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FoodhygieneSeafoodHy giene

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Information about FoodhygieneSeafoodHy giene
Education

Published on January 7, 2008

Author: Florence

Source: authorstream.com

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FOOD SAFETY HAZARDS IN AQUACULTURE SEAFOOD HYGIENE Lecture by Géza Szita :  FOOD SAFETY HAZARDS IN AQUACULTURE SEAFOOD HYGIENE Lecture by Géza Szita Chemical compsition of the water:  Chemical compsition of the water Salt concentration of the sea water: 0.35 %:  Salt concentration of the sea water: 0.35 % Chloride (Cl): 55.04 wt% Sodium (Na): 30.61 wt% Sulphate (SO4): 7.68 wt% Magnesium (Mg): 3.69 wt% Calcium (Ca): 1.16 wt.% Potassium (K): 1.10 wt.%:  Chloride (Cl): 55.04 wt% Sodium (Na): 30.61 wt% Sulphate (SO4): 7.68 wt% Magnesium (Mg): 3.69 wt% Calcium (Ca): 1.16 wt.% Potassium (K): 1.10 wt.% Freshwater:  Freshwater Total water 'hardness' (including both Ca2+ and Mg2+ ions):  Total water 'hardness' (including both Ca2+ and Mg2+ ions) Permanent hardness is hardness (mineral content) that cannot be removed by boiling. CaSO4, CaCl2 MgSO4, MgCl2 :  Permanent hardness is hardness (mineral content) that cannot be removed by boiling. CaSO4, CaCl2 MgSO4, MgCl2 Temporary hardness is hardness that can be removed by boiling Ca+HCO3- ▬ CaCO3 + H2O + CO2:  Temporary hardness is hardness that can be removed by boiling Ca+HCO3- ▬ CaCO3 + H2O + CO2 Toxic materials in the water Ammonia NH3 Hydroxil-amine OH- NH2 Nitrite NO2 Nitrate NO3 Hidrogene-sulphide H2S Sulfite ions SO3:  Toxic materials in the water Ammonia NH3 Hydroxil-amine OH- NH2 Nitrite NO2 Nitrate NO3 Hidrogene-sulphide H2S Sulfite ions SO3 1. TERMS, PRODUCTION ~ Seafood: alI fish and shellfish (crustaceans, molluscs) finfish: salt- and fresh-water wild fishery I aquaculture > 300 species shellfish molluscs (salt-water): mussels, snails, clams, oysters, abalone scallops, cuttlefish crustaceans (salt/fresh-water): shrimp or prawns, crayfish,lobsters, crabs etc. :  1. TERMS, PRODUCTION ~ Seafood: alI fish and shellfish (crustaceans, molluscs) finfish: salt- and fresh-water wild fishery I aquaculture > 300 species shellfish molluscs (salt-water): mussels, snails, clams, oysters, abalone scallops, cuttlefish crustaceans (salt/fresh-water): shrimp or prawns, crayfish,lobsters, crabs etc. Molluscs include chitons, clams, mussels, snails, nudibranchs (sea-slugs), tusk shells, octopus and squid. :  Molluscs include chitons, clams, mussels, snails, nudibranchs (sea-slugs), tusk shells, octopus and squid. Characteristics of molluscs Unsegmented soft body Most have internal or external shell Have a mantle (fold in the body wall that lines the shell) Muscular foot and/or tentacles Mollusks:  Mollusks The mollusks or molluscs are the large and diverse phylum Mollusca, which includes a variety of familiar creatures well-known for their decorative shells or as seafood. These range from tiny snails and clams to the octopus and squid (which are considered the most intelligent invertebrates). The giant squid is the largest invertebrate, and, except for their larvae and some recently captured juveniles, has never been observed alive, although the Colossal Squid is likely to be even larger.Mollusks are triploblastic protostomes. The principal body cavity is a blood-filled hemocoel, with an actual coelom present but reduced to vestiges around the hearts, gonads, and metanephridia (kidney-like organs). The body is divided into a head, often with eyes or tentacles, a muscular foot and a visceral mass housing the organs. Covering the body is a thick sheet called the mantle, which in most forms secretes a calcareous shell. Mollusks have a mantle, which is a shell-like outer cover, and a muscular foot that is used for motion. Many mollusks have their mantle produce a calcium carbonate external shell and their gill extracts oxygen from the water and disposes waste. All species of the phylum Mollusca have a complete digestive tract that starts from the mouth to the anus. Many have a radula, mostly composed of chitin, in the mouth, which allows then to scrape food from the surface by sliding back and forth. Mollusks also have a coelom, made from cell masses, where all organs are suspended. Unlike Coelomates, mollusks lack body segmentation. Development passes through one or two trocophore stages, one of which (the veliger) is unique to the group. These suggest a close relationship between the mollusks and various other protostomes, notably the Annelids. Mollusks:  Mollusks Bivalves:  Bivalves The bivalves are the second largest class of molluscs. They differ from snails in having two shells, usually mirror images of each other. Some like oysters and mussels live attached to rocks and other hard surfaces while others, like pipis, burrow in sand. Leptonoidean bivalves (in picture) are a group which usually live commensally with other animals. Most have a large foot and are active crawlers. :  The bivalves are the second largest class of molluscs. They differ from snails in having two shells, usually mirror images of each other. Some like oysters and mussels live attached to rocks and other hard surfaces while others, like pipis, burrow in sand. Leptonoidean bivalves (in picture) are a group which usually live commensally with other animals. Most have a large foot and are active crawlers. Limatula strangei. Some bivalves, such as the scallops are able to actively move when endangered by vigorously flapping their shells and squirting out jets of water. Limatula also moves very vigorously when disturbed. The tentacles around the mantle edge are sticky, very mobile and parts can break off them when the animal is disturbed, leaving a potential predator with a sticky writhing worm-like object to deal with as the Limatula escapes (25mm).:  Limatula strangei. Some bivalves, such as the scallops are able to actively move when endangered by vigorously flapping their shells and squirting out jets of water. Limatula also moves very vigorously when disturbed. The tentacles around the mantle edge are sticky, very mobile and parts can break off them when the animal is disturbed, leaving a potential predator with a sticky writhing worm-like object to deal with as the Limatula escapes (25mm). Octopus:  Octopus Hapalochlaena fasciata. There are a number of species of blue-ringed octopus in Australian waters. They are all dangerous to handle, as the poison they use to kill their prey (crabs, snails) is highly venomous to humans. This species is common in New South Wales. Usually a dull mottled colour, it can become yellow with bright blue markings when disturbed.:  Hapalochlaena fasciata. There are a number of species of blue-ringed octopus in Australian waters. They are all dangerous to handle, as the poison they use to kill their prey (crabs, snails) is highly venomous to humans. This species is common in New South Wales. Usually a dull mottled colour, it can become yellow with bright blue markings when disturbed. Squid:  Squid Tunafish:  Tunafish Swordfish:  Swordfish 2. FOODBORNE DISEASES FROM SEAFOOD:  2. FOODBORNE DISEASES FROM SEAFOOD raw shellfish or undercooked, smoked, lightly salted fishery products shellfish: sedentary animals ~ filter their food from coastal and estuar waters ~ often subject to pollution by sewage effluents and rain runoff from agricultural lands ~ bacteria, chemical contaminants are concentrated in shellfish ~ quality of shellfish .~ quality of estuarine water in which they have been harvested . finfish: prevalance of hazards higher in coastal and inland aquaculture post-harvest handling, processing Paragonimiasis endemic in Asia, South America, West Aftica snails (first) ~ crustaceans (second) ~ humans, mammals parasite infects the lungs (tuberculosis) B. Nematodiases intemediate hosts marine or ftesh-water fish definitive hosts: marine mammals, birds, pigs mode of infection: ingestion of fish infective larvae Capillariasis - gastroenteritis ~ may be fatal - migratory fish-eating birds ~ natural definitive hosts ~ spread faeces contaminated with parasite eggs in freshwater fish ponds along migratory routes - treatment: mebendazole 400 mg/day for 20-30 days Anisaldasis :  Paragonimiasis endemic in Asia, South America, West Aftica snails (first) ~ crustaceans (second) ~ humans, mammals parasite infects the lungs (tuberculosis) B. Nematodiases intemediate hosts marine or ftesh-water fish definitive hosts: marine mammals, birds, pigs mode of infection: ingestion of fish infective larvae Capillariasis - gastroenteritis ~ may be fatal - migratory fish-eating birds ~ natural definitive hosts ~ spread faeces contaminated with parasite eggs in freshwater fish ponds along migratory routes - treatment: mebendazole 400 mg/day for 20-30 days Anisaldasis C Cestodiases in humans fishborne infections not common Diphyllobothriasis - D. latum: mainly in cold waters (Eastern Europe, USA) - humans and fish-eating mammals: definitive" hosts - fish: intennediate hosts (salmon) - treatment: praziquantel, niclosamide :  C Cestodiases in humans fishborne infections not common Diphyllobothriasis - D. latum: mainly in cold waters (Eastern Europe, USA) - humans and fish-eating mammals: definitive" hosts - fish: intennediate hosts (salmon) - treatment: praziquantel, niclosamide ~ Bacteria divided into two groups: naturally present in the aquatic environment (indigenous bacteria) present as a result of contamination with human or animai faeces contamination during post-harvest handling and processing Enterobacteriaceae introduced into aquaculture ponds by animaI manure or human waste ~ significant numbers in products from waste- fed systems - Salmonella: may be naturally present in some tropical aquatic environment aquatic birds spread them fishborne human infeétions rare strains isolated from humans are different from those found in products from aquaculture - E. coli : bovine manure as pond fertilizer ~ pathogenic strains into the pond water 0157:H7 ~ cattle ~ waterborne infection:  ~ Bacteria divided into two groups: naturally present in the aquatic environment (indigenous bacteria) present as a result of contamination with human or animai faeces contamination during post-harvest handling and processing Enterobacteriaceae introduced into aquaculture ponds by animaI manure or human waste ~ significant numbers in products from waste- fed systems - Salmonella: may be naturally present in some tropical aquatic environment aquatic birds spread them fishborne human infeétions rare strains isolated from humans are different from those found in products from aquaculture - E. coli : bovine manure as pond fertilizer ~ pathogenic strains into the pond water 0157:H7 ~ cattle ~ waterborne infection Shigella: occasionally, very little risk Campylobacter: little information on the occurrence in aquaculture use of poultry manure for fertilizing ponds ~ potential risk Vibrio spp. Salt-tolerant organisms ~ occour naturally in marine environments in both tropical and temperate regions V. cholerae also occours in fresh water frequently isolated from sediments, plankton, molluscs, finfish, crustaceans positive correlation with admixture of contaminated human waste 12 species associated with seefood some human pathogenic Vibrio spp. may also be fish pathogens :  Shigella: occasionally, very little risk Campylobacter: little information on the occurrence in aquaculture use of poultry manure for fertilizing ponds ~ potential risk Vibrio spp. Salt-tolerant organisms ~ occour naturally in marine environments in both tropical and temperate regions V. cholerae also occours in fresh water frequently isolated from sediments, plankton, molluscs, finfish, crustaceans positive correlation with admixture of contaminated human waste 12 species associated with seefood some human pathogenic Vibrio spp. may also be fish pathogens V. Parahaemolyticus ~ particularly associated with consumption of raw marine crustaceans and fish Aeromonas part of the normal aquatic flora A. hydrophila ~ fishbome disease' ~ risk is low :  V. Parahaemolyticus ~ particularly associated with consumption of raw marine crustaceans and fish Aeromonas part of the normal aquatic flora A. hydrophila ~ fishbome disease' ~ risk is low Clostridium botulinum anaerobic, neurotoxin-producing organisms seven types ~ type E is naturally found in aquatic ~environments ~ often isolated from fish prevention of toxin production Listeria monocytogenes frequently isolated from aquaculture products in temperate regions risk: raw or without heat treatment :  Clostridium botulinum anaerobic, neurotoxin-producing organisms seven types ~ type E is naturally found in aquatic ~environments ~ often isolated from fish prevention of toxin production Listeria monocytogenes frequently isolated from aquaculture products in temperate regions risk: raw or without heat treatment Viruses Viruses causing disease in fish are not pathogenic to humans transmission of enteric virus diseases through waste-water reuse systems is far not so important as bacterial or helminthic diseases :  Viruses Viruses causing disease in fish are not pathogenic to humans transmission of enteric virus diseases through waste-water reuse systems is far not so important as bacterial or helminthic diseases Other biological hazards large number of toxic compounds produced by aquatic organisms can cause human diseases produced by aquatic microorganisms: algae, bacteria that serve as food for the larvae of commercially important crustaceans and finfish possible sources of infection in farmed finfish and crustaceans: ingestion of toxic microorganisms or toxic products in feed marine zootoxins are among the most highly toxic substances known: :  Other biological hazards large number of toxic compounds produced by aquatic organisms can cause human diseases produced by aquatic microorganisms: algae, bacteria that serve as food for the larvae of commercially important crustaceans and finfish possible sources of infection in farmed finfish and crustaceans: ingestion of toxic microorganisms or toxic products in feed marine zootoxins are among the most highly toxic substances known: Toxin LD50 (micro g/kg) in mice (IP) Ciguatoxin 0.5 Saxitoxin 3.0 Tetrodotoxin 8.0 Botulinum A 0.0001 TCDD 2.0 :  Toxin LD50 (micro g/kg) in mice (IP) Ciguatoxin 0.5 Saxitoxin 3.0 Tetrodotoxin 8.0 Botulinum A 0.0001 TCDD 2.0 A. Ciguatera poisoning produced by dinoflagellate algae small fish feed algae ~ eaten by larger predatory fish annually 10,000-50,000 cases (USA ~ Florida, Hawaii) mostly due to group er, red snapper, Sphyraena barracuda ciguatoxin accumulates in the liver, intestines, reproductive organs and muscles of the fish Cats are particularly sensitive ~ indicator Prevention difficult: ciguatoxin fish do not appear or taste spoiled :  A. Ciguatera poisoning produced by dinoflagellate algae small fish feed algae ~ eaten by larger predatory fish annually 10,000-50,000 cases (USA ~ Florida, Hawaii) mostly due to group er, red snapper, Sphyraena barracuda ciguatoxin accumulates in the liver, intestines, reproductive organs and muscles of the fish Cats are particularly sensitive ~ indicator Prevention difficult: ciguatoxin fish do not appear or taste spoiled B. Saxitoxin poisoning (paralytic shellfish poisoning, PSP) Saxitoxin: produced by toxic dinoflagellates ~ food base for millions of marine organisms toxin accumulates in the tissues of bivalve molluscs (mussels, clams, oysters, etc.) ingestion of a single clam, if heavily contaminated ~ can kilI a person Prevention: coastal shellfish monitoring programs ~ prohibit harvest during periods when toxin levels are high ("bIoom") :  B. Saxitoxin poisoning (paralytic shellfish poisoning, PSP) Saxitoxin: produced by toxic dinoflagellates ~ food base for millions of marine organisms toxin accumulates in the tissues of bivalve molluscs (mussels, clams, oysters, etc.) ingestion of a single clam, if heavily contaminated ~ can kilI a person Prevention: coastal shellfish monitoring programs ~ prohibit harvest during periods when toxin levels are high ("bIoom") C Tetrodotoxin poisoning (Puffer fish poisoning) Many species of puffer fish ~ tetrodotoxin Major cause offatal food poisoning in Japan (fugu) (Captain Cook nearly died of tetrodotoxin poisoning in New Caledonia in 1774) Tetrodotoxin: potent vasopressor and neurotoxin concentrates in the liver, skin ~ flesh becomes contaminated while the fish is cleaned Dogs, cats and birds are also susceptible :  C Tetrodotoxin poisoning (Puffer fish poisoning) Many species of puffer fish ~ tetrodotoxin Major cause offatal food poisoning in Japan (fugu) (Captain Cook nearly died of tetrodotoxin poisoning in New Caledonia in 1774) Tetrodotoxin: potent vasopressor and neurotoxin concentrates in the liver, skin ~ flesh becomes contaminated while the fish is cleaned Dogs, cats and birds are also susceptible D. Histamine Due to ingestion of spoiled fish -) mostly Scombroidae (eg, tuna, machereI) develops post-mortem due to improper handling and inadequate refrigeration tissues of scromboid fish contains high level of histidine -). histamine (Vibrio, Klebsiella, etc.) Histamine degraded orally - cadaverine and putrescine (cocontaminants) inhibit histaminases in human intestine Levels > 50mg histamine / 100 g of flesh ~ hazardous :  D. Histamine Due to ingestion of spoiled fish -) mostly Scombroidae (eg, tuna, machereI) develops post-mortem due to improper handling and inadequate refrigeration tissues of scromboid fish contains high level of histidine -). histamine (Vibrio, Klebsiella, etc.) Histamine degraded orally - cadaverine and putrescine (cocontaminants) inhibit histaminases in human intestine Levels > 50mg histamine / 100 g of flesh ~ hazardous 4. CHEMICAL HAZARDS Through exposure to compounds used in the aquaculture systems or by pollution of waterways or sources of water:  4. CHEMICAL HAZARDS Through exposure to compounds used in the aquaculture systems or by pollution of waterways or sources of water A. Agrochemicals Fertilizers (urea, ammon ion, salts, trace element mixes) ~ usually no risk to food safety when used according to good agricultural practice Water treatment compounds (lime, oxidizing agents, flocculants)~ non-hazardous Pesticides (algicides, herbicides) no major risk disinfectants ~ widely used ~ no risk to consumer chemotherapeutica (antimicrobials, parasiticides) . drugs approved . drug residues :  A. Agrochemicals Fertilizers (urea, ammon ion, salts, trace element mixes) ~ usually no risk to food safety when used according to good agricultural practice Water treatment compounds (lime, oxidizing agents, flocculants)~ non-hazardous Pesticides (algicides, herbicides) no major risk disinfectants ~ widely used ~ no risk to consumer chemotherapeutica (antimicrobials, parasiticides) . drugs approved . drug residues - Metals (Pb, Cd, Cu, Zn, Fe ) present as a result of geochemical processes result of pollution pH of the water pollutants Mercury Chlorinated compounds (DDT, PCBs, dioxins) :  - Metals (Pb, Cd, Cu, Zn, Fe ) present as a result of geochemical processes result of pollution pH of the water pollutants Mercury Chlorinated compounds (DDT, PCBs, dioxins) 5. CONTROL OF FOODBORNE DISEASE FROM SEEFOOD Fish · must be washed and chilled in ice or in cold water immediatley after catching · all of the ship equipment use for fish chilling must be c1eaned and disinfected after each debarkation · fish must be eviscerated as quickly as possible · chilling is also required during transportation to port and during distribution for further pocessing · thorough washing is very important ~ removes up to 95% of putrefactive microorganisms present on the fish skin · during transportation for long distances, the water must be aired; optimum temperature 4-80 oC :  5. CONTROL OF FOODBORNE DISEASE FROM SEEFOOD Fish · must be washed and chilled in ice or in cold water immediatley after catching · all of the ship equipment use for fish chilling must be c1eaned and disinfected after each debarkation · fish must be eviscerated as quickly as possible · chilling is also required during transportation to port and during distribution for further pocessing · thorough washing is very important ~ removes up to 95% of putrefactive microorganisms present on the fish skin · during transportation for long distances, the water must be aired; optimum temperature 4-80 oC Shellfish environmental monitoring of water quality US Public Health Service: shellfish growing areas are surveyed for safety ~ only those waters not subject to sewage contamination and havingcoliform counts <: 70 organisms/100 ml are approved for harvesting shellfish transferred from marginally polluted areas to unpolluted waters and left min. 14-28 days ~ will purify themselves (depuration) public education about the risks associated with eating raw shell fish :  Shellfish environmental monitoring of water quality US Public Health Service: shellfish growing areas are surveyed for safety ~ only those waters not subject to sewage contamination and havingcoliform counts <: 70 organisms/100 ml are approved for harvesting shellfish transferred from marginally polluted areas to unpolluted waters and left min. 14-28 days ~ will purify themselves (depuration) public education about the risks associated with eating raw shell fish pH of fish meat = 6.8 - 7.0 H2S (lead acetate) at 50 oC free ammonia trimethil-amine histamine - below 100 ppm :  pH of fish meat = 6.8 - 7.0 H2S (lead acetate) at 50 oC free ammonia trimethil-amine histamine - below 100 ppm

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