Polycyclic aromatic hydrocarbon (PAH) are a series of aromatic hydrocarbon compounds and their derivatives. At present, about 200 species have been found, most of which are carcinogenic. Benzo (a) pyrene [Benzo (a) Pyrene, B (a) p] is a major food pollutant in polycyclic aromatic compounds.
(1) Sources of pollution from B (a) p in food
1 Smoked baked food pollution. The smoked tobacco used in the smoked food contains polycyclic aromatic hydrocarbon (including B (a) p). When baked, drip on fire the food Fat coking product thermal polymerization reaction, forming B (a) p, attached to the food surface, this is the main source of B (a) p in baked food. When the food is carbonized, the fat is cracked at high temperature, and the free radicals are produced and combined (thermally polymerized) to produce B (a) p, such as the roasted skin, and B (a) p can be up to the 6 70.
2 ink pollution. The ink contains carbon black, carbon black contains several carcinogenic polycyclic aromatic hydrocarbon. Some food packaging paper ink, carbon black polycyclic aromatic hydrocarbon can contaminate food.
3 Asphalt pollution. Asphalt has two kinds of coal tar pitch and petroleum asphalt. The high boiling point fractions above the anthracene Oil of coal tar contain polycyclic aromatic hydrocarbon, and petroleum bitumen B (a) p. The content is less than the coal tar pitch. Farmers in some parts of China often put grain on the road with coal tar pitch, which makes food polluted.
4) Paraffin Oil pollution. Through the wrapping paper the impure paraffin oil, may cause the food to pollute polycyclic aromatic hydrocarbon. Polycyclic aromatic hydrocarbon in impure paraffin paper can also contaminate milk.
5) Environmental pollution. The food atmosphere, water and soil can contaminate plants if they contain polycyclic aromatic hydrocarbon. Some food crops, vegetables and fruits are more polluted.
(3) Harm to human body
B (a) p is mainly through food or water into the body, in the intestines are absorbed, into the blood quickly distributed throughout the body. The mammary gland and adipose tissue can accumulate B (a) p. Animal experiments found that intake of B (a) p through the placenta can enter the fetal body, causing toxicity and carcinogenic effects. B (a) p is excreted mainly through the liver and biliary tract from feces.
B (a) p in rabbits, guinea pigs, rats, mice, ducks, monkeys and other animals, can cause gastric cancer, and can be caused by the placenta tumor, resulting in fetal death and the immune function of the baby mouse decline. B (a) p is a number of short-term mutagenic experimental positive, but it is an indirect mutagenic, in the Ames test and other bacterial mutations, bacterial DNA repair, sister Chromatid exchange, chromosome aberration, mammalian cell culture and sperm abnormalities in mammals are positive.
B (a) The carcinogenic effect of p on human beings, so far there is no definite conclusion. At present, the epidemiological study focuses on the relationship between polycyclic aromatic hydrocarbon and gastric cancer.
(4) Preventive measures
1) Reduce pollution. Improve the roasting process of food, use pure food paraffin as packaging material, strengthen environmental quality control, reduce the pollution of polycyclic aromatic hydrocarbon to environment and food.
2 Limit the content of B (a) p in food. The hygienic standards in our country are as follows: the content of B (a) p in the Shing (Gb7104) and the content of B (a) P Sake 10 (Gb2716 1988) in edible oil.