Editing Gelatin

{{short description|Mixture of peptides and proteins derived from connective tissues of animals}}
{{for-multi|the dessert food|Gelatin dessert|the gel based on starch|Starch gelatinization|other uses}}
{{Use dmy dates|date=April 2020}}
[[File:Gelatine.png|thumb|right|Sheet (or leaf) gelatin for cooking]]

'''Gelatin''' or '''gelatine''' ({{etymology|la|{{Wikt-lang|la|gelatus}}|stiff, frozen}}) is a translucent, colorless, flavorless food ingredient, commonly derived from [[collagen]] taken from animal body parts. It is brittle when dry and rubbery when moist. It may also be referred to as [[hydrolysis|hydrolyzed]] collagen, collagen [[hydrolysate]], gelatine hydrolysate, hydrolyzed gelatine, and collagen [[peptide]]s after it has undergone hydrolysis. It is commonly used as a [[gelling agent]] in food, beverages, [[medication]]s, drug or vitamin [[capsule (pharmacy)|capsules]], [[photographic film]]s, [[photographic paper|papers]], and [[cosmetics]].

Substances containing gelatin or functioning in a similar way are called '''gelatinous substances'''. Gelatin is an irreversibly [[hydrolysis|hydrolyzed]] form of collagen, wherein the hydrolysis reduces [[protein]] fibrils into smaller [[peptide]]s; depending on the physical and chemical methods of denaturation, the molecular weight of the peptides falls within a broad range. Gelatin is present in [[gelatin dessert]]s, most [[gummy candy]] and [[marshmallow]]s, [[ice cream]]s, [[dip (food)|dips]], and [[yogurt]]s.<ref name="gelatin">{{cite journal |author=Kodjo Boady Djagnya |author2=Zhang Wang |author3= Shiying Xu |title=Gelatin: A Valuable Protein for Food and Pharmaceutical Industries: Review |journal=Critical Reviews in Food Science and Nutrition |volume=41 |issue=6 |pages=481–92 |year=2010 |doi=10.1080/20014091091904 |pmid=11592686|s2cid=37668312 }}</ref> Gelatin for cooking comes as powder, granules, and sheets. Instant types can be added to the food as they are; others must soak in water beforehand.

Gelatin is a natural polymer derived from collagen through hydrolysis. Its chemical structure is primarily composed of amino acids, including glycine, proline, and hydroxyproline. These amino acid chains form a three-dimensional network through hydrogen bonding and hydrophobic interactions, giving gelatin its gelling properties. Gelatin dissolves well in water and can form reversible gel-like substances. When cooled, water is trapped within its network structure, resulting in what is known as a hydrogel.

As a hydrogel, gelatin's uniqueness lies in its ability to maintain a stable structure and function even when it contains up to 90% water. This makes gelatin widely used in medical, food, and cosmetic industries, especially in drug delivery systems and wound dressings, as it provides stable hydration and promotes the healing process.<ref>{{Cite journal |last=Sasayama |first=Yumi |last2=Hasegawa |first2=Maki |last3=Taguchi |first3=Eri |last4=Kubota |first4=Kohei |last5=Kuboyama |first5=Takeshi |last6=Naoi |first6=Tomoyuki |last7=Yabuuchi |first7=Hayato |last8=Shimai |first8=Norie |last9=Asano |first9=Miyoko |last10=Tokunaga |first10=Akihiro |last11=Ishii |first11=Toshihiko |last12=Enokizono |first12=Junichi |date=October 2019 |title=In vivo activation of PEGylated long circulating lipid nanoparticle to achieve efficient siRNA delivery and target gene knock down in solid tumors |url=https://linkinghub.elsevier.com/retrieve/pii/S0168365919305371 |journal=Journal of Controlled Release |language=en |volume=311-312 |pages=245–256 |doi=10.1016/j.jconrel.2019.09.004}}</ref> Moreover, its biodegradability and biocompatibility make it an ideal hydrogel material.<ref>{{Cite journal |last=Li |first=Manlin |last2=Zhang |first2=Zengqiang |last3=Li |first3=Ronghua |last4=Wang |first4=Jim J. |last5=Ali |first5=Amjad |date=May 2016 |title=Removal of Pb(II) and Cd(II) ions from aqueous solution by thiosemicarbazide modified chitosan |url=https://linkinghub.elsevier.com/retrieve/pii/S014181301630160X |journal=International Journal of Biological Macromolecules |language=en |volume=86 |pages=876–884 |doi=10.1016/j.ijbiomac.2016.02.027}}</ref>

== Characteristics ==

=== Properties ===
Gelatin is a collection of peptides and [[protein]]s produced by partial [[hydrolysis]] of collagen extracted from the skin, bones, and [[connective tissue]]s of animals such as domesticated cattle, chicken, pigs, and fish. During hydrolysis, some of the bonds between and within component proteins are broken. Its chemical composition is, in many aspects, closely similar to that of its parent collagen.<ref name="Ward2">{{cite book|last=Ward|first=A.G.|title=The Science and Technology of Gelatin|author2=Courts, A.|publisher=Academic Press|year=1977|isbn=978-0-12-735050-9|location=New York}}</ref> Photographic and pharmaceutical grades of gelatin generally are sourced from cattle bones and pig skin. Gelatin is classified as a [[hydrogel]].

[[File:Amino_Acid_Composition_in_Gelatin_chart.png|right|thumb|[[Amino acid]] composition]]
Gelatin is nearly tasteless and odorless with a colorless or slightly yellow appearance.<ref name=":02">Budavari, S. (1996). ''Merck Index, (12th ed.)'' Whitehouse Station, NJ: Merck.</ref><ref>Food and Nutrition Board, National Academy of Sciences. (1996). ''Food Chemicals Codex 4th Ed''. Washington, DC: National Academy Press.</ref> It is transparent and brittle, and it can come as sheets, flakes, or as a powder.<ref name=":02" /> [[Polar solvent]]s like hot water, glycerol, and acetic acid can dissolve gelatin, but it is insoluble in organic solvents like alcohol.<ref name=":02" /> Gelatin absorbs 5–10 times its weight in water to form a gel.<ref name=":02" /> The gel formed by gelatin can be melted by reheating, and it has an increasing viscosity under stress ([[Thixotropy|thixotropic]]).<ref name=":02" /> The upper melting point of gelatin is below [[human body temperature]], a factor that is important for [[mouthfeel]] of foods produced with gelatin.<ref name="Cole2">{{cite book|title=Encyclopedia of Food Science and Technology|date=2000|publisher=John Wiley & Sons|isbn=978-0-471-19255-8|editor=Francis, Frederick J.|edition=2nd|pages=1183–88|chapter=Gelatin|chapter-url=http://www.gelatin.co.za/gltn1.html|archive-url=https://web.archive.org/web/20050829055205/http://www.gelatin.co.za/gltn1.html|archive-date=29 August 2005|url-status=live|df=dmy-all}}</ref> The [[viscosity]] of the gelatin-water mixture is greatest when the gelatin concentration is high and the mixture is kept cool at about {{convert|4|C}}. Commercial gelatin will have a gel strength of around 90 to 300 grams Bloom using the [[Bloom (test)|Bloom]] test of gel strength.<ref>Igoe, R.S. (1983). ''Dictionary of Food Ingredients.'' New York: Van Nostrand Reinhold.</ref> Gelatin's strength (but not viscosity) declines if it is subjected to temperatures above {{convert|100|C}}, or if it is held at temperatures near 100&nbsp;°C for an extended period of time.<ref>{{Cite web |title=6 Unexpected Factors That Can Ruin Your Gelatin Desserts |url=https://www.seriouseats.com/how-to-avoid-problems-with-gelatin-dessert-baking |first1=Stella |last1=Parks |website=Serious Eats |language=en}}</ref><ref>[https://web.archive.org/web/20170509225608/http://www.finecooking.com/article/the-science-of-gelatin The Science of Gelatin – FineCooking]</ref>

Gelatins have diverse melting points and gelation temperatures, depending on the source. For example, gelatin derived from fish has a lower melting and gelation point than gelatin derived from beef or pork.<ref name="omri3">{{cite web|title=National Organic Standards Board Technical Advisory Panel Review: Gelatin processing|url=http://www.omri.org/Gelatin-TAP.pdf|archive-url=https://web.archive.org/web/20070927014944/http://www.omri.org/Gelatin-TAP.pdf|archive-date=27 September 2007|work=omri.org|df=dmy}}</ref>

=== Composition ===
When dry, gelatin consists of 98–99% protein, but it is not a nutritionally complete protein since it is missing [[tryptophan]] and is deficient in [[isoleucine]], [[threonine]], and [[methionine]].<ref>Potter, N.N. and J.H. Hotchkiss. (1998). ''Food Science (5th ed.)'' Gaithersburg, MD: Aspen.{{page needed|date=November 2024}}</ref>{{page needed|date=November 2024}} The [[amino acid]] content of hydrolyzed collagen is the same as collagen. Hydrolyzed collagen contains 19 amino acids, predominantly [[glycine]] (Gly) 26–34%, [[proline]] (Pro) 10–18%, and [[hydroxyproline]] (Hyp) 7–15%, which together represent around 50% of the total amino acid content.<ref name=":12">Poppe, J. (1997). Gelatin, in A. Imeson (ed.) ''Thickening and Gelling Agents for Food (2nd ed.)'': 144–68. London: Blackie Academic and Professional.</ref> Glycine is responsible for close packing of the chains. Presence of proline restricts the conformation. This is important for gelation properties of gelatin.<ref>{{cite web|title=Gelatin Handbook|url=http://www.gelatin-gmia.com/images/GMIA_Gelatin_Manual_2012.pdf|archive-url=https://web.archive.org/web/20170516200308/http://www.gelatin-gmia.com/images/GMIA_Gelatin_Manual_2012.pdf|archive-date=16 May 2017|access-date=27 September 2017|df=dmy-all}}</ref> Other amino acids that contribute highly include: [[alanine]] (Ala) 8–11%; [[arginine]] (Arg) 8–9%; [[aspartic acid]] (Asp) 6–7%; and [[glutamic acid]] (Glu) 10–12%.<ref name=":12" />

== Research ==
In 2011, the [[European Food Safety Authority]] Panel on Dietetic Products, Nutrition and Allergies concluded that "a [[causality|cause and effect relationship]] has not been established between the consumption of collagen hydrolysate and maintenance of joints".<ref name="EFSA">{{Cite journal |author=EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)|doi = 10.2903/j.efsa.2011.2291|title = Scientific Opinion on the substantiation of a health claim related to collagen hydrolysate and maintenance of joints pursuant to Article 13(5) of Regulation (EC) No 1924/2006|journal = EFSA Journal|year = 2011|volume = 9|issue = 7|doi-access = free}}</ref>

Hydrolyzed collagen has been investigated as a type of wound dressing aimed at correcting imbalances in the wound microenvironment and the treatment of refractory wounds (chronic wounds that do not respond to normal treatment), as well as deep second-degree burn wounds.<ref>{{Cite journal |last1=Ge |first1=Baosheng |last2=Wang |first2=Haonan |last3=Li |first3=Jie |last4=Liu |first4=Hengheng |last5=Yin |first5=Yonghao |last6=Zhang |first6=Naili |last7=Qin |first7=Song |date=2020-03-25 |title=Comprehensive Assessment of Nile Tilapia Skin (Oreochromis niloticus) Collagen Hydrogels for Wound Dressings |journal=Marine Drugs |volume=18 |issue=4 |pages=178 |doi=10.3390/md18040178 |doi-access=free |issn=1660-3397 |pmc=7230254 |pmid=32218368}}</ref><ref>{{Cite journal |last1=Fleck |first1=Cynthia Ann |last2=Simman |first2=Richard |date=2011-08-01 |title=Modern Collagen Wound Dressings: Function and Purpose |journal=The Journal of the American College of Certified Wound Specialists |volume=2 |issue=3 |pages=50–54 |doi=10.1016/j.jcws.2010.12.003 |issn=1876-4983 |pmc=3601889 |pmid=24527149}}</ref>

=== Safety concerns ===
Hydrolyzed collagen, like gelatin, is made from animal [[by-products]] from the [[meat industry]] or sometimes animal carcasses removed and cleared by [[knacker]]s, including skin, bones, and connective tissue.

In 1997, the U.S. [[Food and Drug Administration]] (FDA), with support from the TSE ([[transmissible spongiform encephalopathy]]) Advisory Committee, began monitoring the potential risk of transmitting animal diseases, especially [[bovine spongiform encephalopathy]] (BSE), commonly known as ''mad cow disease''.<ref>{{Cite web|url=https://www.fda.gov/ohrms/dockets/ac/97/transcpt/3283t2.pdf|title=Transmissible Spongiform Encephalopathies Advisory Committee (CJDSAC) Meeting Start Date – 23-APR-97|website=[[Food and Drug Administration]]|url-status=live|archive-url=https://wayback.archive-it.org/7993/20170404132502/https://www.fda.gov/ohrms/dockets/ac/97/transcpt/3283t2.pdf|archive-date=2017-04-04}}</ref> An FDA study from that year stated: "... steps such as heat, alkaline treatment, and filtration could be effective in reducing the level of contaminating TSE agents; however, scientific evidence is insufficient at this time to demonstrate that these treatments would effectively remove the BSE infectious agent if present in the source material."<ref>{{cite web|url=https://www.fda.gov/RegulatoryInformation/Guidances/ucm125182.htm|title=The Sourcing and Processing of Gelatin to Reduce the Potential Risk Posed by Bovine Spongiform Encephalopathy (BSE) in FDA-Regulated Products for Human Use|author=U.S. Food and Drug Administration|website=[[Food and Drug Administration]]|url-status=live|archive-url=https://web.archive.org/web/20170121080011/https://www.fda.gov/RegulatoryInformation/Guidances/ucm125182.htm|archive-date=21 January 2017|df=dmy-all}}</ref> On 18 March 2016, the FDA finalized three previously issued interim final rules designed to further reduce the potential risk of BSE in human food.<ref name="FDAFinalRule">{{cite web |url=https://www.federalregister.gov/documents/2016/03/18/2016-06123/use-of-materials-derived-from-cattle-in-human-food-and-cosmetics |title=Federal Register :: Use of Materials Derived From Cattle in Human Food and Cosmetics |author=Food and Drug Administration |date=March 18, 2016 |website=Federal Register, The Daily Journal of the United States Government |access-date=May 24, 2017 |url-status=live |archive-url=https://web.archive.org/web/20170603230919/https://www.federalregister.gov/documents/2016/03/18/2016-06123/use-of-materials-derived-from-cattle-in-human-food-and-cosmetics |archive-date=3 June 2017 |df=dmy-all}}</ref> The final rule clarified that "gelatin is not considered a prohibited cattle material if it is manufactured using the customary industry processes specified."<ref name="FDAConstituentUpdate">{{cite web |url=https://www.fda.gov/food/newsevents/constituentupdates/ucm490542.htm |title=FDA Announces Final Rule on Bovine Spongiform Encephalopathy |author=U.S. Food and Drug Administration |website=[[Food and Drug Administration]] |date=March 17, 2016 |access-date=May 24, 2017 |quote=Finally, the rule provides a definition of gelatin and clarifies that gelatin is not considered a prohibited cattle material if it is manufactured using the customary industry processes specified. Gelatin was never considered a prohibited cattle material, but FDA had never specifically defined gelatin in past IFRs. |url-status=live |archive-url=https://web.archive.org/web/20170430190647/https://www.fda.gov/Food/NewsEvents/ConstituentUpdates/ucm490542.htm |archive-date=30 April 2017 |df=dmy-all}}</ref>

The Scientific Steering Committee (SSC) of the [[European Union]] in 2003 stated that the risk associated with bovine bone gelatin is very low or zero.<ref>{{cite web|url=http://ec.europa.eu/food/fs/sc/ssc/out321_en.pdf|title=Updated Opinion On The Safety With Regard To TSE Risks Of Gelatine Derived From Ruminant Bones or Hides|author=Scientific Steering Committee, European Union|date=6–7 March 2003|archive-url=https://web.archive.org/web/20121026005256/http://ec.europa.eu/food/fs/sc/ssc/out321_en.pdf|archive-date=26 October 2012|df=dmy-all}}</ref><ref>{{cite web|url=https://www.fda.gov/OHRMS/DOCKETS/AC/03/briefing/3969B1_1d.pdf|title=The Removal and Inactivation of Potential TSE Infectivity by the Different Gelatin Manufacturing Processes|author=Gelatine Manufacturers of Europe (GME)|website=[[Food and Drug Administration]]|date=June 2003|url-status=live|archive-url=https://web.archive.org/web/20120114180148/https://www.fda.gov/OHRMS/DOCKETS/AC/03/briefing/3969B1_1d.pdf|archive-date=14 January 2012|df=dmy-all}}</ref>

In 2006, the [[European Food Safety Authority]] stated that the SSC opinion was confirmed, that the BSE risk of bone-derived gelatin was small, and that it recommended removal of the 2003 request to exclude the skull, brain, and [[vertebra]]e of bovine origin older than 12 months from the material used in gelatin manufacturing.<ref>{{cite journal|author=Scientific Panel on Biological Hazards of the European Food Safety Authority (EFSA) |title=Quantitative assessment of the human BSE risk posed by gelatine with respect to residual BSE risk |year=2006|journal=EFSA Journal|volume=312|pages=1–29|doi=10.2903/j.efsa.2006.312 |doi-access=}}</ref>

==Production==
[[File:Materials Used in Gelatin Production.svg|280px|thumb|{{Citation needed|date=December 2017}}]]
In 2019, the worldwide demand of gelatin was about {{convert|620000|tonne|e9lb|lk=in|abbr=}}.<ref>{{Cite web|title=Gelatin Market Size, Analysis {{!}} Industry Trends Report, 2020-2027|url=https://www.grandviewresearch.com/industry-analysis/gelatin-market-analysis|access-date=2020-10-17|website=www.grandviewresearch.com|language=en}}</ref> On a commercial scale, gelatin is made from [[by-product]]s of the [[meat]] and [[leather]] industries.
Most gelatin is derived from pork skins, pork and cattle bones, or split cattle hides.<ref name="gc">{{cite web|date=12 June 2013|title=Natural Health Products Ingredients Database: Hydrolyzed Collagen|url=http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq.do?atid=hydrolized.collagen|url-status=live|archive-url=https://web.archive.org/web/20160512222007/http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq.do?atid=hydrolized.collagen|archive-date=12 May 2016|access-date=9 May 2016|publisher=Government of Canada, Health Canada, Health Products and Food Branch, Natural Health Products Directorate|df=dmy-all}}</ref> Gelatin made from fish by-products avoids some of the religious objections to gelatin consumption.<ref name="Cole2" /> The raw materials are prepared by different curing, acid, and alkali processes that are employed to extract the dried collagen hydrolysate. These processes may take several weeks, and differences in such processes have great effects on the properties of the final gelatin products.

Gelatin also can be prepared at home. Boiling certain cartilaginous cuts of meat or bones results in gelatin being dissolved into the water. Depending on the concentration, the resulting stock (when cooled) will form a jelly or gel naturally. This process is used for [[aspic]].

While many processes exist whereby collagen may be converted to gelatin, they all have several factors in common. The intermolecular and intramolecular bonds that stabilize insoluble collagen must be broken, and also, the hydrogen bonds that stabilize the collagen [[helix]] must be broken.<ref name="Ward2" /> The manufacturing processes of gelatin consists of several main stages:
# Pretreatments to make the raw materials ready for the main extraction step and to remove impurities that may have negative effects on physicochemical properties of the final gelatin product.
# [[Hydrolysis]] of collagen into gelatin.
# Extraction of gelatin from the hydrolysis mixture, which usually is done with hot water or dilute acid solutions as a multistage process.
# 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, ground final product.

===Pretreatments===
If the raw material used in the production of the gelatin is derived from [[bone]]s, dilute [[acid]] solutions are used to remove [[calcium]] and other salts. Hot water or several solvents may be used to reduce the fat content, which should not exceed 1% before the main extraction step. If the raw material consists of [[hide (skin)|hides]] and skin, then size reduction, washing, hair removal, and degreasing are necessary to prepare the materials for the hydrolysis step.

===Hydrolysis===
After preparation of the raw material, i.e., removing some of the impurities such as fat and salts, partially purified collagen is converted into gelatin through hydrolysis. Collagen hydrolysis is performed by one of three different methods: [[acid hydrolysis|acid]]-, [[base hydrolysis|alkali]]-, and [[enzymatic hydrolysis]]. Acid treatment is especially suitable for less fully [[cross-link]]ed materials such as pig skin collagen and normally requires 10 to 48 hours. Alkali treatment is suitable for more complex collagen such as that found in [[bovine]] hides and requires more time, normally several weeks. The purpose of the alkali treatment is to destroy certain chemical crosslinks still present in collagen. Within the gelatin industry, 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.<ref>{{cite web|url= http://www.vyse.com/about_gelatin_process.html|title= Type A & B Process Definition|date= 26 October 2009|access-date= 16 July 2014|publisher= Vyse Gelatin Company|archive-url= https://web.archive.org/web/20150301224019/http://www.vyse.com/about_gelatin_process.html|archive-date= 1 March 2015|df= dmy-all}}</ref>

Advances are occurring to optimize the yield of gelatin using enzymatic hydrolysis of collagen. The treatment time is shorter than that required for alkali treatment, and results in almost complete conversion to the pure product. The physical properties of the final gelatin product are considered better.<ref>{{cite journal|title=Recent advances on the role of process variables affecting gelatin yield and characteristics with special reference to enzymatic extraction: A review|journal=Food Hydrocolloids|date=February 2017|volume=63|pages=85–96|doi=10.1016/j.foodhyd.2016.08.007|last1=Ahmad|first1=Tanbir|last2=Ismail|first2=Amin|last3=Ahmad|first3=Siti Aqlima|last4=Khalil|first4=Khalilah A.|last5=Kumar|first5=Yogesh|last6=Adeyemi|first6=Kazeem D.|last7=Sazili|first7=Awis Q.}}</ref>

===Extraction===
Extraction is performed with either water or acid solutions at appropriate temperatures. All industrial processes are based on neutral or acid pH values because although alkali treatments speed up conversion, they also promote degradation processes. Acidic extraction conditions are extensively used in the industry, but the degree of acid varies with different processes. This extraction step is a multistage process, and the extraction temperature usually is increased in later extraction steps, which ensures minimum thermal degradation of the extracted gelatin.

===Recovery===
This process includes several steps such as filtration, evaporation, drying, grinding, and sifting. These operations are concentration-dependent and also dependent on the particular gelatin used. Gelatin degradation should be avoided and minimized, so the lowest temperature possible is used for the recovery process. Most recoveries are rapid, with all of the processes being done in several stages to avoid extensive deterioration of the peptide structure. A deteriorated peptide structure would result in a low gel strength, which is not generally desired.

==Uses==

===Early history of food applications===
The 10th-century ''[[Ibn Sayyar al-Warraq|Kitab al-Tabikh]]'' includes a recipe for a fish aspic, made by boiling fish heads.<ref>{{cite book |last=Nasrallah |first=Nawal |title=Annals of the Caliphs' Kitchens |publisher=Brill |date=2007|isbn=9789004158672}}{{page needed|date=May 2024}}</ref>{{page needed|date=May 2024}}

A recipe for jelled meat broth is found in ''[[Le Viandier]]'', written in or around 1375.<ref>{{Cite book|last= Scully|first=Terence|title=The viandier of Taillevent: an edition of all extant manuscripts|publisher=University of Ottawa Press|date=January 1, 1988|location=Ottawa, Ontario|page=270|isbn=978-0-7766-0174-8}}</ref>

In 15th century Britain, cattle hooves were boiled to produce a gel.<ref name="enc">{{cite encyclopedia |url=http://www.encyclopedia.com/topic/gelatin.aspx |title=Gelatin |encyclopedia=Encyclopedia.com |date=2016 |access-date=9 September 2016 |url-status=live |archive-url=https://web.archive.org/web/20160917110428/http://www.encyclopedia.com/topic/gelatin.aspx |archive-date=17 September 2016 |df=dmy-all}}</ref> By the late 17th century, the French inventor [[Denis Papin]] had discovered another method of gelatin extraction via boiling of bones.<ref name="RHP">{{cite journal |last1=Viel |first1=Claude |last2=Fournier |first2=Josette |title=Histoire des procédés d'extraction de la gélatine et débats des commissions académiques (XIXe siècle) |journal=Revue d'Histoire de la Pharmacie |date=2006 |volume=54 |issue=349 |pages=7–28 |doi=10.3406/pharm.2006.5939 |pmid=17152838 |url=https://www.persee.fr/doc/pharm_0035-2349_2006_num_94_349_5939 |access-date=2 January 2020 |trans-title=History of gelatin extraction processes and debates of academic commissions |language=fr}}</ref> An English patent for gelatin production was granted in 1754.<ref name="enc"/> In 1812, the chemist {{ill|Jean-Pierre-Joseph d'Arcet|fr}} further experimented with the use of [[hydrochloric acid]] to extract gelatin from bones, and later with steam extraction, which was much more efficient. The French government viewed gelatin as a potential source of cheap, accessible protein for the poor, particularly in Paris.<ref name="davis">{{cite book |last1=Davis |first1=Jennifer J. |title=Defining Culinary Authority: The Transformation of Cooking in France, 1650–1830. |date=2013 |publisher=Louisiana State University Press}}</ref>

Food applications in France and the United States during the 19th century appear to have established the versatility of gelatin, including the origin of its popularity in the US as [[Jell-O]].<ref>{{cite book|isbn=978-0-7567-8854-4|title=Jell-o: A Biography: the History And Mystery of America's Most Famous Dessert|author=Wyman, Carolyn|publisher=Diane Publishing Company|year=2001}}</ref> In the mid-19th century, the American industrialist and inventor, [[Peter Cooper]], registered a patent for a gelatin dessert powder he called "Portable Gelatin", which only needed the addition of water. In the late 19th century, Charles and [[Rose Knox]] set up the Charles B. Knox Gelatin Company in New York, which promoted and popularized the use of gelatin.<ref name="enc2">{{cite encyclopedia |url=http://www.encyclopedia.com/topic/gelatin.aspx#2 |title=Gelatin: background |encyclopedia=Encyclopedia.com |date=2016 |access-date=9 September 2016 |url-status=live |archive-url=https://web.archive.org/web/20160917110428/http://www.encyclopedia.com/topic/gelatin.aspx#2 |archive-date=17 September 2016 |df=dmy-all}}</ref>

===Culinary uses===
[[File:Oeufs en gelée p1150406.jpg|thumb|[[Egg (food)|Eggs]] in [[aspic]]]]
[[File:Congealed gelatin of boiled fish (Japanese Spanish mackerel).JPG|thumb|[[Freezing|Congealed into jelly]] gelatin of boiled fish with [[soy sauce]] and kept around at 8&nbsp;°C. In Japan, it is called [[:ja:煮凝り|煮凝り]] (''Niko-gori''), literally 'boiled then become [[:en:Flocculation|flocculated]]/stiffened'. Not intended cooking, occurs naturally in winter, historically tasted.]]

Probably best known as a [[gelling agent]] in [[cooking]], different types and grades of gelatin are used in a wide range of food and nonfood products. Common examples of foods that contain gelatin are [[gelatin dessert]]s, [[trifle]]s, [[aspic]], [[marshmallow]]s, [[candy corn]], and confections such as [[Peeps]], [[gummy bear]]s, [[fruit snack]]s, and [[jelly baby|jelly babies]].<ref>{{Cite web|last=Nene|first=Chhaya|date=2018-03-09|title=Six Popular Foods You Didn't Know Had Gelatin|url=https://medium.com/@chhayasnene/six-popular-foods-you-didnt-know-had-gelatin-43b6fecfbe76|access-date=2020-08-13|website=Medium|language=en}}</ref> Gelatin may be used as a [[stabilizer (food)|stabilizer]], thickener, or texturizer in foods such as yogurt, [[cream cheese]], and [[margarine]]; it is used, as well, in fat-reduced foods to simulate the [[mouthfeel]] of fat and to create volume. It also is used in the production of several types of Chinese soup dumplings, specifically Shanghainese soup dumplings, or ''[[xiaolongbao]]'', as well as ''[[Shengjian mantou]]'', a type of fried and steamed dumpling. The fillings of both are made by combining ground pork with gelatin cubes, and in the process of cooking, the gelatin melts, creating a soupy interior with a characteristic gelatinous stickiness.

Gelatin is used for the clarification of juices, such as apple juice, and of vinegar.<ref>Organic Materials Review Institute for the USDA National Organic Program. (2002). "Gelatin: Processing." ''National Organic Standards Board Technical Advisory Panel Review.'' https://www.ams.usda.gov/sites/default/files/media/Gelatin%20Fish%20TR%20Review.pdf</ref>

[[Isinglass]] is obtained from the swim bladders of fish. It is used as a fining agent for wine and beer.<ref name="omri">{{cite web|title=National Organic Standards Board Technical Advisory Panel Review: Gelatin processing |url=http://www.omri.org/Gelatin-TAP.pdf |work=omri.org |archive-url=https://web.archive.org/web/20070927014944/http://www.omri.org/Gelatin-TAP.pdf |archive-date=27 September 2007 |df=dmy}}</ref> Besides [[hartshorn]] jelly, from deer antlers (hence the name "hartshorn"), isinglass was one of the oldest sources of gelatin.

=== Cosmetics ===
In cosmetics, hydrolyzed collagen may be found in topical creams, acting as a product texture conditioner, and moisturizer. Collagen implants or dermal fillers are also used to address the appearance of wrinkles, contour deficiencies, and acne scars, among others. The U.S. Food and Drug Administration has approved its use, and identifies cow (bovine) and human cells as the sources of these fillers. According to the FDA, the desired effects can last for 3–4 months, which is relatively the most short-lived compared to other materials used for the same purpose.<ref>{{Cite journal|last=Health|first=Center for Devices and Radiological|date=2019-06-13|title=Dermal Fillers Approved by the Center for Devices and Radiological Health|url=https://www.fda.gov/medical-devices/cosmetic-devices/dermal-fillers-approved-center-devices-and-radiological-health|journal=FDA|language=en}}</ref>

=== Medicine ===
* Stabilizer in vaccines.<ref name="Sakaguchi_2000">{{cite journal | vauthors = Sakaguchi M, Inouye S| title = Systemic allergic reactions to gelatin included in vaccines as a stabilizer | journal = Jpn J Infect Dis | volume = 53 | issue = 5 | pages = 189–195| date = 2000 | doi = |pmid = 11135703 }}</ref>
* Originally, gelatin constituted the shells of all drug and vitamin [[Capsule (pharmacy)|capsules]] to make them easier to swallow. Now, a [[vegetarian]]-acceptable alternative to gelatin, [[hypromellose]], is also used, and is less expensive than gelatin to produce.

===Other technical uses===
[[File:Kapsel beredningsform.jpg|thumb|Capsules made of gelatin]]
{{More citations needed section|date=September 2016}}
* Certain professional and theatrical lighting equipment use [[color gel]]s to change the [[Light beam|beam]] color. Historically, these were made with gelatin, hence the term, color gel.
* Some [[animal glue]]s such as hide glue may be unrefined gelatin.<!-- also casein glues -->
* It is used to hold [[silver halide]] crystals in an [[emulsion]] in virtually all [[photographic film]]s and [[photographic paper]]s. Despite significant effort, 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 [[β-carotene]] water-soluble, thus imparting a yellow color to any [[soft drink]]s containing β-carotene.
* [[Ballistic gelatin]] is used to test and measure the performance of [[bullets]] shot from [[firearms]].
* Gelatin is used as a [[binder (material)|binder]] in [[match]] heads<ref>{{cite book|url=https://books.google.com/books?id=r7lTAAAAMAAJ|title=Matchmaking, science, technology, and manufacture|last1=Finch|first1=C. A.|last2=Ramachandran|first2=Srinivasa|date=1983|publisher=Ellis Horwood|isbn=978-0-85312-315-6|page=141|language=en}}</ref> and [[sandpaper]].<ref>{{cite book|url=https://books.google.com/books?id=BOtLMZ8klI8C&pg=PA48|title=Handbook of Adhesion|last=Packham|first=D. E.|year=2006|publisher=John Wiley & Sons|isbn=978-0-470-01421-9|page=48|language=en}}</ref>
* [[Cosmetics]] may contain a non-gelling variant of gelatin under the name hydrolyzed collagen (hydrolysate).
* Gelatin was first used as an external surface [[sizing]] for paper in 1337 and continued as a dominant sizing agent of all European papers through the mid-nineteenth century.<ref>{{cite web|last=Thurn|first=Jim|title=History, Chemistry, and Long Term Effects of Alum-Rosin Size in Paper|url=https://pacer.ischool.utexas.edu/html/2081/1396/j-thurn-03-alum.html|work=ischool.utexas.edu|archive-url=https://web.archive.org/web/20120425053027/https://pacer.ischool.utexas.edu/html/2081/1396/j-thurn-03-alum.html|archive-date=25 April 2012|df=dmy-all}}</ref> In modern times, it is mostly found in watercolor paper, and occasionally in glossy printing papers, artistic papers, and playing cards. It maintains the wrinkles in [[crêpe paper]].
* [[Biotechnology]]: Gelatin is also used in synthesizing [[hydrogel]]s for [[tissue engineering]] applications.<ref>{{Cite journal|last1=Rizwan|first1=Muhammad|last2=Peh|first2=Gary S. L.|last3=Ang|first3=Heng-Pei|last4=Lwin|first4=Nyein Chan|last5=Adnan|first5=Khadijah|last6=Mehta|first6=Jodhbir S.|last7=Tan|first7=Wui Siew|last8=Yim|first8=Evelyn K. F.|date=2017-03-01|title=Sequentially-crosslinked bioactive hydrogels as nano-patterned substrates with customizable stiffness and degradation for corneal tissue engineering applications|url=http://www.sciencedirect.com/science/article/pii/S0142961216307372|journal=Biomaterials|language=en|volume=120|pages=139–54|doi=10.1016/j.biomaterials.2016.12.026|pmid=28061402|issn=0142-9612}}</ref> Gelatin is also used as a saturating agent in [[immunoassay]]s, and as a coat.<ref>{{cite journal |author=Isomura Mitsuo |author2=Ueno Masayoshi |author3=Shimada Kazuya |author4=Ashihara Yoshihiro |title=Magnetic Particles with Gelatin and Immunoassay using the same | website=Europe PMC | url=http://europepmc.org/article/PAT/EP0709680 | date= 8 July 1994|access-date=2021-06-18}}</ref> Gelatin degradation assay allows visualizing and quantifying invasion at the subcellular level instead of analyzing the invasive behavior of whole cells, for the study of cellular protrusions called [[invadopodia]] and [[podosome]]s, which are protrusive structures in cancer cells and play an important role in cell attachment and remodeling of the [[extracellular matrix]] (ECM).<ref>{{cite journal | last=Díaz | first=Begoña | title=Invadopodia Detection and Gelatin Degradation Assay | journal=Bio-Protocol | volume=3 | issue=24 | date=2013-12-20 | issn=2331-8325 | pmid=30443559 | pmc=6233998 | doi=10.21769/bioprotoc.997 | page=}}</ref>

== Gelatin derivatives ==
Gelatin methacryloyl (GelMA) is a chemically modified derivative of gelatin, produced by introducing methacryloyl functional groups onto gelatin's amine and hydroxyl residues. This modification allows GelMA to undergo photocrosslinking in the presence of a photoinitiator, forming stable hydrogels with tunable mechanical properties.<ref>{{Cite journal |last=Zhu |first=Mengxiang |last2=Wang |first2=Yingying |last3=Ferracci |first3=Gaia |last4=Zheng |first4=Jing |last5=Cho |first5=Nam-Joon |last6=Lee |first6=Bae Hoon |date=2019-05-03 |title=Gelatin methacryloyl and its hydrogels with an exceptional degree of controllability and batch-to-batch consistency |url=https://www.nature.com/articles/s41598-019-42186-x |journal=Scientific Reports |language=en |volume=9 |issue=1 |pages=6863 |doi=10.1038/s41598-019-42186-x |issn=2045-2322|hdl=10356/106551 |hdl-access=free }}</ref> Additionally, the introduction of methacrylated groups enhances GelMA's mucoadhesive properties, making it particularly useful for mucosal drug delivery applications.<ref>{{Cite journal |last=Shatabayeva |first=Elvira O. |last2=Kaldybekov |first2=Daulet B. |last3=Ulmanova |first3=Leila |last4=Zhaisanbayeva |first4=Balnur A. |last5=Mun |first5=Ellina A. |last6=Kenessova |first6=Zarina A. |last7=Kudaibergenov |first7=Sarkyt E. |last8=Khutoryanskiy |first8=Vitaliy V. |date=2024-03-11 |title=Enhancing Mucoadhesive Properties of Gelatin through Chemical Modification with Unsaturated Anhydrides |url=https://pubs.acs.org/doi/full/10.1021/acs.biomac.3c01183 |journal=Biomacromolecules |volume=25 |issue=3 |pages=1612–1628 |doi=10.1021/acs.biomac.3c01183 |issn=1525-7797 |pmc=10934270 |pmid=38319691}}</ref> Due to its biocompatibility, biodegradability, and ability to mimic the extracellular matrix, GelMA has gained widespread applications in tissue engineering, drug delivery, and biofabrication. It is particularly useful in 3D bioprinting, wound healing, and the development of organ-on-a-chip models. Its capacity to support cell adhesion, proliferation, and differentiation further makes it an attractive biomaterial for regenerative medicine and biomedical research.<ref>{{Cite journal |last=Yue |first=Kan |last2=Trujillo-de Santiago |first2=Grissel |last3=Alvarez |first3=Mario Moisés |last4=Tamayol |first4=Ali |last5=Annabi |first5=Nasim |last6=Khademhosseini |first6=Ali |date=2015-12-01 |title=Synthesis, properties, and biomedical applications of gelatin methacryloyl (GelMA) hydrogels |url=https://www.sciencedirect.com/science/article/abs/pii/S014296121500719X |journal=Biomaterials |volume=73 |pages=254–271 |doi=10.1016/j.biomaterials.2015.08.045 |issn=0142-9612}}</ref>

==Religious considerations==
The consumption of gelatin from particular animals may be forbidden by religious rules or cultural taboos.

Islamic [[halal]] and Jewish [[kosher]] customs generally require gelatin from sources other than pigs, such as cattle that have been slaughtered according to religious regulations (halal or kosher), or fish (that Jews and Muslims are allowed to consume).<ref name=WHO/>

On the other hand, some [[Islam]]ic jurists have argued that the chemical treatment "purifies" the gelatin enough to always be halal, an argument most common in the field of medicine.<ref name=WHO>{{cite web |url=http://www.immunize.org/concerns/porcine.pdf |title=Form letter EDB.7/3 P6/61/3 |publisher=World Health Organization, Regional Office for the Eastern Mediterranean |date=2001-07-17 |author=Gezairy HA |access-date=2009-05-12 |archive-date=3 March 2016 |archive-url=https://web.archive.org/web/20160303212400/http://www.immunize.org/concerns/porcine.pdf |url-status=dead }}</ref>

It has similarly been argued that gelatin in medicine is permissible in Judaism, as it is not used as food.<ref name="Smith2015">{{Cite journal |last=Smith |first=MJ |date=November 2015 |title=Promoting Vaccine Confidence |journal=Infectious Disease Clinics of North America |type=Review |volume=29 |issue=4 |pages=759–769 |doi=10.1016/j.idc.2015.07.004 |pmid=26337737}}</ref> According to ''The [[Jew]]ish Dietary Laws'', the book of kosher guidelines published by the [[Rabbinical Assembly]], the organization of [[Conservative Judaism|Conservative Jewish]] rabbis, all gelatin is kosher and [[pareve]] because the chemical transformation undergone in the manufacturing process renders it a different physical and chemical substance.<ref>{{cite book |author=Samuel H. Dresner |author2=Seymour Siegel |author3=David M. Pollock |title=The Jewish Dietary Laws |year=1982 |publisher=The Rabbinical Assembly |isbn=978-0-8381-2105-4 |pages=97–98}}</ref>

[[Buddhist]], [[Hindu]], and [[Jainism|Jain]] customs may require gelatin alternatives from sources other than animals, as many Hindus, almost all Jains and some Buddhists are vegetarian.<ref>{{Cite book |last1=Schmidt |first1=Arno |last2=Fieldhouse |first2=Paul |title=The World Religions Cookbook |publisher=Greenwood Publishing Group |year=2007 |page=99 |url=https://books.google.com/books?id=QrHPXSP1z-AC&pg=PA99 |isbn=978-0-313-33504-4|via=Googlebooks}}</ref>

==See also==
*[[Agar]]
*[[Carrageenan]]
*[[Konjac]]
*[[Pectin]]
*[[Gulaman]]

==References==
{{Reflist}}

==External links==
{{Commons category-inline}}
{{Fibrous proteins}}
{{Authority control}}

[[Category:Gelatin| ]]
[[Category:Animal products]]
[[Category:Conservation and restoration materials]]
[[Category:Dietary supplements]]
[[Category:Edible thickening agents]]
[[Category:Excipients]]
[[Category:Gels]]
[[Category:Skin care]]
[[Category:Structural proteins]]
[[Category:Photographic chemicals]]