Acrylamide is an organic compound with the chemical formula CH 2 =CHC(O)NH 2 . It is a white, odorless solid, soluble in water and a variety of organic solvents. From a chemical perspective, acrylamide is a vinyl-substituted primary amide (CONH 2 ). It is mainly produced in industry as a precursor of polyacrylamide, which has many uses as a water-soluble thickener and flocculant.
When cooking at high temperatures above 120 °C (248 °F), acrylamide can form in charred areas of food, especially starchy foods such as potatoes. Despite the health scare following its discovery in 2002, dietary acrylamide is considered unlikely to cause cancer in humans.
make
Acrylamide can be prepared by enzymatic hydration of acrylonitrile:
- CH 2 =CHCN + H 2 O → CH 2 =CHC(O)NH 2
This reaction is also catalyzed by sulfuric acid as well as various metal salts. Treat acrylonitrile with sulfuric acid to obtain acrylamide sulfate, CH=CHC(O)NH 2 ·H 2 SO 4 . This salt can be converted to acrylamide with a base or to methyl acrylate with methanol.
use
Most acrylamide is used in the manufacture of various polymers, especially polyacrylamide. This water-soluble polymer has extremely low toxicity and is widely used as a thickener and flocculant. These functions are valuable in drinking water purification, corrosion inhibition, mineral extraction and papermaking. Polyacrylamide gels are commonly used for purification and analysis in medicine and biochemistry.
Toxicity and carcinogenicity
Acrylamide can be produced in some cooked foods through a series of steps through the reaction of the amino acid asparagine with glucose. This condensation is one of the Maillard reactions, followed by dehydrogenation to produce N- ( D- glucose-1-yl)-L- asparagine , which on pyrolysis produces some acrylamide.
In 2002, the discovery of acrylamide in some prepared foods raised widespread concern about its possible biological effects. IARC, NTP and EPA have classified it as a possible carcinogen, although epidemiological studies have shown that dietary intake of acrylamide does not significantly increase people's risk of cancer.
Europe
According to the European Food Safety Authority, the main toxicity risks of acrylamide are "neurotoxicity, adverse effects on male reproduction, developmental toxicity and carcinogenicity." However, based on their study, there are no concerns about non-tumor effects. In addition, although the relationship between acrylamide intake and cancer has been confirmed in rats and mice, it is unclear whether acrylamide intake affects the risk of cancer in humans. Existing human epidemiological studies are very limited and do not clear conclusion. Show any relationship between acrylamide and human cancer. Food industry workers exposed to twice the average levels of acrylamide did not show higher rates of cancer.
HEOTAX (heat-generated food poisoning) research in Europe
The Thermally Generated Food Toxicants (HEEATOX) project is a multidisciplinary research project funded by the European Commission and ran from the end of 2003 to the beginning of 2007. Its goal is to "assess the health risks that may be associated with harmful compounds in heat-processed foods and to find cooking/processing methods that minimize the content of these compounds, thereby providing safe, nutritious and high-quality foods. It found that acrylamide poses a threat to humans The evidence for cancer risk has strengthened and exposure to acrylamide poses a higher estimated risk to European consumers than many regulated food carcinogens. HEATOX also seeks to provide advice to consumers on how to reduce their intake of acrylamide, In particular, home-cooked foods contribute much less to overall acrylamide levels than industrially prepared foods, and avoiding overcooking is one of the best ways to reduce exposure at home.
USA
Acrylamide is classified as an extremely hazardous substance in the United States, as defined in Section 302 of the United States Emergency Planning and Community Right-to-Know Act (42 USC 11002), and regulations must be followed when producing, storing, or using large amounts of it.
Acrylamide is considered a potential occupational carcinogen by U.S. government agencies and is classified as a Group 2A carcinogen by the International Agency for Research on Cancer. The Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have set the occupational dermal exposure limit at 0.03 mg/m 3 for an eight-hour work day.
Opinions of health organizations
Baking, grilling or grilling food produces large amounts of acrylamide. The discovery in 2002 sparked international health concern. However, subsequent research found that acrylamide in burnt or cooked food was unlikely to cause cancer in humans; Cancer Research UK classified the idea that burnt food causes cancer as a "myth".
The American Cancer Society says laboratory studies suggest acrylamide is a possible carcinogen, but evidence from epidemiological studies as of 2019 suggests dietary acrylamide is unlikely to increase people's risk of the most common types of cancer.
harm
Acrylamide is also a skin irritant, a possible trigger of skin tumors, and may increase the risk of skin cancer. Symptoms of acrylamide exposure include dermatitis and peripheral neuropathy in the exposed area.
Laboratory studies have found that some phytochemicals have the potential to be developed into drugs to reduce the toxicity of acrylamide.
Mechanism
Acrylamide is metabolized to the genotoxic derivative glycidamide. Acrylamide and glycidamide, on the other hand, can detoxify by binding to glutathione.
presence in food
French fries are cooked over high heat.
Acrylamide is found in food, mainly in starchy foods such as potato chips, French fries and bread heated above 120°C. The production of acrylamide during heating is temperature-related.
Acrylamide has been found in roasted barley tea (called mugicha in Japanese) . The barley is roasted, giving it a dark brown color, before being soaked in hot water. During the roasting process, 200-600 μg/kg of acrylamide is produced in mugicha. This is lower than the levels of >1000 μg/kg found in potato chips and other fried whole potato snack foods cited in the same study, and it is unclear how much is ingested after beverage preparation. The levels in rice crackers and sweet potatoes are lower than those in potatoes. The study found that whole cooked potatoes had significantly lower acrylamide levels than other potatoes, suggesting a link between food preparation methods and acrylamide levels.
The levels of acrylamide appear to increase as food is heated longer. Although researchers are still unsure of the exact mechanism by which acrylamide forms in foods, many believe it is a byproduct of the Maillard reaction. In fried or baked goods, acrylamide may result from the reaction of aspartic acid with reducing sugars or reactive carbonyl compounds at temperatures above 120 °C.
Later studies found acrylamide in black olives, dried plums, dried pears, coffee, and peanuts.
present in cigarettes
Smoking is a major source of acrylamide. One study showed it caused an increase in blood acrylamide levels three times higher than any dietary factor.
Acrylamide Q&A
What is acrylamide?
Acrylamide is a chemical that forms in certain foods during high-temperature cooking processes, such as frying, baking, and roasting. Acrylamide in food is formed from sugars and amino acids that occur naturally in food; it does not come from food packaging or the environment.
Are there risks in eating foods containing acrylamide?
Acrylamide has been linked to cancer in animals in studies involving exposure to high doses. In 2010, the Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives (JECFA) concluded that acrylamide is a human health concern and recommended more long-term research. FDA experts participated in the assessment and provided new research data on the risks of acrylamide.
Is acrylamide a new substance in food? When was acrylamide first detected in food?
Acrylamide may always be present in cooked foods. However, acrylamide was first detected in some foods in April 2002.
How is acrylamide formed in food?
Acrylamide is formed from sugars and amino acids during certain types of high-temperature cooking processes, such as frying, roasting, and roasting.
What cooking methods lead to the formation of acrylamide? In what foods is it found?
Cooking at high temperatures, such as frying, baking, or baking, is most likely to result in the formation of acrylamide. Boiling and steaming do not generally form acrylamide. Acrylamide is mainly found in plant-based foods such as potato products, cereal products or coffee. Acrylamide is not formed, or is formed to a lesser extent, in dairy, meat and fish products. Generally speaking, acrylamide is more likely to accumulate when cooking times are longer or temperatures are higher.
What data does the FDA have on acrylamide levels in U.S. foods?
FDA has published the latest data on acrylamide in food in "Acrylamide Survey Data in Food" on the FDA website. The latest data was added to the website in 2019.
Do the levels of acrylamide in organic foods differ from those in other foods?
Because acrylamide is formed through cooking, acrylamide levels in cooked organic foods should be similar to those in cooked non-organic foods.
What action is the FDA taking on acrylamide in food?
Since acrylamide was discovered in foods in 2002, FDA has initiated multiple acrylamide-specific activities, including toxicology studies, analytical method development, food investigations, exposure assessments, formation and mitigation studies, and guidance for industry. Information about FDA's activities regarding acrylamide in food can be found on the agency's acrylamide page.
Should I stop eating fried, baked or roasted foods?
Won't. The FDA's best recommendations regarding acrylamide and diet are for consumers to follow a healthy eating plan consistent with the Dietary Guidelines for Americans (2015-2020) that emphasizes fruits, vegetables, whole grains, and skim or low-fat milk and dairy products; Include lean meats, poultry, fish, beans, eggs, and nuts; and limit saturated fat, trans fat, cholesterol, salt (sodium), and added sugars.
Is acrylamide found elsewhere?
Acrylamide is produced industrially for use in products such as plastics, grouts, water treatment products and cosmetics. Cigarette smoke also contains acrylamide.
What should I do if I want to reduce the amount of acrylamide in the food I cook or eat?
Food choices and acrylamide exposure
Acrylamide is primarily found in foods made from plants, such as potatoes, cereal products and coffee. Acrylamide is not typically associated with meat, dairy, or seafood products.
Acrylamide is typically found in plant foods cooked at high temperatures (such as frying, roasting, and baking) rather than in raw plant foods or foods that are steamed or boiled.
Some foods that are larger sources of acrylamide in the diet include certain potato products (especially French fries and chips), coffee, and cereals (such as breakfast cereals, cookies, and toast). These foods are part of a regular diet. However, if you want to lower your acrylamide intake, cutting back on these foods is one way to do it, keeping in mind that it's best to limit foods high in saturated fat, trans fat, cholesterol, salt (sodium), and added sugars . The FDA does not recommend reducing your intake of healthy grain products, such as whole grain cereals, because they are a good source of whole grains and fiber.
Food storage and preparation methods
- Deep frying results in the highest levels of acrylamide formation compared to frying, baking, and baking potatoes. Baking potato slices reduces the formation of acrylamide, then roasting the whole potato. Cooking potatoes and microwaving whole potatoes with the skin on to make "microwave baked potatoes" do not produce acrylamide.
- Soaking raw potato slices in water for 15-30 minutes before frying or baking can help reduce the formation of acrylamide during cooking. (Soaked potatoes should be drained and blotted before cooking to prevent splattering or fire.)
- Storing potatoes in the refrigerator can cause acrylamide levels to increase during cooking. Therefore, store potatoes outside the refrigerator, preferably in a cool, cool place such as a closet or pantry to prevent sprouting.
- Generally speaking, more acrylamide will accumulate when cooking times are longer or temperatures are higher. Cooking potato products, such as frozen French fries or potato chips, golden rather than brown can help reduce the formation of acrylamide. Brown areas tend to contain more acrylamide.
- Toasting bread light brown instead of dark brown can reduce acrylamide levels. Very brown areas should be avoided as they contain the most acrylamide.
- Acrylamide forms in the coffee when the beans are roasted, not when the coffee is brewed at home or in a restaurant. So far, scientists have not found a good way to reduce the formation of acrylamide in coffee.
