in the diagnosis of exocrine pancreatic insufficiency.
• g. liquefaction test — a biochemical test used for the identification of several bacterial species. Detects the ability of the organism to produce substances which hydrolyze gelatin.
• g. sponge — a spongy form of denatured gelatin, soaked with thrombin and used as a hemostatic.
• zinc g. — a preparation of zinc oxide, gelatin, glycerin and purified water, applied topically as a protective.

For the dessert food, see Gelatin dessert.

Gelatin (from French gélatine) is a translucent, colorless, odorless, brittle, nearly tasteless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar way are called gelatinous. Gelatin is an irreversibly hydrolyzed form of collagen, and is classified as a foodstuff, with E number E441. It is found in some "gummy" candies as well as other products such as marshmallows, Jell-O, and some low-fat yogurt. Some dietary or religious customs forbid the use of gelatin from certain animal sources, and medical issues may limit or prevent its consumption by certain people.

Gelatin is a protein produced by partial hydrolysis of collagen extracted from the bones, connective tissues, organs and some intestines of animals such as domesticated cattle, pigs, and horses. The natural molecular bonds between individual collagen strands are broken down into a form that rearranges more easily. Gelatin melts to a liquid when heated and solidifies when cooled again. Together with water, it forms a semi-solid colloid gel. Gelatin forms a solution of high viscosity in water, which sets to a gel on cooling, and its chemical composition is, in many respects, closely similar to that of its parent collagen.^[1] Gelatin solutions show viscoelastic flow and streaming birefringence. If gelatin is put into contact with cold water, some of the material dissolves. The solubility of the gelatin is determined by the method of manufacture. Typically, gelatin can be dispersed in a relatively concentrated acid. Such dispersions are stable for 10–15 days with little or no chemical changes and are suitable for coating purposes or for extrusion into a precipitating bath. Gelatin is also soluble in most polar solvents. Gelatin gels exist over only a small temperature range, the upper limit being the melting point of the gel, which depends on gelatin grade and concentration and the lower limit, the ice point at which ice crystallizes. The mechanical properties are very sensitive to temperature variations, previous thermal history of the gel, and time. The viscosity of the gelatin/water mixture increases with concentration and when kept cool (≈ 4 °C).

Contents 1 Production 1.1 Pretreatments 1.2 Extraction 1.3 Recovery 2 Edible gelatins 3 Uses 3.1 Technical uses 3.2 Other uses 4 Religion and gelatin substitutes 5 Medical and nutritional properties 6 Safety concerns 7 References

Production

The worldwide production amount of gelatin is about 300,000 tons per year (roughly 600 million lb) ^[2]. On a commercial scale, gelatin is made from by-products of the meat and leather industry. Recently, fish by-products have also been considered because they eliminate some of the religious obstacles surrounding gelatin consumption ^[3].

Gelatin is derived mainly from pork skins, pork and cattle bones, or split cattle hides; contrary to popular belief, horns and hooves are not used.^[4] The raw materials are prepared by different curing, acid, and alkali processes which are employied to extract the dried collagen hydrolysate. These processes ^[5] may take up to several weeks, and differences in such processes have great effects on the properties of the final gelatin products ^[6].

Gelatin can also be prepared at home. Boiling certain cartilaginous cuts of meat or bones will result in gelatin being dissolved into the water. Depending on the concentration, the resulting broth, when cooled, will naturally form a jelly or gel. This process, for instance, may be used for the pot-au-feu dish.

While there are many processes whereby collagen can be converted to gelatin, they all have several factors in common. The intermolecular and intramolecular bonds which stabilize insoluble collagen rendering it insoluble must be broken, and the hydrogen bonds which stabilize the collagen helix must also be broken ^[1]. The manufacturing processes of gelatin consists of three main stages:

1. Pretreatments to make the raw materials ready for the main extraction step and to remove impurities which may have negative effects on physicochemical properties of the final gelatin product,
2. The main extraction step, which is usually done with hot water or dilute acid solutions as a multistage extraction to hydrolyze collagen into gelatin, and finally,
3. The refining and recovering treatments including filtration, clarification, evaporation, sterilization, drying, rutting, grinding, and sifting to remove the water from the gelatin solution, to blend the gelatin extracted, and to obtain dried, blended and ground final gelatin.

Pretreatments

If the physical material which will be used in production is bones, dilute acid solutions should be used to remove calcium and similar salts. Hot water or several solvents may be used for degreasing. Maximum fat content of the material should not exceed 1% before the main extraction step. If the raw material is hides and skin, size reduction, washing, removing hair from the hides, and degreasing are the most important pretreatments used to make the hides and skins ready for the main extraction step. Raw material preparation for extraction is done by three different methods: acid, alkali, and enzymatic treatments. Acid treatment is especially suitable for less fully crosslinked materials such as pig skin collagen. Pig skin collagen is less complex than the collagen found in bovine hides. Acid treatment is faster than alkali treatment and requires normally 10 to 48 hours. Alkali treatment is suitable for more complex collagen, e.g., the collagen found in bovine hides. This process requires longer time, normally several weeks. The purpose of the alkali treatment is to destroy certain chemical crosslinkages still present in collagen. The gelatin obtained from acid treated raw material has been called type-A gelatin, and the gelatin obtained from alkali treated raw material is referred to as type-B gelatin. Enzymatic treatments used for preparing raw material for the main extraction step are relatively new. Enzymatic treatments have some advantages in contrast to alkali treatment. Time required for enzymatic treatment is short, the yield is almost 100% in enzymatic treatment, the purity is also higher, and the physical properties of the final gelatin product are better.

Extraction

After preparation of the raw material, i.e., reducing crosslinkages between collagen components and removing some of the impurities such as fat and salts, partially purified collagen is converted into gelatin by extraction with either water or acid solutions at appropriate temperatures. This extraction is one of the most important steps in gelatin production, it enables the experimentor to thoroughly examine the specimens insides. All industrial processes are based on neutral or acid pH values because though alkali treatments speed up conversion, they also promote degradation processes. Acid extract conditions are extensively used in the industry but the degree of acid varies with different processes. This extraction step is a multi stage process, and the extraction temperature is usually increased in later extraction steps. This procedure ensures the minimum thermal degradation of the extracted gelatin.

Recovery

This process includes several steps such as filtration, evaporation, sterilization, drying, grinding, and sifting. These operations are concentration-dependent and also dependent on the particular gelatin used. Degradation must be avoided or minimized. For this purpose, limiting the temperature as much as possible would be helpful. Rapid processing is required for most of them. All of these processing steps should be done in several stages to avoid extensive deterioration of peptide structure. Otherwise, low gelling strength would be obtained that is not generally desired.

Edible gelatins

Household gelatin comes in the form of sheets, granules, or powder. Instant types can be added to the food as they are; others need to be soaked in water beforehand.

Uses

Probably best known as a gelling agent in cooking, different types and grades of gelatin are used in a wide range of food and non-food products:

Common examples of foods that contain gelatin are gelatin desserts, trifles, aspic, marshmallows, and confectioneries such as Peeps, gummy bears and jelly babies. Gelatin may be used as a stabilizer, thickener, or texturizer in foods such as jams, yoghurt, cream cheese, and margarine; it is used, as well, in fat-reduced foods to simulate the mouthfeel of fat and to create volume without adding calories.

Gelatin is used for the clarification of juices, such as apple juice, and of vinegar. Isinglass, from the swim bladders of fish, is still used as a fining agent for wine and beer.^[7] Beside hartshorn jelly, from deer antlers (hence the name "hartshorn"), isinglass was one of the oldest sources of gelatin. Gelatine was used for hardening paper in Colonial times.

Technical uses

Capsules made of gelatin.

• Certain professional lighting equipment uses color gels to change the beam color. These used to be made with gelatin, hence the term color gel.
• Gelatin typically constitutes the shells of pharmaceutical capsules in order to make them easier to swallow. Hypromellose is a vegan-acceptable alternative to gelatin, but is more expensive to produce.
• Animal glues such as hide glue are essentially unrefined gelatin.
• It is used to hold silver halide crystals in an emulsion in virtually all photographic films and photographic papers. Despite some efforts, no suitable substitutes with the stability and low cost of gelatin have been found.
• Used as a carrier, coating or separating agent for other substances; for example, it makes beta-carotene water-soluble thus imparting a yellow colour to any soft drinks containing beta-carotene.
• Gelatin is closely related to bone glue and is used as a binder in match heads and sandpaper.
• Cosmetics may contain a non-gelling variant of gelatin under the name hydrolyzed collagen.
• As a surface sizing, it smooths glossy printing papers or playing cards and maintains the wrinkles in crêpe paper.

Other uses

• Blocks of ballistic gelatin simulate muscle tissue as a standardized medium for testing firearms ammunition.
• Gelatin is used by synchronized swimmers to hold their hair in place during their routines as it will not dissolve in the cold water of the pool. It is frequently referred to as "knoxing," a reference to Knox brand gelatin.^[8]
• When added to boiling water and cooled, unflavored gelatin can make a home-made hair styling gel that is cheaper than many commercial hair styling products, but by comparison has a shorter shelf life (about a week) when stored in this form (usually in a refrigerator). After being applied to scalp hair, it can be removed with rinsing and some shampoo.
• It is commonly used as a biological substrate to culture adherent cells.
• Also used by those who are sensitive to tannins (which can irritate the stomach) in teas, soups or brews.
• It may be used as a medium with which to consume LSD. LSD in gelatin form is known as "windowpane" or "gel."
• Gelatin is used to make the shells of paintballs, similar to the way pharmaceutical capsules are produced.

Religion and gelatin substitutes

Special kinds of gelatin indicate the specific animal origin that was used for its production. For example, Muslim halal or Jewish kosher customs may require gelatin from sources other than pigs, from animals slaughtered ritually, or from fish. Hindu and Buddhist consumers may require animal product free alternatives. An alternative source of gelatin substitutes could be natural gel sources such as agar-agar (a seaweed), carrageenan, pectin, or konjak. A potential advantage over gelatin from pigs or cows is the absence of medical issues. However, alternative sources can be associated with health problems of their own (see for instance health concerns regarding carrageenan).

Medical and nutritional properties

Amino acid composition

Although gelatin is 98-99% protein by dry weight, it has less nutritional value than many other protein sources. Gelatin is unusually high in the non-essential amino acids glycine and proline, (i.e., those produced by the human body), while lacking certain essential amino acids (i.e., those not produced by the human body). It contains no tryptophan and is deficient in isoleucine, threonine, and methionine. The approximate amino acid composition of gelatin is: glycine 21%, proline 12%, hydroxyproline 12%, glutamic acid 10%, alanine 9%, arginine 8%, aspartic acid 6%, lysine 4%, serine 4%, leucine 3%, valine 2%, phenylalanine 2%, threonine 2%, isoleucine 1%,hydroxylysine 1%, methionine and histidine <1% and tyrosine <0.5%. These values vary, especially the minor constituents, depending on the source of the raw material and processing technique.^[9]

Eggs in aspic

Gelatin is one of the few foods that cause a net loss of protein if eaten exclusively. In the 1960s, several people died of malnutrition while on popular liquid protein diets.^[10]

For decades, gelatin has been touted as a good source of protein. It has also been said to strengthen nails and hair.^[11][12] The human body itself produces abundant amounts of the proteins found in gelatin.

Several Russian researchers offer the following opinion regarding certain peptides found in gelatin: "gelatin peptides reinforce resistance of the stomach mucous tunic to ethanol and stress action, decreasing the ulcer area by twice."^[13]

Gelatin has also been claimed to promote general joint health. A study at Ball State University, sponsored by Nabisco (the former parent company of Knox gelatin^[14], found that gelatin supplementation relieved knee joint pain and stiffness in athletes.^[15]

Safety concerns

Strict regulations apply for all steps in the gelatin manufacturing process. Gelatin is produced from natural raw materials which originate from animals that have been examined and accepted for human consumption by veterinary authorities. Hygienic regulations with respect to fresh raw materials are ensured and each batch of raw material delivered to the manufacturing plant is immediately checked and documented.

All reputable gelatin manufacturers today follow the Quality Management System according to ISO 9001 to comply with all required physical, chemical, microbiological and technical production and quality standards. In this way all process steps follow international laws and customer-specific quality parameters and are guaranteed and documented. For pharmaceutical grade gelatins strict regulations from the Food and Drug Administration (FDA), the European CPMP’s regulation and European Pharmacopoeia must be met. A detailed overview of the regulatory requirements for gelatin production can be found in the Gelatine Handbook, page 99-101 ^[16].

References

1. ^ ^{a b} Ward, A.G.; Courts, A. (1977). The Science and Technology of Gelatin. New York: Academic Press. 
2. ^ "Gelatine.org Market Data 2005". Gelatine Manufacturers of Europe. http://www.gelatine.org/en/gelatine/overview/127.htm. Retrieved 2006-12-04. 
3. ^ "What is Halal?". Islamic Services of America. http://www.isaiowa.org/content.asp?ID=1677. Retrieved 2006-12-04. 
4. ^ "Gelatine information, news, history and more". Gelatine Manufacturers Institute of America. http://www.gelatin-gmia.com/html/qanda.html. Retrieved 2008-09-26. 
5. ^ "Rousselot.com. Gelatin, Hydrolyzed collagen. Properties, processes, applications in the confectionnery, dairy, pharmaceutical industries". ROUSSELOT. http://www.rousselot.com. Retrieved 2008-07-15. 
6. ^ "Gelita.com". GELITA Group. http://www.gelita.com. Retrieved 2006-12-04. 
7. ^ "National Organic Standards Board Technical Advisory Panel Review: Gelatin processing" (PDF). http://www.omri.org/Gelatin-TAP.pdf. 
8. ^ "2008 United States Olympic Synchronized Swimming Team" (PDF). http://www.usasynchro.org/athletes/National/2008/Synchro_MediaGuide_2008.pdf. 
9. ^ Stevens, P.V. (1992). "Unknown". Food Australia 44 (7): 320–324. http://www.gelatin.co.za/gltn1.html. Retrieved 2005-08-11. 
10. ^ "What was wrong with those old "Liquid Protein" Diets". June 30, 2009. http://charm.cs.uiuc.edu/users/jyelon/lowcarb.med/topic9.html. 
11. ^ http://www.mysimon.com/Cosmetics/9000-10951_8-0.html?pagenum=9&orderby=2
12. ^ http://www.waningmoon.com/nails/faq.shtml
13. ^ "Gelatin Treats Ulcer". Medical News Today. August 22, 2006. http://www.medicalnewstoday.com/medicalnews.php?newsid=50126. 
14. ^ http://www.gelita.com
15. ^ Pearson, David. "Gelatin found to reduce joint pain in athletes". http://www.bsu.edu/news/article/0,1370,-1019-632,00.html. 
16. ^ Schrieber, R. and Gareis, H. (2007). Gelatine Handbook for dummies – Theory and Industrial Practice, Wiley-VCH Verlag GmbH & Co, Weinheim, Germany

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - gelatine

Français (French)
n. - gélatine

Deutsch (German)
n. - Gelatine

Ελληνική (Greek)
n. - (χημ.) ζωική κόλλα, ζελατίνη

Italiano (Italian)
gelatina

Português (Portuguese)
n. - gelatina (f)

Русский (Russian)
желатин

Español (Spanish)
n. - gelatina

Svenska (Swedish)
n. - gelatin

中文（简体）(Chinese (Simplified))
胶质, 白明胶

中文（繁體）(Chinese (Traditional))
n. - 膠質, 白明膠

한국어 (Korean)
n. - 젤라틴(아교)

日本語 (Japanese)
n. - ゼラチン

עברית (Hebrew)
n. - ‮חלבון חסר צבע וטעם המופק מקולאגאן ומשמש להכנת מזון, מקפית, ג'לטינה, ג'לטין‬

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