According to the source, food additives are usually divided into three categories internationally: ① natural extracts; (2) substances made by fermentation, such as citric acid. Some of them are synthesized by chemical methods, but their structures are the same as those of natural compounds; ③ Pure chemical compounds, such as sodium benzoate. At present, natural food additives are few in variety and high in price, so many low-cost synthetic food additives have been developed, which makes the types of food additives expand continuously. For example, more than 25,000 different food additives are used in about 20,000 foods in the United States. The EU uses about 1000 ~ 1500 species; The licensed food additives in China have developed from dozens in 1970s to 15 16 currently licensed by the Ministry of Health (as of July 1997), including 996 kinds of edible spices and10/recommended processing AIDS.
According to the functional classification of food additives, FAO/ WHO Food Additives and Pollutants Regulatory Commission (CcFAC) 1988 classifies additives into 2 1 category (excluding nutritional fortifiers, enzyme preparations, spices, etc. ). 1990, China state bureau of technical supervision approved the classification and code of food additives (GB 12493-90). Food additives are divided into 20 categories according to their main functions, including acidity regulator, antagonist, defoamer, antioxidant, bleaching agent, expanding agent, gum base, colorant, color fixative, emulsifier, enzyme preparation, flavor enhancer and so on. In addition, the Ministry of Health suggested that the processing aid should be transferred from 65438 to 0997. At the same time, the Classification and Code of Food Additives (GB 12493-90) stipulates the hygienic supervision and evaluation of new raw materials or new food resources and varieties, including: ① hygienic investigation; ② Toxicological test; ③ Determination of daily allowable intake; ④ Daily actual intake of food additives; ⑤ Approval procedures for the production and use of new food additives. Hygienic investigation includes: understanding the name, source and production unit of additives; Chemical structure, main components; Manufacturing process; Physical and chemical properties and purity; Diet and consumption; Analytical methods; Food safety, chemical changes and their effects on other nutrients and other related experimental materials; Human body data, etc.
With the birth and development of chemical additives, human health is constantly threatened. The toxicity of food additives to human body can be summarized as carcinogenicity, teratogenicity and mutagenicity. The common feature of these toxicities is that it takes a long time to show up, that is, they are potentially toxic to human body, which is why people are concerned about the safety of food additives. For example, animal experiments show that ethoxyphenylurea can not only cause liver cancer, liver tumor and urinary calculi, but also cause poisoning. In addition, animal experiments show that a large intake of benzoic acid will lead to serious liver and stomach diseases and even death; Large intake of p-hydroxybenzoic acid will affect growth and development; Excessive intake of nitrite can cause cancer.
Sometimes, although the toxicity of food additives is low, unexpected toxic substances may be produced due to anti-nutritional factors and the interaction between food ingredients or different additives. Almost all food additives have certain toxicity, but the degree is different, and some food additives have special toxicity. In addition, food additives have superimposed toxicity, that is, two or more chemicals will produce new toxicity after being combined. The superimposed toxicity of food additives is much greater than expected. The general toxicity and special toxicity of food additives have superimposed toxicity. When they are ingested together or at the same time with other chemicals such as pesticide residues and heavy metals, the chemicals that are not carcinogenic will be transformed into carcinogens. Therefore, in addition to paying attention to the food safety of additives in raw materials, processing, final processing and cooking, it is also necessary to fully investigate and study the diseases and superimposed toxicity of harmful substances produced by food intake to the digestive tract.
Food additives are also the cause of children's excessive behavior. Some people in the United States have studied some children's abnormal behaviors such as excessive behavior, excitability and often accompanied by violence, and believe that this is caused by food additives such as salicylic acid, pigments and spices.
Generally speaking, food additives are safe to use within the permitted scope under the supervision and management of health and safety. However, in recent years, some incidents of illegal abuse of food additives affecting food safety are common and have become an important factor threatening food safety. Such as Sudan red, poisonous tea, poisonous bean sprouts and other events of global concern.
1. Sudan Red
On February 16, 2005, the British Food Standards Agency recalled 359 kinds of food contaminated by the synthetic dye Sudan Red on its website, which attracted worldwide attention. The Beijing Food Safety Office immediately launched an investigation, and the Municipal Administration for Industry and Commerce immediately detected "Sudan Red 1" in two samples of "Meiweiyuan" brand Guilin Chili sauce produced by Heinz Meiweiyuan (Guangzhou) Food Co., Ltd. with the batch number of "July 7, 2003". Since then, the Municipal Food Safety Office has organized the departments of industry and commerce, quality inspection, health, entry-exit inspection and quarantine to randomly check more than 2,590 samples in the whole city, and found that 53 batches of food from 29 production enterprises contained Sudan red, and the seized 16 165438 boxes of food containing Sudan red were destroyed in a centralized and unified way. Although the sample of Sudan red only accounts for 1% ~ 2% of the total spot check, its social impact is very bad. Since March 5th, this chemical dye has been continuously detected in Guangzhou, Yunnan, Shanghai and other places, from Chili sauce, spicy fermented bean curd, cooked food to KFC spicy chicken wings ... Beijing Food Safety Office has removed the shelves in time, and deeply traced its sales channels and raw material sources.
According to CCTV's Weekly Quality Report (65438+February 30, 2006), Xi 'an has Chili noodles of Sudan Red 4. In the investigation, the reporter found that several pepper noodle processing factories dyed peppers with Sudan red, and the corn husks dyed with Sudan red were adulterated. Although these factories are small in scale, the daily processing capacity of each factory is more than one or two thousand kilograms. These Chili noodles containing Sudan red dye are mainly sold to the northwest, as well as Sichuan, Hunan, Shandong, Beijing and other places.
Sudan red is a lipophilic azo compound, which mainly includes four types of Sudan red: I, II, III and IV. It is a synthetic red dye, usually used as an industrial dye, and is widely used to enhance the color of solvents, oils, waxes and gasoline, as well as the color of shoes and floors. China has never approved the use of "Sudan Red" dye in food production, and the frequent "Sudan Red" incidents are all caused by illegal additives added to food by food production enterprises.
Studies have shown that "Sudan Red 1" is carcinogenic, which will lead to carcinogenesis in rats, and it also shows the characteristics of possible carcinogenicity in the study of human hepatocytes. Because this kind of dye, regarded as food pigment, will only affect the health of consumers slowly, but will not cause disease soon, so it is very hidden. Long-term consumption of food containing "Sudan Red" may change the DNA structure of the liver and lead to liver diseases.
Be infected with "poisonous tea"
In June, 2005, Biluochun Tea 1000 kg with excessive heavy metals was found in Suzhou market and Lishui, Zhejiang. Illegal traders buy tea raw materials in Guizhou, and use local tea factory workers and technicians brought by counterfeiters to add lead, chromium and green industrial pigments to imitate Biluochun. These so-called "Biluochun", the processing cost of which is about 500g in 75 yuan, are sent to Suzhou City, Jiangsu Province and Lishui City, Zhejiang Province by post office and sold at a price of about 400 yuan per kilogram. The purpose of processing tea with "lead chrome green" pigment is to increase the green color of tea and make the bright green color of tea look better. However, this kind of industrial pigment has high lead content and chromium content, among which the lead content is 60 times higher than the national standard, and it is a terrible "poisonous tea".
Lead chrome green is an industrial pigment, which is mainly used to produce paints, coatings, plastics and paper. Strong coloring ability and not easy to fade. However, lead, chromium and other heavy metal elements in lead-chromium green are toxic, and if ingested, they will cause harm to the human body, so they cannot be eaten. If you use10g of tea with lead, chromium and green added, you can take150g of lead through the tea. In 2000, the China Dietary Research conducted by the Institute of Nutrition and Food Safety of the China Center for Disease Control and Prevention showed that the lead intake level of each adult male was 82.5 micrograms a day, so the lead intake of 10 gram of tea could only reach 150 micrograms, and we can imagine how serious the consequences were. Drinking this tea for a long time will cause damage to the liver or kidney, or damage to the gastrointestinal tract and hematopoietic organs.
3. Poisonous bean sprouts
In July 2005, inspectors found a large number of drugs and chemicals such as penicillin, oxytetracycline and insurance powder in a bean sprout processing factory in Jianggan District of Hangzhou. Operators said that the key to high yield and good appearance of bean sprouts lies in soaking mung beans, and most drugs should be added in the first process, with the best effect. After adding these powerful drugs, the germination rate of mung beans is high and bean sprouts grow fast. Bean sprouts, which originally took ten and a half months to grow, can be listed in advance in just seven days. During this period, hormones and rootless agents should be sprayed every day to ensure the vigorous growth of bean sprouts. 500 grams of mung beans can release at least 5000 grams of bean sprouts. Even the day before the appearance, operators should put in insurance powder to ensure that bean sprouts do not rot. According to the data provided by Hangzhou Agriculture Bureau, the producers of bean sprouts workshops in Jianggan District are mostly foreigners such as Fujian, scattered in more than 20 production sites in Jianqiao and Pengbu towns. These unlicensed workshops produce about 30 tons of bean sprouts every day, accounting for 70% ~ 80% of the daily consumption of bean sprouts in Hangzhou. The quality supervision department of Hangzhou reported that 2.4% of sulfur dioxide remained in the water sample, which was caused by excessive use of insurance powder. Long-term consumption of food with excessive sulfur dioxide residues will cause damage to the human stomach.
To ensure the food safety of food additives, it is necessary to strengthen the management of food additives, including toxicological evaluation of food additives, formulation of standards for the use of food additives, approval procedures for the production or use of food additives, laws and regulations on food additives, etc. The standards for the production and use of food additives in China are based on the toxicological evaluation of food, the needs, effects and suggestions of various departments in the production and use of food additives, and are approved and promulgated by the Ministry of Health and the National Bureau of Standards. The use standard of food additives is a quantitative index to provide the safe use of food additives, including the variety, use, scope and maximum dosage (or residue) of additives. The WHO /FAO Expert Committee on Food Additives laid down the general principles for the use of food additives in 1957, and formulated a series of strict management measures for the safety of food additives and the protection of consumers' interests.
The United States is the first country to formulate and implement laws and regulations on food additives. 1958 revised the food law of 1938, and managed and reviewed some applied food additives, including chemical properties, metabolic process, toxicity, allergic reaction, triple effect test, etc. From 1972 to 10, about 600 kinds of food additives used before 1958 were reviewed in the United States, which was called generally recognized safety (GRAS).
Our government began to manage food additives in 1950s. Since 1960s, the production management and quality supervision of food additives have been strengthened. In view of the special situation of food additives, China has also formulated a series of laws and regulations. For example, in February of 1986, China's National Bureau of Standards approved the Hygienic Standard for the Use of Food Additives (GB 2760-86) and the Hygienic Management Measures for Food Additives. In June 1986 and June 165438+ 10, the Ministry of Health issued the Hygienic Standard for the Use of Food Nutrition Fortifiers (Trial) and the Hygienic Management Measures for Food Nutrition Fortifiers in June 1997, the Ministry of Health issued the Hygienic Standard for the Use of Food Additives (GB 2760