Acrylamide forms in burnt areas of food, particularly starchy foods like potatoes, when cooked with high heat, above 120°C (248°F).[7] Despite health scares following this discovery in 2002, and its classification as a probable carcinogen, there is ongoing debate[citation needed] as to whether acrylamide consumed through diet is likely to cause cancer in humans; Cancer Research UK categorized the idea that eating burnt food causes cancer as a myth.[8][9]
Production
Acrylamide can be prepared by the hydration of acrylonitrile, which is catalyzed enzymatically:[6]
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, CH=CHC(O)NH2·H2SO4. This salt can be converted to acrylamide with a base or to methyl acrylate with methanol.
Uses
Proteins of the erythrocyte 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.[6]
Toxicity and carcinogenicity
N-(D-glucos-1-yl)-L-asparagine, precursor to acrylamide in cooked food[10]
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.
According to the European Food Safety Authority (EFSA), the main toxicity risks of acrylamide are "Neurotoxicity, adverse effects on male reproduction, developmental toxicity and carcinogenicity".[9][12] 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.[9][13] Food industry workers exposed to twice the average level of acrylamide do not exhibit higher cancer rates.[9]
Following the Safe Drinking Water and Toxic Enforcement Act, products in the state of California containing acrylamide had been placed with a warning label explaining that the product contained the chemical and that it was known to cause cancer, birth defects, and reproductive harm.[16] However, starting in 2019, the California Chamber of Commerce challenged the warning label believing it violated first amendment rights.[17] In June of 2025, a Federal District Court In California ruled that the warning label was unconstitutional.[16]
Opinions of health organizations
Baking, grilling or broiling food causes significant concentrations of acrylamide. This discovery in 2002 led to international health concerns. However, subsequent research has 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".[9]
Laboratory research has found that some phytochemicals may have the potential to be developed into drugs which could alleviate the toxicity of acrylamide.[18]
Mechanism of action
Glycidamide 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.[19][20]
Occurrence in food
French fries are cooked to a high temperature.
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 120°C (248°F). Production of acrylamide in the heating process was shown to be temperature-dependent. It was not found in food that had been boiled,[21] or in foods that were not heated.[22]
Acrylamide has been found in roasted barley tea (Japanese: mugicha). 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 roasted barley tea.[23] 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.[23]
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,[24] 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 120°C (248°F).[25][26]
Cigarette smoking is a major acrylamide source.[33][34] It has been shown in one study to cause an increase in blood acrylamide levels three-fold greater than any dietary factor.[35]
See also
Acrydite: research on this compound casts light on acrylamide
↑Tareke, Eden; Rydberg, Per; Karlsson, Patrik; Eriksson, Sune; Törnqvist, Margareta (August 2002). "Analysis of Acrylamide, a Carcinogen Formed in Heated Foodstuffs". Journal of Agricultural and Food Chemistry. 50 (17): 4998–5006. Bibcode:2002JAFC...50.4998T. doi:10.1021/jf020302f. PMID12166997.
12Ono, H.; Chuda, Y.; Ohnishi-Kameyama, M.; Yada, H.; Ishizaka, M.; Kobayashi, H.; Yoshida, M. (March 2003). "Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods". Food Additives and Contaminants. 20 (3): 215–220. doi:10.1080/0265203021000060887. PMID12623644. S2CID9380981.
↑Jung, MY; Choi, DS; Ju, JW (2003). "A Novel Technique for Limitation of Acrylamide Formation in Fried and Baked Corn Chips and in French Fries". Journal of Food Science. 68 (4): 1287–1290. doi:10.1111/j.1365-2621.2003.tb09641.x.
↑Mottram D.S.; Wedzicha B.L.; Dodson A.T. (2002). "Acrylamide is formed in the Maillard reaction". Nature. 419 (6906): 448–449. doi:10.1038/419448a. PMID12368844. S2CID4360610.
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