Acrylamide#Cooking methods that affect acrylamide production

Acrylamide can be prepared by the hydration of acrylonitrile, which is catalyzed enzymatically:{{cite book |doi=10.1002/14356007.a21_143.pub2 |chapter=Polyacrylamides and Poly(Acrylic Acids) |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2015 |last1=Herth |first1=Gregor |last2=Schornick |first2=Gunnar |last3=l. Buchholz |first3=Fredric |pages=1–16 |isbn=9783527306732 }}

:CH₂=CHCN + H₂O → CH₂=CHC(O)NH₂

This reaction also is catalyzed by sulfuric acid as well as various metal salts. Treatment of acrylonitrile with sulfuric acid gives acrylamide sulfate, {{chem2|CH\dCHC(O)NH2*H2SO4}}. This salt can be converted to acrylamide with a base or to methyl acrylate with methanol.

File:RBC Membrane Proteins SDS-PAGE gel.jpg separated by use of polyacrylamide gels (SDS-PAGE)]]

The majority of acrylamide is used to manufacture various polymers, especially polyacrylamide. This water-soluble polymer, which has very low toxicity, is widely used as thickener and flocculating agent. These functions are valuable in the purification of drinking water, corrosion inhibition, mineral extraction, and paper making. Polyacrylamide gels are routinely used in medicine and biochemistry for purification and assays.

File:N-(D-glucos-1-yl)-L-asparagine.png

Acrylamide can arise in some cooked foods via a series of steps by the reaction of the amino acid asparagine and glucose. This condensation, one of the Maillard reactions, followed by dehydrogenation produces N-(D-glucos-1-yl)-L-asparagine, which upon pyrolysis generates some acrylamide.

The discovery in 2002 that some cooked foods contain acrylamide attracted significant attention to its possible biological effects.{{Ullmann|doi=10.1002/14356007.a01_161.pub2|title=Acrylic Acid and Derivatives|year=2003|last1=Ohara|first1=Takashi|last2=Sato|first2=Takahisa|last3=Shimizu|first3=Noboru|last4=Prescher|first4=Günter|last5=Schwind|first5=Helmut|last6=Weiberg|first6=Otto|last7=Marten|first7=Klaus|last8=Greim|first8=Helmut|isbn=3527306730}} IARC, NTP, and the EPA have classified it as a probable carcinogen, although epidemiological studies (as of 2019) suggest that dietary acrylamide consumption does not significantly increase people's risk of developing cancer.

According to the EFSA, the main toxicity risks of acrylamide are "Neurotoxicity, adverse effects on male reproduction, developmental toxicity and carcinogenicity".{{cite journal |title=Scientific Opinion on acrylamide in food |journal=EFSA Journal |date=June 2015 |volume=13 |issue=6 |doi=10.2903/j.efsa.2015.4104 |doi-access=free }} However, according to their research, there is no concern on non-neoplastic effects. Furthermore, while the relation between consumption of acrylamide and cancer in rats and mice has been shown, it is still unclear whether acrylamide consumption has an effect on the risk of developing cancer in humans, and existing epidemiological studies in humans are very limited and do not show any relation between acrylamide and cancer in humans.{{cite web |title=Acrylamide and Cancer Risk |url=https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/acrylamide-fact-sheet |publisher=National Cancer Institute (U.S. Department of Health and Human Services) |date=December 5, 2017 |access-date=April 23, 2018}} Food industry workers exposed to twice the average level of acrylamide do not exhibit higher cancer rates.

Acrylamide is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.{{Cite journal |title=40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities |url=http://edocket.access.gpo.gov/cfr_2008/julqtr/pdf/40cfr355AppA.pdf |url-status=dead |journal=Edocket.access.gpo.gov |edition=July 1, 2008 |publisher=Government Printing Office |archive-url=https://web.archive.org/web/20120225051612/http://edocket.access.gpo.gov/cfr_2008/julqtr/pdf/40cfr355AppA.pdf |archive-date=February 25, 2012 |access-date=October 29, 2011}}

Acrylamide is considered a potential occupational carcinogen by U.S. government agencies and classified as a Group 2A carcinogen by the IARC.{{Cite journal|url = https://www.cdc.gov/niosh/docs/2011-139/pdfs/2011-139.pdf|title = NIOSH skin notation (SK) profile: acrylamide [CAS No. 79-06-1].|last = Dotson|first = GS|date = April 2011|journal = DHHS (NIOSH) Publication No. 2011-139}} The Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have set dermal occupational exposure limits at 0.03 mg/m³ over an eight-hour workday.{{cite web|author=Centers for Disease Control and Prevention|title=Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs) - Acrylamide|url=https://www.cdc.gov/niosh/idlh/79061.html|year=1994}}

Baking, grilling or broiling food causes significant concentrations of acrylamide. This discovery in 2002 led to international health concerns. Subsequent research has however found that it is not likely that the acrylamides in burnt or well-cooked food cause cancer in humans; Cancer Research UK categorizes the idea that burnt food causes cancer as a "myth".{{cite web |date=15 October 2021 |title=Can eating burnt foods cause cancer? |url=https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/cancer-myths/can-eating-burnt-foods-cause-cancer |url-status=live |archive-url=https://web.archive.org/web/20201108152334/https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/cancer-myths/can-eating-burnt-foods-cause-cancer |archive-date=8 Nov 2020 |publisher=Cancer Research UK}}

The American Cancer Society says that laboratory studies have shown that acrylamide is likely to be a carcinogen, but that {{as of|lc=yes|2019}} evidence from epidemiological studies suggests that dietary acrylamide is unlikely to raise the risk of people developing most common types of cancer.{{cite web |date=11 February 2019 |title=Acrylamide and Cancer Risk |url=https://www.cancer.org/cancer/risk-prevention/chemicals/acrylamide.html |publisher=American Cancer Society}}

Radiolabeled acrylamide is also a skin irritant and may be a tumor initiator in the skin, potentially increasing risk for skin cancer. Symptoms of acrylamide exposure include dermatitis in the exposed area, and peripheral neuropathy.

Laboratory research has found that some phytochemicals may have the potential to be developed into drugs which could alleviate the toxicity of acrylamide.{{cite journal |vauthors=Adewale OO, Brimson JM, Odunola OA, Gbadegesin MA, Owumi SE, Isidoro C, Tencomnao T |title=The Potential for Plant Derivatives against Acrylamide Neurotoxicity |journal=Phytother Res |volume= 29|issue= 7|pages= 978–85|year=2015 |pmid=25886076 |doi=10.1002/ptr.5353 |s2cid=5465814 |type=Review}}

file:Glycidamide.svg is the dangerous metabolite produced from acrylamide, which in turn is produced by heating certain proteins.]]

Acrylamide is metabolized to the genotoxic derivative glycidamide. On the other hand, acrylamide and glycidamide can be detoxified via conjugation with glutathione.{{cite journal |doi=10.2903/j.efsa.2015.4104|title=Scientific Opinion on acrylamide in food|journal=EFSA Journal|year=2015|volume=13|issue=6|doi-access=free}}{{cite journal |doi=10.1021/jf030204+|year=2003|volume=51|issue=16|last1=Friedman|first1=Mendel|title=Chemistry, Biochemistry, and Safety of Acrylamide. A Review|journal=Journal of Agricultural and Food Chemistry|pages=4504–4526|pmid=14705871}}

File:Too hot fried french fries IMG 0660.JPG

Acrylamide was discovered in foods, mainly in starchy foods, such as potato chips (UK: potato crisps), French fries (UK: chips), and bread that had been heated higher than {{convert|120|C|F}}. Production of acrylamide in the heating process was shown to be temperature-dependent. It was not found in food that had been boiled,{{cite web|website =Food Standards Agency|title = Acrylamide: your questions answered|date = 3 July 2009 |url=http://www.food.gov.uk/safereating/chemsafe/acrylamide_branch/acrylamide_study_faq/ |url-status=dead |archive-url=https://web.archive.org/web/20120212183149/http://www.food.gov.uk/safereating/chemsafe/acrylamide_branch/acrylamide_study_faq/ |archive-date=2012-02-12 }} or in foods that were not heated.{{cite journal |last1=Tareke |first1=Eden |last2=Rydberg |first2=Per |last3=Karlsson |first3=Patrik |last4=Eriksson |first4=Sune |last5=Törnqvist |first5=Margareta |title=Analysis of Acrylamide, a Carcinogen Formed in Heated Foodstuffs |journal=Journal of Agricultural and Food Chemistry |date=August 2002 |volume=50 |issue=17 |pages=4998–5006 |doi=10.1021/jf020302f |pmid=12166997 }}

Acrylamide has been found in roasted barley tea, called mugicha in Japanese. The barley is roasted so it is dark brown prior to being steeped in hot water. The roasting process produced 200–600 micrograms/kg of acrylamide in mugicha.{{cite journal |last1=Ono |first1=H. |last2=Chuda |first2=Y. |last3=Ohnishi-Kameyama |first3=M. |last4=Yada |first4=H. |last5=Ishizaka |first5=M. |last6=Kobayashi |first6=H. |last7=Yoshida |first7=M. |title=Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods |journal=Food Additives and Contaminants |date=March 2003 |volume=20 |issue=3 |pages=215–220 |doi=10.1080/0265203021000060887 |pmid=12623644 |s2cid=9380981 }} This is less than the >1000 micrograms/kg found in potato crisps and other fried whole potato snack foods cited in the same study and it is unclear how much of this enters the drink to be ingested. Rice cracker and sweet potato levels were lower than in potatoes. Potatoes cooked whole were found to have significantly lower acrylamide levels than the others, suggesting a link between food preparation method and acrylamide levels.

Acrylamide levels appear to rise as food is heated for longer periods of time. Although researchers are still unsure of the precise mechanisms by which acrylamide forms in foods,{{Cite journal | doi=10.1111/j.1365-2621.2003.tb09641.x|title = A Novel Technique for Limitation of Acrylamide Formation in Fried and Baked Corn Chips and in French Fries| journal=Journal of Food Science| volume=68| issue=4| pages=1287–1290|year = 2003|last1 = Jung|first1 = MY| last2=Choi| first2=DS| last3=Ju| first3=JW}} many believe it is a byproduct of the Maillard reaction. In fried or baked goods, acrylamide may be produced by the reaction between asparagine and reducing sugars (fructose, glucose, etc.) or reactive carbonyls at temperatures above {{convert|120|°C|°F|abbr=on}}.{{cite journal|author1=Mottram D.S. |author2=Wedzicha B.L. |author3=Dodson A.T. |title = Acrylamide is formed in the Maillard reaction|journal = Nature|volume = 419|issue = 6906|pages = 448–449|year = 2002|doi = 10.1038/419448a| pmid = 12368844|s2cid=4360610 }}{{cite web|work =Chemistry World|title= Acrylamide cancer link confirmed|url = http://www.rsc.org/chemistryworld/News/2007/December/05120703.asp|last = Van Noorden|first = Richard|date = 5 December 2007}}

Later studies have found acrylamide in black olives,[http://www.foodqualitynews.com/Food-Alerts/Acrylamide-detected-in-prune-juice-and-olives "Acrylamide detected in prune juice and olives"] Food Safety & Quality Control Newsletter 26 March 2004, William Reed Business Media SAS, citing [https://www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/Acrylamide/default.htm "Survey Data on Acrylamide in Food: Total Diet Study Results"] {{webarchive|url=https://web.archive.org/web/20090605153328/https://www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/Acrylamide/default.htm |date=2009-06-05 }} United States Food and Drug Administration February 2004; later updated in June 2005, July 2006, and October 2006 dried plums,{{cite web | url=http://www.ethlife.ethz.ch/archive_articles/070920-acrylamid/index_EN.html | title=Acrylamide in dried Fruits | work=ETH Life | publisher=Swiss Federal Institute of Technology Zurich| date=September 20, 2007 | access-date=2017-05-29| author=Cosby, Renata}}{{cite journal|last1=De Paola|first1=Eleonora L|first2=Giuseppe |last2=Montevecchi |first3=Francesca |last3=Masino |first4=Davide |last4=Garbini |first5=Martino |last5=Barbanera |first6=Andrea |last6=Antonelli |date=February 2017|title=Determination of acrylamide in dried fruits and edible seeds using QuEChERS extraction and LC separation with MS detection|journal=Food Chemistry|volume=217|pages=191–195|pmid=27664625|doi=10.1016/j.foodchem.2016.08.101|hdl=11380/1132604 |hdl-access=free }} dried pears, coffee,{{cite journal |last1=Mucci |first1=Lorelei A. |last2=Sandin |first2=Sven |last3=Bälter |first3=Katarina |last4=Adami |first4=Hans-Olov |last5=Magnusson |first5=Cecilia |last6=Weiderpass |first6=Elisabete |title=Acrylamide Intake and Breast Cancer Risk in Swedish Women |journal=JAMA |date=16 March 2005 |volume=293 |issue=11 |pages=1322–1327 |doi=10.1001/jama.293.11.1326 |pmid=15769965 |s2cid=46166341 }}[http://jifsan.umd.edu/docs/acry2004/acry_2004_dinovihoward.pdf Top Eight Foods by Acrylamide Per Portion] {{Webarchive|url=https://web.archive.org/web/20160302203549/http://jifsan.umd.edu/docs/acry2004/acry_2004_dinovihoward.pdf |date=2016-03-02 }}. p. 17. jifsan.umd.edu (2004). Retrieved on 2012-06-11. and peanuts.

The US FDA has analyzed a variety of U.S. food products for levels of acrylamide since 2002.{{cite web |title=Survey Data on Acrylamide in Food |url=https://www.fda.gov/food/chemical-contaminants-food/survey-data-acrylamide-food |archive-url=https://web.archive.org/web/20210619102534/https://www.fda.gov/food/chemical-contaminants-food/survey-data-acrylamide-food |url-status=dead |archive-date=June 19, 2021 |website=FDA |date=20 February 2020 }}

Cigarette smoking is a major acrylamide source.{{cite web|website = ATSDR |url = https://www.atsdr.cdc.gov/phs/phs.asp?id=1113&tid=236 |title = Public Health Statement for Acrylamide |date = December 2012|publisher = CDC}}{{cite journal |last1=Vesper |first1=H. W. |last2=Bernert |first2=J. T. |last3=Ospina |first3=M. |last4=Meyers |first4=T. |last5=Ingham |first5=L. |last6=Smith |first6=A. |last7=Myers |first7=G. L. |title=Assessment of the Relation between Biomarkers for Smoking and Biomarkers for Acrylamide Exposure in Humans |journal=Cancer Epidemiology, Biomarkers & Prevention |date=1 November 2007 |volume=16 |issue=11 |pages=2471–2478 |doi=10.1158/1055-9965.EPI-06-1058 |pmid=18006939 |doi-access=free}} It has been shown in one study to cause an increase in blood acrylamide levels three-fold greater than any dietary factor.{{cite journal |last1=Thonning Olesen |first1=Pelle |last2=Olsen |first2=Anja |last3=Frandsen |first3=Henrik |last4=Frederiksen |first4=Kirsten |last5=Overvad |first5=Kim |last6=Tjønneland |first6=Anne |title=Acrylamide exposure and incidence of breast cancer among postmenopausal women in the Danish Diet, Cancer and Health Study |journal=International Journal of Cancer |date=8 January 2008 |volume=122 |issue=9 |pages=2094–2100 |doi=10.1002/ijc.23359 |pmid=18183576 |s2cid=22388855 |doi-access=free }}

• Acrydite: research on this compound casts light on acrylamide
• Acrolein
• Alkyl nitrites
• Deep-frying
• Deep fryer
• Vacuum fryer
• Substance of very high concern
• Heterocyclic amines
• Polycyclic aromatic hydrocarbons

{{Reflist}}

• {{Cite journal |last1=Lineback |first1=David R. |last2=Coughlin |first2=James R. |last3=Stadler |first3=Richard H. |date=2012-04-10 |title=Acrylamide in Foods: A Review of the Science and Future Considerations |url=https://www.annualreviews.org/doi/10.1146/annurev-food-022811-101114 |journal=Annual Review of Food Science and Technology |language=en |volume=3 |issue=1 |pages=15–35 |doi=10.1146/annurev-food-022811-101114 |pmid=22136129 |issn=1941-1413|url-access=subscription }}

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