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Safety of dairy products

Safety of dairy products. Dr. A.M. Mortazavian. Introduction. Milk and milk products are indispensable components of the food supply chain Dairy products are consumed by all population groups

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Safety of dairy products

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  1. Safety of dairy products Dr. A.M. Mortazavian

  2. Introduction • Milk and milk products are indispensable components of the food supply chain • Dairy products are consumed by all population groups Possible contamination by either a microbiological, chemical or physical hazard would affect a large population.

  3. Food safety hazards in dairy products

  4. Physical hazards Consist of detectable pieces of non-food material (foreign bodies) such as glass, wood, metal pest, plastic which have found their way into food from: machinery environment packaging personnel

  5. Microbial hazards Microbial hazards pose the greatest immediate food safety threat to the consumer and enter milk via: • Unhealthy animal • People hands • Milking utensils • Water • Production area (GHP) • Ingredients and additives • Packaging and packs

  6. Microbial hazards • Types of microbiological hazards in milk and dairy products:

  7. Bacterial hazards Various bacteria of public health concern found in milk and dairy products include: • M. tuberculosis • Brucellamelitancis • Salmonella spp. • Listeria monocytogenes • Campylobacter jejuni • Yersinia enterocolitica • Pathogenic strains of Escherichia coli • Enterotoxigenic strains of Staphylococcus aureus

  8. Protozoan parasites • Cryptosporidium parvum • Entamoebahistolytica • Giardialamblia • Toxoplasmagondii Viral hazards • Enteroviruses, including polioviruses and Coxsackie virus, Rotaviruses • Foot and mouth disease virus • Hepatitis virus

  9. Antibiotic drugs .

  10. Concerns linked to use of antimicrobials • Potential development of antibiotic-resistant pathogens, which may then complicate human treatment. • sensitive individuals may exhibit allergic reactions to residues of antibiotics and/or their metabolites, as mainly seen with B-lactam antibiotics

  11. Pesticides and insecticides Contamination of feeds arises in the field or store where treatment with pesticides occurs. The common pesticides presented below can enter milk and dairy products.

  12. Consumption of these compounds could lead to cancers such as breast cancer. • OC pesticides are fat soluble, so can be found predominantly in high-fat dairy products such as cream and butter. • Heat treatment of milk and the activity of the starter bacteria in yogurt can decrease its amount. • Most of the developed countries have established maximum residue levels (MRLs) of pesticides in milk and milk products.

  13. Hormone residue Steroid hormones • The amounts of lipophilic hormones (progestrone and estrogen) depend on the fat content of the milk and dairy products. • Food processing does not seem to influence the amount and ratios of the hormones but cheese ripening does. • Probably not only propionic acid bacteria but also other fermenting bacteria or clotting enzymes are responsible for the formation of testosterone during the fermentation process.

  14. Bovine growth hormone (BGH) • BGH increases activity and/or longevity of mammary secretary cells, probably via Insulin-like Growth Factor (IGF)-I produced by the liver and/or the mammary gland. • Raw milk and pasteurized milk could have levels of IGF-I of 5.6 and 8.2 ng mL-1, respectively. • Dairy products that contain hormones (such as IGF-I) could increase breast cancer risk.

  15. Parasiticide drugs Albendazole is a widely used benzimidazoleanthelmentic. Residues of benzimidazole compounds such as • albendazolesulfoxide, • albendazolesulfone and • albendazole 2-amino sulfone can occur in milk and dairy products and it is necessary to observe withdrawal periods for milk after therapy

  16. Dioxine & Polychlorinated biphenyls The known toxic effects of dioxin include Dermal toxicity, Immunotoxicity, Reproductive abnormalities Endocrine disruption Carcinogenicity Dairy products contribute about 1/4 to 1/2 to the dietary intake of total dioxins.

  17. Heavy metals • Elements such as chromium and nickel enter from direct contact with stainless steel dairy equipment. • Heavy metals such as cadmium, lead, mercury, and arsenic are not expected to have any direct contact with milk . • They enter milk through the ingestion of contaminated feed and water by milk-producing animals.

  18. Heavy metals produce toxic effects by replacing essential metal ions existing in the chelates present in body • Even in low-level, exposure to inorganic arsenic is related to increased risk of cancer in lung skin, bladder • Also, developmental arsenic exposure may lead to increases in pancreatic and hematopoietic cancer .

  19. Comparison of heavy metal concentrations in milk samples of different countries

  20. Mycotoxins The most important mycotoxins present in dairy products include:

  21. Aflatoxins are toxic, carcinogenic, and/or teratogenic to humans and animals. • The International Agency for Research on Cancer (1994) classified AFB1 as a class 1 human carcinogen and AFM1 as a class 2B possible human carcinogen • AFM1 is relatively stable in raw and processed milk products and is not destroyed by regular heat treatments including pasteurization. • AFM1 has chronic and acute effects on human health.

  22. Melamine • Transfer of melamine from melamine-containing feed to cow’s milk has been reported. • Furthermore, melamine is a minor metabolite of the pesticide cyromazine and is also used in some fertilizers. • The primary target for the toxic action of melamine is the kidneys and the urinary tract. • Levels of melamine reported in dairy products ranged from 0.09 to 6200 mg/kg

  23. Processed- produced compounds in dairy products • Two important factors (such as proteins, fats, carbohydrates, and vitamins) can generate carcinogenic and mutagenic compounds from dairy ingredients : 1) sever heating 2) exposure to sunlight • Reactions intensified by high temperature : • Pyrolysis and decomposition • fat oxidation • Maillard reactions

  24. Fat auto-oxidation and photo-oxidation in high- fat dairy products Free radicals Polymerized compounds Induction of Cancer

  25. Maillard reaction • The Maillard reaction has considerable consequences on the quality of heated milk and milk products in terms of color, flavor nutritional value probable toxic compounds • Nutritional loss (Lys, Pro, lactose, fat)/Schiff base is digestible but become indigestible after Amadori rearrangement due to crosslinking of lactose with Pro, so tripsin can not affects it. • Millard products are act as chelating agents especially for ‘Fe’. • Some of its products might be toxic and/or mutagenic

  26. Crosslinking in proteins dehydroalanine β- elimination Ser Cys heat + Lys + cys lanthionine lysinoalanine

  27. Cholesterol oxidation products (COPs) • COPs level in milk and dairy products is very small. • Formation of COPs in dairy products can only occur under harsh conditions : application of high heating temperatures for a long period long storage at high temperatures, in the case of foods in the dehydrated state or at low water activities. • COPshave many biological effects such as teratogenic, cytotoxic, mutagenic

  28. Dairy Additives Additives such as flavors, colors, sweeteners, antioxidants, and antimicrobial preservatives could possess toxic side effects when exceeding their respective permitted dose of consumption per day. • Brilliant blue FCF, used as a coloring agent, can induce Cancer Malignant tumors Asthma Hyperactivity

  29. Intestine mucous membrane damage or ulcerous colonitis, produce or promote tumor growth • Carageenan as a thickening agent Long- term administration cause • Flavored dairy products that contain sucrose Increase the risk of colorectal cancer insulin resistance pancreatic cancer

  30. Sweeteners such as saccharin and aspartame have been reported to be carcinogenic agent and induce bladder cancer. • Chemical additives such as sodium carbonate and sodium bicarbonate added to milk as neutralizers to preserve it for longer time and to prevent curdling may cause health hazards to the society

  31. Groups of analytes monitored in milk-PNCRC, 2012

  32. Programs for hazards prevention and control in dairy industry

  33. Foundation of HACCP -Prerequisite Programs

  34. An example of possible hazards, control and orientation of yoghurt production

  35. An example of possible hazards, control and orientation of ice-cream production

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