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Introduction and characterization of hazards in seafood

Department of Fisheries and Aquatic Resources (DFAR) Sri Lanka. National Aquatic Resources Research and Development Agency (NARA) Sri Lanka. United Nations University Fisheries Training Programme (UNU-FTP) Iceland. Icelandic International Development Agency (ICEIDA) Iceland.

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Introduction and characterization of hazards in seafood

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  1. Department of Fisheries and Aquatic Resources (DFAR) Sri Lanka National Aquatic Resources Research and Development Agency (NARA) Sri Lanka United Nations University Fisheries Training Programme (UNU-FTP) Iceland Icelandic International Development Agency (ICEIDA) Iceland Introduction and characterization of hazards in seafood Quality and safety issues in fish handling ----- A course in quality and safety management in fishery harbours in Sri Lanka NARA, DFAR, ICEIDA and UNU-FTP

  2. Contents • Food borne hazards • biological hazards • chemical hazards • physical hazards • Preventive measures

  3. Learning objectives After this lecture participants will be familiar with: • food borne hazards and routes of contamination • how to prevent that fish from being contaminated

  4. Hazards • Biological • pathogenic bacteria • viruses • worms • helminths • protozoa Chemical histamine heavy metals pesticidesantibiotics dyes mycotoxin Physical bolts and nuts metal fragments sand

  5. Bacteria These organisms may cause diseases- mild gastroenteritis to severe and sometimes fatal dysentery, cholera or typhoid Faecal pollution - drinking water and sea water

  6. The size of a bacteria5 cm bacteria = 8,5 km man

  7. Bacteria multiply by binary fissionOne bacterium can multiply to one hundred million in only nine hours Growth of bacteria

  8. Harmful microorganisms They can cause: Illness Food spoilage Spoilage of e.g. wood, iron

  9. Pathogenic bacteria in seafood/aquatic food Aquatic environmentVibrio spp. Clostridium botulinum Type E (non-proteolytic) Aeromonas Plesiomonas General environmentListeria monocytogenes Clostridium botulinum Type A,B (proteolytic) C. perfringens Bacillus cereus Animal-human reservoir Salmonella E. coli (EPEC, ETEC, EHEC) S. typhi Staphylococcus aureus Shigella

  10. Factors affecting bacterial growth(Preventive measures) Cleaning and sanitation Personal hygiene Heat (chilling, super chilling, freezing, canning, pasteurizing) Water activity aw ( drying, salting) pH (e.g. fermentation, organic acids) Preservatives (e.g. benzoic and ascorbic acids) Radiation Other (MAP, VP)

  11. Parasites • Numerous different types of parasites exist worldwide, but only about 100 types are known to infect people through food contamination • parasitic worms • protozoa

  12. Pathogenic parasites transmitted by seafood • raw uncooked fish products • Nematodes (round worms • Anisakis simplex - herring • Angiostrongylus spp. -freshwater prawns, snails, fish • Pseudoterranova dicipiens (cod worm) • Cestodes (tape worms) • Diphyllobothrium latum - fresh water • D. pacificum - seawater • Trematodes or flukes • Paragonimus-snails, crustaceans, fishes (lung flukes) • Clonorchis spp. – fresh water fish (liver flukes) • Opisthorchis spp.- fresh water fish

  13. Prevention and control of trematode • The WHO Technical Report on trematode infections details basic strategies for the control of fish-borne trematode infections • Trematodes are more resistant to heat and salt than nematodes • Control programmes involve • detection and treatment • health education • improved sanitation • legislation of food safety measures • management of human faeces • HACCP

  14. Protozoa • About 40 sp. of parasitic protozoans are known to be infectious to humans • Cryptosporidium parvum • Entamoeba histolytica • Giardia lamblia • Cyclospora sp.

  15. Prevention and control • Good personal hygiene • Proper sanitation of toilets seats • Avoid eating raw fruit and vegetables • Treatment of drinking water • slow sand filtration combined with chemical flocculation

  16. Prevention and control • Good personal hygiene • Proper sanitation of toilets seats • Avoid eating raw fruit and vegetables • Treatment of drinking water • slow sand filtration combined with chemical flocculation

  17. Chemical hazards - examples • food additives • veternary drugs residues • pesticides • natural toxicants • mycotoxins, biotoxins • Histamine • environmental contaminants • mercury, lead, cadmium, arsenic, • dioxins

  18. Chemicals hazards, cont. • agricultural chemicals • e.g. pesticides, fungicides, herbicides, fertilizers, antibiotics and growth hormones • prohibited substances • others • e.g. lubricants, cleaning compounds, sanitizers, paint

  19. Major contaminants/pollutants of concern for harbour managers Suspended solids (clay, airborne particulates from industry and plankton etc.) Biodegradable organics ( proteins, carbohydrates and fats) Pathogens Nutrients (Nitrogen, phosphorus and carbon) Priority pollutants (highly toxic chemicals) Refractory organics (pesticides, phenols, surfactants) Heavy metals Dissolved inorganic chemicals (irritant)

  20. Chemical hazards chlorinated phosphate aldrin/deldrin phos pholidon malathion parathion diazinon fertilizers Pesticides

  21. Metal contamination can be from natural sources or from acute or chronic pollution. mercury in its organic form –methylmercury Inorganic mercury can be methylated by biological (microbiological) processes in aquatic environments more than 95% of the total mercury content in edible fish tissue is in the form of methylmercury Bioaccumulation in the food chain highest concentrations are found in predatory fish High pH, increased hardness and high content of soluable and suspended organic compounds - conditions that often prevail in pond aquaculture - reduce mercury uptake. farmed fish usually harvested young – low level Pollutants

  22. Organic pollutants • use of polluted water supplies – chronic contamination from agricultural or industrial chemicals • chlorinated compounds • DDT-dichlorodipheniltrichloroethane, dieldrin, lindane (insecticides) • polychlorinated biphenyls (PCB) , • dioxin like PCBs,

  23. Controlling chemical hazards • Use approved chemicals • specifications • Maintain chemical inventory • Storage procedure • Conduct audits of: • use of chemicals • employee practices • In house training for all employee • Stay updated on regulations and emerging concerns

  24. Natural marine toxins • Scombrotoxin • Ciguatoxin – ciguatera from marine algae - >400 fish spp. • Shellfish toxins • Amnesic shellfish poisoning (ASP)/domoic acid poisoning • Diarrhetic shellfish poisoning (DSP) • Neurotoxic shellfish poisoning (NSP) • Paralytic shellfish poisoning (PSP) • Other marine toxins • Tetrodotoxin - About 80 species of puffer fish, blowfish or fugu • Gempylotoxin -Gemplids, escolars or pelagic mackerels (escolar; oilfish, castor oil fish or purgative fish; snek) • Tetramine marine algae – filter feeding shellfish

  25. Control of disease caused by biotoxins • cannot be entirely prevented • extremely stable: cooking, smoking, drying, salting, does not destroy them • depuration and ozonationare not effective • major preventive measures is: • inspection, sampling from fishing areas and shellfish beds and analysis for toxins

  26. ScombrotoxinBiogenic amines: Histamine Scombroid fish poisoning - Histamine poisoning most common form of toxicity caused by the ingestion of fish Source: Tuna, mackerel, bonita, mahi mahi (Dolphinfish), Growth T°C >5°C, pH 4.7-8.1, salt <5% Symptoms mild disease: facial flushing, urinary problems gastrointestinal and neurological disorder. Symptoms last only for few hours and recovery is complete

  27. Control of scombroid poisoning • Storage below 5 °C at all times • inform the fishermen and processors of the importance of storage at low temperature • sampling and analysis of potentially hazardous species with respect to histamine level • HACCP • temperature/time factors easily measured and recorded • CCP-chilling shortly after catching and killing • the time to decrease the temperature below 10°C should not exceed 2 h. • Good hygienic practices on-board, at landing and during processing

  28. Physical hazards • glass • utensils, bottles windows, lights • metal • equipment, wire, employees • stones • fields, buildings • wood • fields, pallets, boxes, buildings • plastic • packaging materials, pallets, boxes • bone • fish - improper processing • insulation • building material • personal effects • jewellery • cigarettes • hair • paper flaked paint

  29. Controlling physical hazards • GMP´s • Ingredient specifications • Supplier certification • Use equipment to screen for physical hazards • Employee training

  30. References • Huss, H.H., Ababouch, L. and Gram, L. (2004). Assessment and management of seafood safety and quality. FAO Fisheries technical paper 444. • Training material from UNU-FTP/Icelandic Fisheries Laboratories WHO Technical Report Series, No. 883, 1999. Food safety issues associated with products from aquaculture • International Commission on Microbial Specification for Foods (1996). Microorganisms in Foods. 5. Microbiological specifications of food pathogens. Blackwell Scientific Puplications. • Website: http://www.seafood.ucdavis.edu • Lehane and Olley (2000). Histamine fish poisoning revisited. Int. Journal of Food Microbiol. 58, 1-37

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