According to media reports, Subway, a global fast food chain, has attracted much attention because of its use of azoformamide as a food additive in the production of bread. It is also reported that bread contains rubber sole ingredients, which has caused concern among consumers. After all, bread is a popular food.
      In response to this incident, Subway China said that its bread suppliers were Asian and local suppliers completely different from those in North America, and all suppliers in Greater China had confirmed that they had not used this chemical ingredient. Whether Chinese consumers can be sure that they are "lucky" to not eat azoformamide.
      In recent years, various baked foods have become an indispensable part of people's daily diet. The protein in flour is mainly composed of glutenin and glutenin. The former is spherical, with good flow and extensibility, but lacks elasticity, while the latter is fibrous and elastic; In order to make the two proteins reach a more appropriate ratio and cross-linking, oxidants need to be added to adjust. In the past decades, potassium bromate has been used in the global food baking industry as a cheap and effective oxidant. The dissolution rate of potassium bromate is slow. With the increase of the acidity of dough fermentation and baking temperature, it is conducive to the production of elastic bread.
      In the 1980s, researchers found that potassium bromate had carcinogenic effect on animals under experimental conditions. In the world, many countries began to ban the use of potassium bromate as an additive in flour products. In 2005, the Ministry of Health of China announced that the use of potassium bromate in flour products was prohibited from July 1, 2005. At the same time, azoformamide began to be widely used in the baking process of flour products instead of potassium bromate because of its safety, effectiveness and low cost.
Azo formamide has dual functions of whitening and oxidation. When it is added to flour to process into dough, it can quickly release reactive oxygen species. At this time, the sulfhydryl group of amino acids in flour protein is oxidized into disulfide bonds, making the protein chains connect with each other to form a three-dimensional network structure, improving the elasticity, toughness and uniformity of the dough, so as to improve the structure and physical properties of flour products, The produced food has large volume and soft taste.
      According to the toxicological research results of azoformamide, its acute toxicity belongs to micro toxicity, and the half lethal dose of azoformamide taken orally by mice is more than 10 g/kg; And relevant medical research believes that it has no mutagenic effect. As a flour additive, azoformamide is allowed to be used in many countries, and has passed the approval certification of WHO and FDA; Standard for Use of Food Additives (GB 2760-2011), as a flour treatment agent, the maximum use amount of azoformamide in wheat flour is 0.045g/kg. It can be concluded that not eating the bread produced and sold by Subway in North America does not guarantee that Chinese consumers will not consume the flour treatment agent azoformamide.
      At present, medical research has not found that the intake of azoformamide, a flour additive that meets the health standards, will lead to poisoning or adverse reactions. Chinese researchers have confirmed that the decomposition products of azoformamide under certain conditions are related to furacilin metabolites, About 0.1% of the flour products containing azoformamide will be converted into furacilin metabolites under the condition of high-temperature thermal hydrolysis. Furacillin is a kind of broad-spectrum antibacterial drug containing nitro group, which has the advantages of strong bactericidal ability, broad antibacterial spectrum, low price and resistance. But research shows that, Furacillin has the tendency of carcinogenesis, teratogenicity and mutagenicity at a certain dose. The European Union banned the use of Furacillin as a veterinary drug in 1995; Australia and the United States also introduced relevant laws in 2001 and 2002, Furacillin is used as a prohibited drug for breeding. Although the study found that the conversion rate of furacilin metabolites of azoformamide contained in flour products was very low, at present, EU countries do not allow the use of azoformamide as a flour improver.