Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Monosodium glutamate: Difference between pages

{{Short description|Chemical compound, flavor enhancer}}

{{about|the chemical compound|its use in food|Glutamate flavoring}}

{{redirect|MSG|the arena in New York City|Madison Square Garden|other uses|MSG (disambiguation)}}

{{Use dmy dates|date=January 2024}}

| Watchedfields = changed

| Name = Monosodium glutamate

| verifiedrevid = 477163037

| ImageFile = Monosodium glutamate Structural Formula V1.svg

| ImageSize = 200px

| ImageAlt = Chemical composition of monosodium glutamate

| ImageFile1 = Monosodium_glutamate_spacefill.png

| ImageFile2 = Monosodium glutamate crystals.jpg

| ImageSize2 = 200px

| IUPACName = Sodium 2-aminopentanedioate

| OtherNames =

| Section1 = {{Chembox Identifiers

| EC_number = 205-538-1

| PubChem=23672308

| Section2 = {{Chembox Properties

| Formula=C₅H₈NO₄Na

| MolarMass=169.111 g/mol (anhydrous), 187.127 g/mol (monohydrate)

| Appearance=White crystalline powder

| Density=322

| Solubility=740 g/L

}}

| Section3 = {{Chembox Hazards

| NFPA-H = 0

| NFPA-F = 0

| NFPA-R = 0

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| LD50 = 16600&nbsp;mg/kg (oral, rat)<ref>{{cite journal | last=Pinto-Scognamiglio | first=W. | last2=Amorico | first2=L. | last3=Gatti | first3=G. L. | title=[Toxicity and tolerance to monosodium glutamate studied by a conditioned avoidance test] | journal=Il Farmaco; Edizione Pratica | volume=27 | issue=1 | date=1972 | issn=0430-0912 | pmid=5059711 | pages=19–27}}</ref>

| AutoignitionPt =

'''Monosodium glutamate''' ('''MSG'''), also known as '''sodium glutamate''', is a [[sodium]] [[Salt (chemistry)|salt]] of [[glutamic acid]]. MSG is found naturally in some foods including [[tomato]]es and [[cheese]] in this glutamic acid form.<ref name=FDA>{{cite web |title=Questions and Answers on Monosodium glutamate (MSG) |url=https://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm328728.htm |website=www.fda.gov |publisher=U.S. Food and Drug Administration |date=19 November 2012|quote=MSG occurs naturally in many foods, such as tomatoes and cheeses}}</ref><ref name="HealthCanada">{{cite web|title=Monosodium glutamate (MSG) – Questions and Answers|url=https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/monosodium-glutamate-questions-answers.html|website=Government of Canada|access-date=20 May 2018|date=29 January 2008}}</ref><ref name="Agostoni_2000">{{cite journal | vauthors = Agostoni C, Carratù B, Boniglia C, Riva E, Sanzini E | title = Free amino acid content in standard infant formulas: comparison with human milk | journal = Journal of the American College of Nutrition | volume = 19 | issue = 4 | pages = 434–8 | date = August 2000 | pmid = 10963461 | doi = 10.1080/07315724.2000.10718943 | s2cid = 3141583 }}</ref> MSG is used in cooking as a flavor enhancer with a savory taste that intensifies the meaty, savory flavor of food, as naturally occurring glutamate does in foods such as [[stew]]s and meat soups.<ref name="Ikeda">{{cite journal |author=Ikeda K |title=New seasonings |journal=Chem Senses |volume=27 |issue=9 |pages=847–49 |date=November 2002 |pmid= 12438213 |doi=10.1093/chemse/27.9.847|doi-access=free }}</ref><ref name="OMG I love MSG">{{cite news|last1=Hayward|first1=Tim|title=OMG I love MSG|url=http://www.ft.com/cms/s/0/45578b88-ff2d-11e4-84b2-00144feabdc0.html#axzz424XCOJsY|archive-url=https://ghostarchive.org/archive/20221210211223/https://www.ft.com/content/45578b88-ff2d-11e4-84b2-00144feabdc0#axzz424XCOJsY|archive-date=10 December 2022|url-access=subscription|url-status=live|website=[[Financial Times]]|date=22 May 2015|publisher=Nikkei|access-date=5 March 2016}}</ref>

MSG was first prepared in 1908 by Japanese [[biochemist]] [[Kikunae Ikeda]], who tried to isolate and duplicate the savory taste of ''[[kombu]]'', an edible [[seaweed]] used as a [[broth]] (''[[dashi]]'') for [[Japanese cuisine]]. MSG balances, blends, and rounds the perception of other tastes.<ref name="Loliger">{{cite journal |author=Loliger J |title=Function and importance of Glutamate for Savory Foods |journal=[[Journal of Nutrition]] |volume=130 |issue=4s Suppl |pages=915s–20s |date=April 2000 |pmid=10736352|doi=10.1093/jn/130.4.915S |doi-access=free }}</ref><ref name="Yamaguchi91">{{cite journal |author=Yamaguchi S |title=Basic properties of umami and effects on humans |journal=[[Physiology & Behavior]] |volume=49 |issue=5 |pages=833–41 |date=May 1991 |pmid=1679557|doi=10.1016/0031-9384(91)90192-Q|s2cid=20980527 }}</ref> MSG, along with [[disodium ribonucleotides]], is commonly used and found in [[stock cube|stock (bouillon) cubes]], [[soup]]s, [[ramen]], [[gravy]], [[stew]]s, [[condiment]]s, savory [[snack]]s, etc.

The U.S. [[Food and Drug Administration]] has given MSG its [[generally recognized as safe]] (GRAS) designation.<ref name="FDAQnA" /> It is a popular misconception that MSG can cause [[headaches]] and other feelings of discomfort, known as "[[Chinese restaurant syndrome]]". Several [[blinded study|blinded studies]] show no such effects when MSG is combined with food in normal concentrations, and are inconclusive when MSG is added to broth in large concentrations.<ref name="FDAQnA">{{cite web|title=Questions and Answers on Monosodium glutamate (MSG) |url=https://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm328728.htm |publisher=U.S. Food and Drug Administration |date=19 November 2012 |access-date =4 February 2014}}</ref><ref name="Ob2016">{{cite journal|last1=Obayashi|first1=Y|last2=Nagamura|first2=Y|title=Does monosodium glutamate really cause headache?: a systematic review of human studies|journal=[[The Journal of Headache and Pain]]|date=17 May 2016|volume=17|page=54|doi=10.1186/s10194-016-0639-4|pmid=27189588|pmc=4870486|issue=1|doi-access=free}}</ref><ref>{{Cite AV media|url=http://www.businessinsider.com/msg-ingredients-side-effects-2014-6|first=Will|last=Wei|date=16 June 2014|title=The Truth Behind Notorious Flavor Enhancer MSG|work=Business Insider|type=Podcast|access-date=13 November 2017}}</ref> The [[European Union]] classifies it as a [[food additive]] permitted in certain foods and subject to quantitative limits. MSG has the [[HS code]] 29224220 and the [[E number]] E621.<ref name="UKGovEnumbr">{{cite web|url=http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |title=Current EU approved additives and their E Numbers |publisher=Food.gov.uk |date=26 November 2010 |access-date=30 January 2012}}</ref>

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=={{anchor|Usage}}Use==

Pure MSG is reported not to have a highly pleasant taste until it is combined with a savory [[aroma]].<ref name=Rolls09>{{cite journal|author=Rolls, Edmund T. |title=Functional neuroimaging of umami taste: what makes umami pleasant? |journal=The American Journal of Clinical Nutrition|volume=90 |issue=3 |pages=804S–13S|date=September 2009 |pmid=19571217 |doi=10.3945/ajcn.2009.27462R |doi-access=free }}</ref> The basic sensory function of MSG is attributed to its ability to enhance savory taste-active compounds when added in the proper concentration.<ref name="Loliger" /> The optimal concentration varies by food; in [[clear soup]], the "pleasure score" rapidly falls with the addition of more than one gram of MSG per 100{{Nbsp}}mL.<ref name="Umami">{{cite book|title=Umami: a basic taste|veditors=Kawamura Y, Kare MR |publisher=Marcel Dekker Inc.| location=New York, NY|year=1987}}</ref>

The sodium content (in [[mass percent]]) of MSG, 12.28%, is about one-third of that in [[sodium chloride]] (39.34%), due to the greater mass of the glutamate counterion.<ref name="Yamaguchi06">{{cite journal |author =Yamaguchi, Shizuko |author2=Takahashi, Chikahito |title=Interactions of monosodium glutamate and sodium chloride on saltiness and palatability of a clear soup |journal=[[Journal of Food Science]]|volume=49 |issue=1 |pages=82–85|date=January 1984|doi=10.1111/j.1365-2621.1984.tb13675.x }}</ref> Although other salts of glutamate have been used in low-salt soups, they are less palatable than MSG.<ref name="Ball02">{{cite journal |vauthors=Ball P, Woodward D, Beard T, Shoobridge A, Ferrier M |title=Calcium diglutamate improves taste characteristics of lower-salt soup|journal= Eur J Clin Nutr|volume=56 |issue=6 |pages=519–23|date=June 2002 |pmid=12032651|doi=10.1038/sj.ejcn.1601343 |doi-access=free }}</ref> [[Food scientist]] Steve Witherly noted in 2017 that MSG may promote healthy eating by enhancing the flavor of food such as [[kale]] while reducing the use of [[salt]].<ref>{{cite web|url=https://www.businessinsider.com/cooking-with-msg-supersalt-2017-2|title=Everyone should cook with MSG, says food scientist|last=Lubin|first=Gus|website=Business Insider|date=2 February 2017|access-date=27 January 2019}}</ref>

The [[ribonucleotide]] food additives [[disodium inosinate]] (E631) and [[disodium guanylate]] (E627), as well as conventional salt, are usually used with monosodium glutamate-containing ingredients as they seem to have a synergistic effect. "Super salt" is a mixture of 9 parts salt, to one part MSG and 0.1 parts [[disodium ribonucleotides]] (a mixture of [[disodium inosinate]] and [[disodium guanylate]]).<ref>{{Cite web | url=https://www.businessinsider.com/cooking-with-msg-supersalt-2017-2?r=US&IR=T | title=Everyone should cook with MSG, says food scientist| website=[[Business Insider]]}}</ref>

==Safety==

MSG is [[generally recognized as safe]] to eat.<ref name=FDA/><ref>{{cite web|url=https://fivethirtyeight.com/features/how-msg-got-a-bad-rap-flawed-science-and-xenophobia/|title=How MSG Got A Bad Rap: Flawed Science And Xenophobia|first=Anna Maria|last=Barry-Jester|date=8 January 2016}}</ref> A popular belief is that MSG can cause headaches and other feelings of discomfort, but [[Blinded experiment|blinded tests]] have not provided strong evidence of this.<ref name=Ob2016 /> International bodies governing food additives currently consider MSG safe for human consumption as a flavor enhancer.<ref name="Walker00">{{cite journal |vauthors=Walker R, Lupien JR |title=The safety evaluation of monosodium glutamate|journal=Journal of Nutrition|volume=130 |issue=4S Suppl |pages=1049S–52S|date=April 2000 |pmid=10736380 |doi=10.1093/jn/130.4.1049S|doi-access=free}}</ref> Under normal conditions, humans can metabolize relatively large quantities of glutamate, which is naturally produced in the gut in the course of protein hydrolysis. The [[median lethal dose]] (LD₅₀) is between 15 and 18 g/kg body weight in rats and mice, respectively, five times the LD₅₀ of [[salt|table salt]] (3 g/kg in rats). The use of MSG as a food additive and the natural levels of glutamic acid in foods are not of toxic concern in humans.<ref name="Walker00" /> Specifically MSG in the diet does not increase glutamate in the brain or affect brain function.<ref>{{cite journal |last1=Fernstrom |first1=John D. |title=Monosodium Glutamate in the Diet Does Not Raise Brain Glutamate Concentrations or Disrupt Brain Functions |journal=Annals of Nutrition and Metabolism |date=2018 |volume=73 |issue=Suppl. 5 |pages=43–52 |doi=10.1159/000494782|pmid=30508818 |doi-access=free}}</ref>

A 1995 report from the [[Federation of American Societies for Experimental Biology]] (FASEB) for the [[United States Food and Drug Administration]] (FDA) concluded that MSG is safe when "eaten at customary levels" and, although a subgroup of otherwise-healthy individuals develop an MSG symptom complex when exposed to 3 g of MSG in the absence of food, MSG as a cause has not been established because the symptom reports are anecdotal.<ref name="FASEB">{{cite journal|vauthors=Raiten DJ, Talbot JM, Fisher KD |title=Executive Summary from the Report: Analysis of Adverse Reactions to Monosodium Glutamate (MSG) |journal=Journal of Nutrition |volume=125 |issue=6 |pages=2891S–2906S |year=1996 |pmid=7472671 |doi=10.1093/jn/125.11.2891S |s2cid=3945714 }}</ref>

According to the report, no data supports the role of glutamate in [[chronic disease]]. High quality evidence has failed to demonstrate a relationship between the MSG symptom complex and actual MSG consumption. No association has been demonstrated, and the few responses were inconsistent. No symptoms were observed when MSG was used in food.<ref name="freeman" /><ref name="geha">{{cite journal |author=Geha RS |title=Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study |journal=J. Nutr. |volume=130 |issue=4S Suppl |pages=1058S–62S |date=April 2000 |pmid=10736382 |doi=10.1093/jn/130.4.1058S |url=http://jn.nutrition.org/content/130/4/1058.long |name-list-style=vanc |author2=Beiser A |author2-link=Alexa Beiser |author3=Ren C |display-authors=3 |last4=Patterson |first4=R |last5=Greenberger |first5=PA |last6=Grammer |first6=LC |last7=Ditto |first7=AM |last8=Harris |first8=KE |last9=Shaughnessy |first9=MA |url-status=dead |archive-url=https://web.archive.org/web/20120114164740/http://jn.nutrition.org/content/130/4/1058.long |archive-date=14 January 2012 |doi-access=free}}</ref><ref name="Tarasoff">{{cite journal|author1=Tarasoff L. |author2=Kelly M.F. |title=Monosodium L-glutamate: a double-blind study and review |journal=Food Chem. Toxicol. |volume=31 |issue=12 |pages=1019–35 |year=1993 |pmid=8282275 |doi=10.1016/0278-6915(93)90012-N}}</ref><ref>{{cite journal |author=Walker R |title=The significance of excursions above the ADI. Case study: monosodium glutamate |journal=Regul. Toxicol. Pharmacol. |volume=30 |issue=2 Pt 2 |pages=S119–21 |date=October 1999 |pmid=10597625 |doi=10.1006/rtph.1999.1337}}</ref>

Adequately controlling for experimental bias includes a blinded, [[placebo-controlled]] [[experimental design]] and administration by capsule, because of the unique aftertaste of glutamates.<ref name="Tarasoff" /> In a 1993 study, 71 fasting participants were given 5 g of MSG and then a standard breakfast. One reaction (to the placebo, in a self-identified MSG-sensitive individual) occurred.<ref name="freeman" /> A study in 2000 tested the reaction of 130 subjects with a reported sensitivity to MSG. Multiple trials were performed, with subjects exhibiting at least two symptoms continuing. Two people out of the 130 responded to all four challenges. Because of the low prevalence, the researchers concluded that a response to MSG was not reproducible.<ref>{{cite journal|author1=Williams, A. N. |author2=Woessner, K.M. |title=Monosodium glutamate 'allergy': menace or myth? |journal=Clinical & Experimental Allergy |volume=39 |pages=640–46 |year=2009 |doi=10.1111/j.1365-2222.2009.03221.x|pmid=19389112 |issue=5 |s2cid=20044934}}</ref>

Studies exploring MSG's role in [[obesity]] have yielded mixed results.<ref>{{cite journal|pmid=20370941|year=2010|last1=Shi|first1=Z|last2=Luscombe-Marsh|first2=ND|last3=Wittert|first3=GA|last4=Yuan|first4=B|last5=Dai|first5=Y|last6=Pan|first6=X|last7=Taylor|first7=AW|title=Monosodium glutamate is not associated with obesity or a greater prevalence of weight gain over 5 years: Findings from the Jiangsu Nutrition Study of Chinese adults|volume=104|issue=3|pages=457–63|doi=10.1017/S0007114510000760|journal=The British Journal of Nutrition|doi-access=free}}</ref><ref name=twsNovK5>{{cite news |author=Bakalar, Nicholas |title=Nutrition: MSG Use is Linked to Obesity |newspaper=The New York Times |quote=Consumption of monosodium glutamate, or MSG, the widely used food additive, may increase the likelihood of being overweight, a new study says. |date=25 August 2008 |url=https://www.nytimes.com/2008/08/26/health/nutrition/26nutr.html |access-date=10 November 2010}}</ref>

Although several studies have investigated anecdotal links between MSG and [[asthma]], current evidence does not support a causal association.<ref>

{{cite journal |author=Stevenson, D. D. |title=Monosodium glutamate and asthma |journal=J. Nutr. |volume=130 |pages=1067S–73S |year=2000 |pmid=10736384 |issue=4S Suppl |doi=10.1093/jn/130.4.1067S |doi-access=free}}</ref>

[[Food Standards Australia New Zealand]] (FSANZ) MSG technical report concludes, <blockquote>"There is no convincing evidence that MSG is a significant factor in causing systemic reactions resulting in severe illness or mortality. The studies conducted to date on Chinese restaurant syndrome (CRS) have largely failed to demonstrate a causal association with MSG. Symptoms resembling those of CRS may be provoked in a clinical setting in small numbers of individuals by the administration of large doses of MSG without food. However, such effects are neither persistent nor serious and are likely to be attenuated when MSG is consumed with food. In terms of more serious adverse effects such as the triggering of [[bronchospasm]] in asthmatic individuals, the evidence does not indicate that MSG is a significant trigger factor."<ref name=FSANZreport>{{cite book|title=Monosodium Glutamate, A Safety Assessment, Technical Report Series No. 20 |url=http://www.foodstandards.gov.au/publications/Documents/MSG%20Technical%20Report.doc |website=FoodStandards.gov.au |publisher=[[Food Standards Australia New Zealand]], Health Minister Chair, Peter Dutton MP |date=June 2003 |access-date=17 January 2015 |isbn=978-0642345202 |issn=1448-3017}}</ref><ref name=FSANZsearch>{{cite web|title=Monosodium glutamate search |url=http://www.foodstandards.gov.au/Search/pages/results.aspx?k=Monosodium+glutamate|website=FoodStandards.gov.au |publisher=[[Food Standards Australia New Zealand]], Health Minister Chair, Peter Dutton MP |access-date=13 August 2014}}</ref></blockquote>

However, the FSANZ MSG report says that although no data is available on average MSG consumption in Australia and New Zealand, "data from the United Kingdom indicates an average intake of 590mg/day, with extreme users (97.5th percentile consumers) consuming 2,330mg/day" (Rhodes et al. 1991).<ref>{{cite journal | last1 = Rhodes | first1 = Joan | last2 = Titherley | first2 = Alison C. | last3 = Norman | first3 = Julie A. | last4 = Wood | first4 = Roger | last5 = Lord | first5 = David W. | date = 1991 | title = A survey of the monosodium glutamate content of foods and an estimation of the dietary intake of monosodium glutamate | url = https://www.tandfonline.com/doi/abs/10.1080/02652039109374021 | journal = Food Additives & Contaminants | volume = 8 | issue = 5 | pages = 663–672 | doi = 10.1080/02652039109374021 | pmc = | pmid = 1818840 | access-date = 25 May 2023 | name-list-style = vanc }}</ref> In a highly seasoned restaurant meal, intakes as high as 5,000&nbsp;mg or more may be possible (Yang et al. 1997).<ref>{{cite journal | last1 = Yang | first1 = William H. | last2 = Drouin | first2 = Michel A. | last3 = Herbert | first3 = Margaret | last4 = Mao | first4 = Yang | last5 = Karsh | first5 = Jacob | date = 1997 | title = The MSG symptom complex: assessment in a double-blind, placebo-controlled, randomized study | url = https://www.jacionline.org/article/S0091-6749(97)80008-5/pdf | journal = The Journal of Allergy and Clinical Immunology | volume = 99 | issue = 6 Pt 1| pages = 757–762 | doi = 10.1016/s0091-6749(97)80008-5 | pmc = | pmid = 9215242 | access-date = 25 May 2023 | name-list-style = vanc }}</ref> When very large doses of MSG (>5 g MSG in a [[Bolus (medicine)|bolus]] dose) are ingested, plasma glutamate concentration will significantly increase. However, the concentration typically returns to normal within two hours. In general, foods providing metabolizable [[carbohydrate]]s significantly attenuate peak plasma glutamate levels at doses up to 150mg/kg body weight. Two earlier studies{{snd}}the 1987 Joint [[FAO]]/[[WHO]] Expert Committee on Food Additives (JECFA) and the 1995 [[Federation of American Societies for Experimental Biology]] (FASEB){{snd}}concluded, "there may be a small number of unstable asthmatics who respond to doses of 1.5–2.5 g of MSG in the absence of food". The FASEB evaluation concluded, "sufficient evidence exists to indicate some individuals may experience manifestations of CRS when exposed to a ≥3 g bolus dose of MSG in the absence of food".<ref name=FSANZreport />

==Production==

MSG has been produced by three methods: [[hydrolysis]] of vegetable proteins with hydrochloric acid to disrupt [[peptide bond]]s (1909–1962); direct chemical synthesis with [[acrylonitrile]] (1962–1973), and [[bacterial fermentation]] (the current method).<ref name=Sano09/> [[Wheat gluten (food)|Wheat gluten]] was originally used for [[hydrolysis]] because it contains more than 30&nbsp;g of glutamate and glutamine per 100&nbsp;g of protein. As demand for MSG increased, chemical synthesis and fermentation were studied. The [[polyacrylic acid|polyacrylic]] fiber industry began in Japan during the mid-1950s, and [[acrylonitrile]] was adopted as a base material to synthesize MSG.<ref name="Yoshida70">{{cite journal |vauthors=Yoshida T |title=Industrial manufacture of optically active glutamic acid through total synthesis|journal=Chemie Ingenieur Technik|volume=42 |pages=641–44 |year=1970 |doi=10.1002/cite.330420912 |issue=9–10}}</ref>

As of 2016, most MSG worldwide is produced by [[bacterial fermentation]] in a process similar to making vinegar or yogurt. [[Sodium]] is added later, for neutralization. During fermentation, ''[[Corynebacterium]]'' species, cultured with [[ammonia]] and [[carbohydrate]]s from [[sugar beet]]s, [[sugarcane]], [[tapioca]] or [[molasses]], excrete amino acids into a culture broth from which L-glutamate is isolated. Kyowa Hakko Kogyo (currently [[Kyowa Kirin]]) developed industrial fermentation to produce L-glutamate.<ref name="Kinoshita57">{{cite journal |author=Kinoshita, Shukuo |author2=Udaka, Shigezo |author3=Shimamoto, Masakazu |title =Studies on amino acid fermentation. Part I. Production of L-glutamic acid by various microorganisms |journal=J Gen Appl Microbiol |volume=3 |pages=193–205|year=1957 |doi=10.2323/jgam.3.193 |issue=3|url=https://www.jstage.jst.go.jp/article/jgam1955/3/3/3_3_193/_pdf |doi-access=free }}</ref>

The conversion yield and production rate (from sugars to glutamate) continues to improve in the industrial production of MSG, keeping up with demand.<ref name=Sano09 /> The product, after filtration, concentration, acidification, and crystallization, is glutamate, sodium ions, and water.

==Chemical properties==

The compound is usually available as the [[water of hydration|monohydrate]], a white, odorless, crystalline powder. The solid contains separate sodium cations {{chem|Na|+}} and glutamate anions in [[zwitterion]]ic form, ⁻OOC-CH({{chem|N|H|3|+}})-({{chem|C|H|2}})₂-COO⁻.<ref name=struc>{{cite journal | year = 1989 | title = Crystal and Molecular Structures of Monosodium L-Glutamate Monohydrate | journal = Analytical Sciences | volume = 5 | issue = 1| pages = 121–22 | doi = 10.2116/analsci.5.121 | doi-access = free |author=Sano, Chiaki |author2=Nagashima, Nobuya |author3=Kawakita, Tetsuya |author4=Iitaka Yoichi}}</ref> In solution it [[dissociation (chemistry)|dissociates]] into glutamate and sodium ions.

MSG is freely soluble in water, but it is not [[hygroscopic]] and is insoluble in common organic solvents (such as [[Diethyl ether|ether]]).<ref name="Biochemistry">{{cite book|title=Principles of Biochemistry |editor=Win. C.|publisher=Brown Pub Co.| location=Boston, MA|year=1995}}</ref> It is generally stable under food-processing conditions. MSG does not break down during cooking and, like other amino acids, will exhibit a [[Maillard reaction]] (browning) in the presence of sugars at very high temperatures.<ref name=Yamaguchi98/>

==History==

[[Glutamic acid]] was discovered and identified in 1866 by the German chemist [[Karl Heinrich Ritthausen]], who treated wheat [[gluten]] (for which it was named) with [[sulfuric acid]].<ref>{{cite book |author= Plimmer, R.H.A. |editor1=R.H.A. Plimmer |editor2=F.G. Hopkins |title= The Chemical Constitution of the Protein |url= https://books.google.com/books?id=7JM8AAAAIAAJ&pg=PA114 |access-date= 3 June 2012 |edition= 2nd |series= Monographs on biochemistry |volume= Part I. Analysis |orig-date= 1908 |year= 1912 |publisher= Longmans, Green and Co. |location= London|page= 114}}</ref> [[Kikunae Ikeda]] of [[Tokyo Imperial University]] isolated glutamic acid as a taste substance in 1908 from the seaweed ''[[Laminaria japonica]]'' (''[[kombu]]'') by aqueous extraction and crystallization, calling its taste ''[[umami]]'' ("delicious taste").<ref name="Lindemann02">{{cite journal|author=Lindemann, Bernd |author2=Ogiwara Yoko |author3=Ninomiya, Yuzo |title=The discovery of umami|journal=Chem Senses |volume=27 |issue=9 |pages=843–44 |date=November 2002 |pmid=12438211 |doi=10.1093/chemse/27.9.843|doi-access=free }}</ref><ref>{{cite web|url=https://www.theguardian.com/lifeandstyle/2005/jul/10/foodanddrink.features3|title=If MSG is so bad for you, why doesn't everyone in Asia have a headache?|first=Alex|last=Renton|date=10 July 2005|website=The Guardian}}</ref> Ikeda noticed that ''[[dashi]]'', the Japanese broth of ''[[katsuobushi]]'' and ''kombu'', had a unique taste not yet scientifically described (not sweet, salty, sour, or bitter).<ref name="Lindemann02" /> To determine which glutamate could result in the taste of ''umami'', he studied the taste properties of numerous glutamate salts such as calcium, potassium, ammonium, and magnesium glutamate. Of these salts, monosodium glutamate was the most soluble and palatable, as well as the easiest to crystallize.<ref>{{Cite web|title=Kikunae Ikeda|url=https://www.umamiinfo.com/|access-date=8 February 2022|website=Umami Information Center|language=en}}</ref> Ikeda called his product "monosodium glutamate" and submitted a [[patent]] to produce MSG;<ref name="IkedaPatent">Ikeda K (1908). "A production method of seasoning mainly consists of salt of L-glutamic acid". ''Japanese Patent'' 14804.</ref> the Suzuki brothers began commercial production of MSG in 1909 using the term [[Ajinomoto]] ("essence of taste").<ref name="Sano09">{{cite journal |author=Sano, Chiaki|title=History of glutamate production|journal=The American Journal of Clinical Nutrition|volume=90 |issue=3 |pages=728S–32S|date=September 2009 |pmid=19640955 |doi=10.3945/ajcn.2009.27462F |doi-access=free }}</ref><ref name="Yamaguchi98">{{cite journal |author=Yamaguchi, Shizuko |author2=Ninomiya, Kumiko |title=What is umami?|journal=Food Reviews International |volume=14|issue=2 & 3 |pages=123–38 |year=1998 |doi=10.1080/87559129809541155}}</ref><ref name="Kurihara09">{{cite journal |author=Kurihara K|title=Glutamate: from discovery as a food flavor to role as a basic taste (umami)?|journal=[[The American Journal of Clinical Nutrition]]|volume=90 |issue=3 |pages=719S–22S|date=September 2009 |pmid=19640953 |doi=10.3945/ajcn.2009.27462D |doi-access=free }}</ref>

==Society and culture==

===Regulations===

{{see also|Glutamate flavoring#Regulations}}

====United States====

MSG is one of several forms of glutamic acid found in foods, in large part because glutamic acid (an amino acid) is pervasive in nature. Glutamic acid and its salts may be present in a variety of other additives, including [[hydrolyzed vegetable protein]], [[autolyzed yeast]], [[hydrolyzed yeast]], [[yeast extract]], [[soy]] extracts, and protein isolate, which must be specifically labeled. Since 1998, MSG cannot be included in the term "spices and flavorings". However, the term "''natural flavor/s''" is used by the food industry for glutamic acid (chemically similar to MSG, lacking only the sodium [[ion]]). The [[Food and Drug Administration]] (FDA) does not require disclosure of components and amounts of "''natural flavor/s''."<ref name=FDACFR>{{cite web |title=CFR – Code of Federal Regulations Title 21, Vol 6, Part 501, Subpart B – Specific Animal Food Labeling Requirements |url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=501.22 |website=FDA.gov |publisher=U.S. Food and Drug Administration |access-date=13 August 2014}}</ref>

====Australia and New Zealand====

Standard 1.2.4 of the Australia and New Zealand Food Standards Code requires MSG to be labeled in packaged foods. The label must have the food-additive class name (e.g. "flavour enhancer"), followed by the name of the additive ("MSG") or its [[International Numbering System]] (INS) number, 621.<ref name=AUGovLbl4231>{{cite web|url=http://www.foodstandards.gov.au/foodstandards/foodstandardscode/standard124labelling4231.cfm|archive-url=https://web.archive.org/web/20100821130741/http://www.foodstandards.gov.au/foodstandards/foodstandardscode/standard124labelling4231.cfm|archive-date=21 August 2010 |title=Standard 1.2.4 Labelling of Ingredients |work=Food Standards Code |publisher=Food Standards Australia New Zealand |access-date=15 May 2010}}</ref>

====Pakistan====

The [[Punjab Food Authority]] banned Ajinomoto, commonly known as Chinese salt, which contains MSG, from being used in food products in the [[Punjab, Pakistan|Punjab Province]] of Pakistan in January 2018.<ref>{{cite web|title=Punjab Food Authority bans Chinese salt after scientific panel finds it hazardous for health|url=https://www.dawn.com/news/1383111/punjab-food-authority-bans-chinese-salt-after-scientific-panel-finds-it-hazardous-for-health|website=Dawn|access-date=15 January 2018|date=15 January 2018}}</ref>

===Names===

The following are alternative names for MSG:<ref name=RiveniMSG>{{cite web |last1=Singh, K. K. |last2=Desai, Pinakin |title=Glutamate Chemical |url=http://www.triveniinterchem.com/glutamate.html |website=TriveniInterChem.com |publisher=Riveni InterChem of Triveni Chemicals, manufacturer & supplier of industrial chemicals, India |access-date=11 August 2014 |archive-url=https://web.archive.org/web/20170702070829/http://www.triveniinterchem.com/glutamate.html |archive-date=2 July 2017 |url-status=dead }}</ref><ref name=DesmoExportsProductMSG>{{cite web |last1=Desmo Exports Limited, Chemical Manufacturers and Importers of India |title=Monosodium Glutamate (MSG) |url=http://desmoexports.com/products/msg.htm |website=DesmoExports.com |publisher=Desmo Exports |date=2011 |access-date=11 August 2014 |archive-url=https://web.archive.org/web/20160611013903/http://desmoexports.com/products/msg.htm |archive-date=11 June 2016 |url-status=dead }}</ref>

* Chemical names and identifiers

** Monosodium glutamate or sodium glutamate

** Sodium 2-aminopentanedioate

** Glutamic acid, monosodium salt, monohydrate

** L-Glutamic acid, monosodium salt, monohydrate

** L-Monosodium glutamate monohydrate

** Monosodium L-glutamate monohydrate

** MSG monohydrate

** Sodium glutamate monohydrate

** UNII-W81N5U6R6U

** Flavour enhancer E621

* Trade names

** Accent, produced by [[B&G Foods]] Inc., Parsippany, New Jersey, US<ref name=BandGAccent>{{cite web|title=Accent Flavor Enhancer|url=http://www.accentflavor.com/products/accent-flavor-enhancer/|website=AccentFlavor.com|publisher=B&G Foods, Inc.|access-date=11 August 2014|archive-date=17 June 2014|archive-url=https://web.archive.org/web/20140617221214/http://www.accentflavor.com/products/accent-flavor-enhancer/|url-status=dead}}</ref><ref name=BGFoods>{{cite web|title=B&G Foods, Incorporated|url=http://www.grocery.com/bg-foods-incorporated/|website=Grocery.com|access-date=13 August 2014|date=14 July 2011}}</ref>

** Aji-No-Moto, produced by [[Ajinomoto]], 26 countries, head office Japan<ref name=AjiNoMotoMSG>{{cite web|title=Monosodium glutamate(MSG)|url=http://www.ajinomoto.com/features/aji-no-moto/en/truth/ |website=Umami Global Website |publisher=Ajinomoto Co., Inc. |access-date=30 October 2016}}</ref><ref name=AjinomotoCorpGuide>{{cite web|title=To Greet the Next 100 Years (Corporate Guide) |url=http://www.ajinomoto.com/en/aboutus/pdf/ajinomoto_profile.pdf?scid=av_ot_pc_comeheadbp_aboutus_ajinomoto_profile |archive-url=https://web.archive.org/web/20140707041311/http://www.ajinomoto.com/en/aboutus/pdf/ajinomoto_profile.pdf?scid=av_ot_pc_comeheadbp_aboutus_ajinomoto_profile |archive-date=7 July 2014 |publisher=AAjinomoto Co., Inc. |access-date=13 August 2014}}</ref>

** Tasting Powder

** Ve-Tsin by [[Tien Chu Ve-Tsin]]

** Sazón, distributed by [[Goya Foods]], Jersey City, NJ<ref>[http://www.gourmetsleuth.com/ingredients/detail/sazon-seasoning Sazon Seasoning : Substitutes, Ingredients, Equivalents] {{Webarchive|url=https://web.archive.org/web/20150402175148/http://www.gourmetsleuth.com/ingredients/detail/sazon-seasoning |date=2 April 2015 }}. GourmetSleuth. Retrieved on 4 November 2016.</ref>

===Stigma in Western countries===

====Origin====

A controversy surrounding the safety of MSG began on 4 April 1968, when Robert Ho Man Kwok wrote a letter to the ''[[New England Journal of Medicine]]'', coining the term "Chinese restaurant syndrome".<ref name=lem-up>{{cite journal |last1=LeMesurier |first1=Jennifer L. |title=Uptaking Race: Genre, MSG, and Chinese Dinner |journal=Poroi |date=8 February 2017 |volume=12 |issue=2 |pages=1–23 |doi=10.13008/2151-2957.1253|doi-access=free }}</ref><ref name=colgate>{{cite web | author= Blanding, Michael | title=The Strange Case of Dr. Ho Man Kwok |website= Colgate Magazine |date=17 January 2020|url=https://news.colgate.edu/magazine/2019/02/06/the-strange-case-of-dr-ho-man-kwok/ |access-date=6 January 2020}}</ref> In his letter, Kwok suggested several possible causes before he nominated MSG for his symptoms.<ref>{{cite journal |last1=Kwok |first1=Robert Ho Man |title=Chinese-Restaurant Syndrome |journal=New England Journal of Medicine |date=4 April 1968 |volume=278 |issue=14 |page=796 |doi=10.1056/NEJM196804042781419|pmid=25276867 }}</ref><ref name="freeman">{{cite journal| author = Freeman, Matthew | title = Reconsidering the effects of monosodium glutamate: A literature review| journal = Journal of the American Academy of Nurse Practitioners| volume = 18| pages = 482–486| year = 2006| doi = 10.1111/j.1745-7599.2006.00160.x| pmid=16999713| issue = 10| s2cid = 21084909}}</ref> This letter was initially met with insider satirical responses, some using race as prop for humorous effect, within the medical community.<ref name=lem-up/> Some claimed that during the discursive uptake in media, the conversations were recontextualized as legitimate while the supposed race-based motivations of the humor were not parsed.<ref name=lem-up/>

In January 2018, Howard Steel claimed to Jennifer Lemesurier of [[Colgate University]] (who had published an article on the letter) that the letter was actually a prank submission by him under the pseudonym Ho Man Kwok.<ref name=colgate/><ref name="thelongfuse"/> However, there was a Robert Ho Man Kwok who worked at the National Biomedical Research Foundation, both names Steel claimed to have invented.<ref name="thelongfuse"/> Kwok's children, his colleague at the research foundation, and the son of his boss there confirmed that Robert Ho Man Kwok, who had died in 2014, wrote this letter.<ref name="thelongfuse"/> When told this about Kwok's family, Steel's daughter Anna was not very surprised that the story her late father had told so many times over the years was false. He liked to prank people.<ref name="thelongfuse">{{cite news |last1=Sullivan |first1=Lilly |title=668: The Long Fuse |url=https://www.thisamericanlife.org/668/transcript |access-date=7 January 2020 |publisher=This American Life |date=15 February 2019}}</ref>

====Reactions====

Researchers, doctors, and activists have tied the controversy about MSG to [[xenophobia]] and [[racism]] against Chinese culture,<ref>{{cite journal |url=https://jandonline.org/article/S2212-2672(21)00068-X/fulltext#relatedArticles |title=MSG Is A-OK: Exploring the Xenophobic History of and Best Practices for Consuming Monosodium Glutamate |first1=Amanda |last1=Wahlstedt |first2=Elizabeth |last2=Bradley |first3=Juan |last3=Castillo |first4=Kate |last4=Gardner Burt |journal=Journal of the Academy of Nutrition and Dietetics |date=2021 |volume=122 |issue=1 |pages=25–29 |doi=10.1016/j.jand.2021.01.020|pmid=33678597 |s2cid=232143333 }}</ref><ref>{{cite web |last1=Liang |first1=Michelle |title=From MSG to COVID-19: The Politics of America's Fear of Chinese Food |url=https://arts.duke.edu/news/michelle-liang-23-from-msg-to-covid-19-the-politics-of-americas-fear-of-chinese-food/ |website=arts.duke.edu |access-date=9 August 2021 |date=18 May 2020}}</ref><ref>{{cite web |last1=Jiang |first1=Irene |date=15 January 2020| title=McDonald's is testing chicken sandwiches with MSG, and people are freaking out. Here's why they shouldn't care one bit. |url=https://www.businessinsider.com/msg-in-food-dangerous-bad-myth-2020-1 |website=Business Insider}}</ref><ref>{{cite web |last1=Nierenberg |first1=Amelia |title=The Campaign to Redefine 'Chinese Restaurant Syndrome' |url=https://www.nytimes.com/2020/01/16/dining/msg-chinese-restaurant-syndrome-merriam-webster-dictionary.html |website=The New York Times |date=16 January 2020}}</ref><ref>{{cite web |last1=Davis |first1=River |title=The FDA Says It's Safe, So Feel Free to Say 'Yes' to MSG |url=https://www.wsj.com/articles/rescuing-msgs-unsavory-reputation-11556337610 |website=The Wall Street Journal |date=27 April 2019}}</ref> saying that East Asian cuisine is being targeted while the widespread use of MSG in other [[ultra-processed food]]s has not been stigmatized.<ref>{{cite web |title=Why Do People Freak Out About MSG in Chinese Food?|url=https://www.youtube.com/watch?v=Sm8Yx-gWlMs | archive-url=https://ghostarchive.org/varchive/youtube/20211030/Sm8Yx-gWlMs| archive-date=30 October 2021|website=AJ+ (on YouTube) |publisher=[[Al Jazeera Media Network]] |date=14 August 2018 |time=0:00–1:00m and 5:20–8:30m}}{{cbignore}}</ref> These activists have claimed that the perpetuation of the negative image of MSG through the Chinese restaurant syndrome was caused by "xenophobic" or "racist" biases.<ref>{{cite journal |last1=LeMesurier |first1=Jennifer L. |title=Uptaking Race: Genre, MSG, and Chinese Dinner |journal=Poroi |date=8 February 2017 |volume=12 |issue=2 |pages=1–23 |doi=10.13008/2151-2957.1253 | quote=Introduction: 'Chinese Restaurant Syndrome' as Rhetorical [...] Finally, I trace how the journalistic uptakes of this discussion, in only taking up certain medical phrases and terms, reproduce the tacit racism of this boundary policing while avowing the neutrality of medical authority.|doi-access=free }}</ref><ref>{{cite journal |doi=10.52214/curj.v2i1.4115 |year=2017|last1=Germain|first1=Thomas|title=A Racist Little Hat: The MSG Debate and American Culture|journal=Columbia Undergraduate Research Journal|volume=2|doi-access=free}}</ref>

Food historian Ian Mosby wrote that fear of MSG in Chinese food is part of the US's long history of viewing the "exotic" cuisine of Asia as dangerous and dirty.<ref>Anna Barry-Jester, [https://fivethirtyeight.com/features/how-msg-got-a-bad-rap-flawed-science-and-xenophobia/ "How MSG Got A Bad Rap: Flawed Science And Xenophobia,"] FiveThirtyEight, 8 January 2016</ref> In 2016, [[Anthony Bourdain]] stated in [[Parts Unknown (TV series)|''Parts Unknown'']] that "I think MSG is good stuff ... You know what causes Chinese restaurant syndrome? Racism."<ref>{{cite news |last1=Yeung |first1=Jessie |title=MSG in Chinese food isn't unhealthy – you're just racist, activists say |url=https://edition.cnn.com/2020/01/18/asia/chinese-restaurant-syndrome-msg-intl-hnk-scli/index.html |access-date=21 May 2021 |agency=CNN |date=19 January 2020}}</ref>

In 2020, [[Ajinomoto]], the first corporation to mass-produce MSG for consumers and today its leading manufacturer, launched a campaign called "Redefine CRS" to combat what it said was the myth that MSG is harmful to people's health, saying it intended to highlight the xenophobic [[prejudice]] against [[East Asian cuisine]] and the scientific evidence.<ref>{{cite web |last1=Yeung |first1=Jessie |title=MSG in Chinese food isn't unhealthy – you're just racist, activists say |url=https://edition.cnn.com/2020/01/18/asia/chinese-restaurant-syndrome-msg-intl-hnk-scli/index.html |website=CNN |date=19 January 2020}}</ref>

==See also==

{{Columns-list|colwidth=16em|

* [[Acceptable daily intake]]

* [[Adenosine monophosphate]]

* [[Garum]]

* [[Guanosine monophosphate]]

* [[Hydrolyzed vegetable protein]]

* [[Hypoxanthine-guanine phosphoribosyltransferase]]

* [[Inosinic acid]]

* [[Iodized salt]]

* [[Kombu]]

* [[Monopotassium glutamate]]

* [[Murri (condiment)]]

* [[Ribonucleoside]]

* [[Russell Blaylock]]

* [[Table salt]]

* [[Yeast extract]]

}}

==References==

{{Reflist}}

==External links==

{{commons category|Monosodium glutamate}}

{{wiktionary|monosodium glutamate symptom complex|Chinese food syndrome|Chinese restaurant syndrome|CRS}}

* [http://www.eufic.org/en/food-today/article/the-facts-on-monosodium-glutamate The Facts on Monosodium Glutamate (EUFIC)] {{Webarchive|url=https://web.archive.org/web/20170322182410/http://www.eufic.org/en/food-today/article/the-facts-on-monosodium-glutamate |date=22 March 2017 }}

* {{Skeptoid|id=4706|number=706|title=MSG: How a Friendly Flavor Became Your Enemy|date=17 December 2019}}

{{Salt topics}}

{{Sodium compounds}}

{{Consumer Food Safety}}

{{Japanese food and drink}}

{{Anti-Chinese sentiment}}

{{Authority control}}

{{DEFAULTSORT:Monosodium Glutamate}}

[[Category:E-number additives]]

[[Category:Edible salt]]

[[Category:Flavor enhancers]]

[[Category:Food additives]]

[[Category:Glutamates]]

[[Category:Japanese inventions]]

[[Category:Organic sodium salts]]

[[Category:Umami enhancers]]