foods for health, including: the ins and outs of the food sources of pollution, the nature of the classification of harmful substances; in order to prevent pollution and ensure the hygienic quality of food, food production, consumption of the whole process should take appropriate measures.
Sources of pollution and harmful substances in food hygiene food in addition to a handful of food ingredients contain some natural toxins, natural food should be non-toxic harmless. But food cultivation, harvesting, preparation, processing, packaging, storage, transportation, sale until cooked food, range of processes, environmental and human factors, at any time may be harmful biological, chemical substances or other dirt contamination.
Food contaminants according to the human toxic reactions rapid and moderate divided into two major categories of food poisoning pathogens and chronic toxic substances, but they can not be distinct from the chronic toxic substances into the intake and more and focus, can also display acute toxic reactions.
Food poisoning pathogens: food poisoning refers to the normal intake of healthy people but has a number of toxic micro-organisms or toxic substances in contaminated food are not directly borne diseases occur suddenly. Onset of the fierce and concentrated, not timely rescue is likely to cause casualties. To prevent food poisoning is the key tasks of food hygiene. The source of the problem causing the food poisoning can be divided into four categories.
Bacterial food poisoning: Food poisoning caused by bacteria, the most common. Food is toxic to bacterial contamination, the large population, without pasteurization will cause poisoning if swallowed. Common bacteria Salmonella, Proteus, Vibrio parahaemolyticus, pathogenic E. coli, toxigenic Staphylococcus aureus, Clostridium botulinum, Bacillus cereus, Wechsler bacilli. Frequent bacterial food poisoning in summer and autumn, more animal food, plant foods such as leftovers, cool cake, soy, noodles, fermented foods also occur.
Food poisoning mold: mold food poisoning caused by Fusarium wheat flour food poisoning and moldy sugarcane poisoning, the former produce toxins caused by the growth of Fusarium graminearum, the latter by the cane Fu Neurospora crassa, Fusarium moniliforme to produce toxin. In addition, the sweet potato black spot disease can also cause poisoning. Mycotoxins can cause acute poisoning.
Food hygiene food poisoning of chemical substances: food by toxic metals, non-metal and its compounds, pesticides and other toxic chemicals in the process of production, processing, packaging, transportation, pollution, can cause poisoning. The way of pollution, such as non-compliance with the health system, food load had contained toxic chemicals and not cleaned and disinfected container or conveyance, processing using the tools of the chemical instability of the material produced, apparatus, equipment, pipes and containers, In particular, long-term exposure to strong acidic food, a large number of toxic metals dissolve into the food. The more common zinc poisoning, arsenic poisoning, nitrite poisoning. Natural toxins in foods: some animal and vegetable materials contain toxins, such as the puffer fish, toxic shellfish, fresh fish containing histamine, some mushroom, some nucleoli, and cassava contain cyanogenic glycosides, after eating can cause poisoning.
Under normal circumstances, the chronic toxic substances does not cause acute toxic reactions, but the cause of certain diseases or chronic cumulative toxicity. A source of pollution long-term, may also cause serious illness. The epidemiology believe that certain chronic diseases and even cancer with long-term intake of certain toxic substances pollution miscellaneous food. 10 categories of material to produce chronic poisoning.
The source of zoonotic infectious diseases: Some livestock diseases can be transmitted to the human body, known as zoonotic diseases. Such as anthrax, glanders, foot and mouth disease, swine vesicular disease, swine fever, swine erysipelas and swine hemorrhagic septicemia, tuberculosis, brucellosis disease and other infectious diseases, occur in pigs, cattle, sheep, horses, mules, or donkeys who eat by these pathogens contaminated food may cause disease.
Zoonotic parasite pathogens: Some parasitic diseases of livestock, such as cysticercosis (teniasis), trichinosis, pigs, toxoplasmosis, etc., can also be passed to the human body. People to eat foods with these pathogens, may also be sick.
Molds and mycotoxins: dry complete food easy to contamination by mold and mildew, caused by the food change
Quality of food hygiene. Contain highly toxic metabolites of some fungal toxins (called mycotoxins). The epidemiology think flavus and Aspergillus parasiticus produce aflatoxin and liver cancer. Aflatoxin found in peanuts, grains, but when grain water activity of less than 0.83 or moisture content of less than 8% to 12%, no toxins. The ochratoxin Patulin toxicity problems have been cause for concern. Mycotoxins have been varying degrees in more than 200 kinds. Bacteria in general: the contamination of food in addition to pathogens, a large number of non-pathogenic most bacteria. The food by the degree of bacterial contamination in general is an important indicator to evaluate the quality of food hygiene. Natural food materials within the organization is the original and have little or no bacteria. Bacteria in the food mainly from the production, storage, transportation and marketing of all aspects of external contamination, and the breeding and reproduction in food. Unit weight or volume of food contained in the total bacterial number as the total number of bacteria, using a quantitative food plate culture under specified conditions, so that each viable cell to adapt to these conditions must and can only generate a visible colonies, the result is called the total number of colonies of the food, are now commonly used as food hygiene standards. Bacterial contamination is the main reason for food spoilage. An important measure to prevent food spoilage is to reduce opportunities for contact with the bacterial source, control the bacteria on which the breeding conditions, and food to a different degree of sterilization.
Toxic metals: some metal has not yet been proven to have physiological functions in normal circumstances, the body only a very small amount or can only tolerate a very small amount, dose slightly to show the toxic effects of these metals as toxic metals. Toxic metals from the soil, water, air, agricultural chemicals, industrial waste, processing machinery and equipment, pipes, containers, and additives, including mercury, cadmium, lead, arsenic toxicity.
Pesticide contamination: direct contact with a variety of pesticides of agricultural products or through the soil, water, air and transferred to the agricultural products, can cause food contamination. The majority of pesticides on the human body have different degrees of toxicity, all countries in the formulation of regulations, standards, and limit the variety of pesticides, application of the scope of application of the method and allow the residue in the soil. Necessary cleaning and processing of raw materials to food processing to reduce pesticide residues.
Packaging materials pollution: plastics, paints, rubber, metal, ceramics and other materials used by the packaged food, poor quality or improperly used, which contained a variety of chemical additives, monomers of the polymer, the glaze is in the lead salts, coal tar composition of polycyclic aromatic hydrocarbons or metal salts and other toxic substances may be dissolved, thus contaminating food.
Food additives: Most food additives are not natural food ingredients, the misconduct can also be
Food hygiene can cause the performance of various forms of toxicity. Countries have appropriate laws and regulations, quality standards of the provisions of the standards, food additives, limit the use, as well as the additive itself. Pollution in the production process: the food in the production process, because some of the traditional production process requirements, resulting in a number of toxic substances. For example, many food ingredients containing nitrate, nitrite, and Chung amines under a variety of microorganisms can induce the formation of nitrosamine compounds associated with certain types of cancer in the human. Marinated fish, meat, joining forces with nitrate as food hair color, and antibacterial agents to accelerate the synthesis of N-nitrosamines. Another example is the traditional method of burning wood fume barbecue food, also produced with the carcinogenic activity of benzo [a] pyrene and other polycyclic aromatic hydrocarbons. Modern Food Technologists has developed some new techniques to avoid such harmful substances.
Dirt, the vicious impurities: food production, storage and transportation process, due to mismanagement and other reasons, may be mixed with insects, insect limbs, rat hair, rat urine, gravel, dust and other dirt and nails, needle, metal pieces debris, broken glass, wood, paint and other malignant impurities, which seriously affected the food safety and hygiene.