AskDefine | Define gelatinous

Dictionary Definition

gelatinous adj : thick like gelatin [syn: gelatinlike, jellylike]

User Contributed Dictionary

English

Adjective

gelatinous
  1. jelly-like
  2. of or referring to gelatin

Translations

jelly-like
of or referring to gelatin

Extensive Definition

Gelatin (also gelatine, from French gélatine) is a translucent, colourless, brittle, nearly tasteless solid substance, extracted from the collagen inside animals' connective tissue. It has been commonly used as an emulsifier in food, pharmaceutical, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar way are called gelatinous. Gelatin is an irreversibly hydrolyzed form of collagen. Gelatin is classified as a foodstuff and has E number 441.
Gelatin is a protein produced by partial hydrolysis of collagen extracted from the bones, connective tissues, organs, and some intestines of animals such as the domesticated cattle, and horses. The natural molecular bonds between individual collagen strands are broken down into a form that rearranges more easily. Gelatin melts 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. 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 (≈40°F).

Production

The worldwide production amount of gelatin is about 300,000 tons per year (roughly 600 million lbs.) . On a commercial scale, gelatin is made from by-products of the meat and leather industry, mainly pork skins, pork and cattle bones, or split cattle hides. Recently, by-products of the fishery industry began to be considered as raw material for gelatin production because they eliminate most of the religious obstacles surrounding gelatin consumption . Contrary to popular belief, horns and hooves are not commonly used. The raw materials are prepared by different curing, acid, and alkali processes which are employed to extract the dried collagen hydrolysate. These processes may take up to several weeks, and differences in such processes have great effects on the properties of the final gelatin products .
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 Beside hartshorn jelly, from deer antlers (hence the name "hartshorn"), isinglass was one of the oldest sources of gelatin.

Technical uses

  • Gelatin typically constitutes the shells of pharmaceutical capsules in order to make them easier to swallow. Hypromellose is the vegetarian counterpart 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, it, for example, 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. Though commonly used, the owners of the trademark object to the genericized use of the term.
  • 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".

Medicinal and nutritional properties

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.
Gelatin is one of the few foods that cause a net loss of protein if eaten exclusively. In the 1970s, several people died of malnutrition while on popular liquid protein diets.
For decades, gelatin has been touted as a good source of protein. It has also been said to strengthen nails and hair. http://www.mysimon.com/Cosmetics/9000-10951_8-0.html?pagenum=9&orderby=2 http://www.waningmoon.com/nails/faq.shtml} However, there is little scientific evidence to support such an assertion, one which may be traced back to Knox's revolutionary marketing techniques of the 1890s, when it was advertised that gelatin contains protein and that lack of protein causes dry, deformed nails. In fact, the human body itself produces abundant amounts of the proteins found in gelatin. Furthermore, dry nails are usually due to a lack of moisture, not protein.
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."
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 gelatinhttp://www.gelita.com/), found that gelatin supplementation relieved knee joint pain and stiffness in athletes. These results have not yet been replicated by other researchers.

Safety concerns

Due to bovine spongiform encephalopathy (BSE), also known as "mad cow disease", and its link to new variant Creutzfeldt-Jakob disease (vCJD), there has been much concern about using gelatin derived from possibly infected animal parts. One study released in 2004, however, demonstrated that the gelatin production process destroys most of the BSE prions that may be present in the raw material. However, more detailed recent studies regarding the safety of gelatin in respect to mad cow disease have prompted the U.S. Food and Drug Administration to re-issue a warning and stricter guidelines for the sourcing and processing of gelatin to reduce the potential risk posed by Bovine Spongiform Encephalopathy from 1997.
An alternative source for gelatin could be fish gelatin from for example cat fish, Tilapia species or Trachurus species. Other advantages over gelatin from pigs or cows is the absence of issues for preparing food because of religious reasons.

References

External links

Gelatin
gelatinous in Arabic: جيلاتين
gelatinous in Czech: Želatina
gelatinous in Danish: Gelatine
gelatinous in German: Gelatine
gelatinous in Spanish: Gelatina
gelatinous in Esperanto: Gelateno
gelatinous in French: Gélatine
gelatinous in Indonesian: Gelatin
gelatinous in Italian: Gelatina animale
gelatinous in Hebrew: ג'לטין
gelatinous in Hungarian: Zselatin
gelatinous in Dutch: Gelatine
gelatinous in Japanese: ゼラチン
gelatinous in Norwegian: Gelatin
gelatinous in Polish: Żelatyna
gelatinous in Portuguese: Gelatina
gelatinous in Romanian: Gelatină
gelatinous in Russian: Желатин
gelatinous in Slovenian: Želatina
gelatinous in Finnish: Liivate
gelatinous in Swedish: Gelatin
gelatinous in Thai: เจลาติน
gelatinous in Turkish: Jelatin
gelatinous in Chinese: 明膠

Synonyms, Antonyms and Related Words

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