Seafood hygiene Flashcards
Which country produces the most fish worldwide?
China produces the most fish.
Egg, pork, etc.
Name the two categories of fish
Fish
Shellfish
Shellfish are divided into two categories. What are they?
Crustaceans and Molluscs.
What is a major difference between crustaceans and molluscs?
Crustaceans have jointed legs
Molluscs are _____ feeders; _____ everything, even ____ and _____. They are considered to be the most _______ animals due to their filtering abilities.
Molluscs are filter feeders; trap everything, even toxins and viruses. They are considered to be the most contaminated animals due to their filtering abilities.
What other animals fall under the category of fish as per US legislation?
AFAJSSM
“JAMS Are Sexy Frogs”
a. alligator
b. frog
c. aquatic turtle
d. jellyfish
e. sea cucumbers
f. sea urchin
g. molluscs
Name the unique features of the muscles of fish
Fish muscle contains little _______ tissue (2?) and ____ levels of water (____%)
✓ Bacterial growth in between ________.
✓ Bacteria movement within fish _____
✓ rapid __________ deterioration of the tissue
✓ _______ shelf life.
✓ Since fish spoils more readily, regularly stored on ________ ____ (____°C)
Fish muscle contains little connective tissue (collagen, elastin) and high levels of water (80%)
✓ Bacterial growth in between muscles.
✓ Bacteria movement within fish flesh
✓ rapid microbiological deterioration of the tissue
✓ short shelf life.
✓ Since fish spoils more readily, regularly stored on melting ice (~0°C)
____ degree Temperature danger zone does not work for fish, must reduce to ____.
4 degree Temperature danger zone does not work for fish, must reduce to 0
Fish glycogen content is very _____. Glycogen is necessary for meat hygiene because it produces ____ _____ that _____ bacteria and makes environment ________ for bacteria.
Fish glycogen content is very low. Glycogen is necessary for meat hygiene because it produces lactic acid that kills bacteria and makes environment unsuitable for bacteria.
Fish ph = ?
> 6.0 b/c of low glycogen
There are a lot of freely available amino acids, such as histidine. What is the purpose of this for bacteria?
Their food is readily available for free food so they can eat.
No work needed to eat.
Seafood muscle or flesh is therefore too much susceptible to spoilage compared to terrestrial animals.
Muscle is also high in trimethylamine oxide, Urea, creatinine phosphate stored as ATP.
What are the four steps of the seafood supply chain?
What is a fishery?
Fish home is water bodies.
Fisheries = farm = waterbodies
The supply chain for fish is short. Why?
Because it spoils very quickly.
In broiler chickens, when do they go to slaughter?
1 month
Fish reach slaughter at what age?
2 years, even 3 sometimes
Most fish, like shellfish, muscle, shrimps, oysters like?
salt water
Cat fish and trout like what type of water?
fresh water - rivers, ponds, lakes
Fish need 5 AW principles and good hygienic practices. What are they?
- Good hygienic/agricultural practices in fisheries
- five pillars of animal welfare
➢ feed
➢ water
➢ health
➢ space
➢ avoid fear
➢ social behavior
___________ bacterial can turn against fish and make them sick.
Environmental bacteria
- Soil borne diseases:
_________ Eat decaying matter with bacteria: (saprotroph - decaying)
Viruses from terrestrial animals
_______ organisms rely on fish to survive.
Commensal bacterial can turn against fish and make them sick.
Environmental bacteria
- Soil borne diseases: Listeria Eat decaying matter with bacteria: (saprotroph - decaying)
Viruses from terrestrial animals
Sympatic organisms rely on fish to survive.
List some examples of aquatic commensal bacteria.
PAVE My Cute P*ssy
Pseudomonas
Vibiro
Aeromonas = aquatic organisms
- rely on fish to survive = commensal
clostridum botulinum = water
eryspleothrix
Pasteurella
mycobacterium
= commensals that turns against fish when welfare is compromised
Which bacterium is found in soil that can compromise fish?
Clostridium Perfringens = soil
List some examples of enteric viruses that attack fish.
Enteric viruses - terrestrial animals: noro, rota
- Enterobacteriacae = salmonella, e.coli, klebsiella, enerobactera, yersinia, morgenella, etc. shigella
- campylobacter and staph –> terrestrial and attack fish
List nematodes that attack fish
Nematodes:
1. Anasachis worm
List the trematodes that attack fish
Trematodes:
2. Clonorichis –> zoonotic –> liver cancer in humans
3. Opistorchis –> zoonotic –> liver cancer in humans
List the tapeworms that attack fish
Tapeworm: D. buthrium
List the protozoa that attack fish
Protozoa: Giardia, crypto
What is the fish processing line at a fish slaughterhouse?
See below
Fish handling during ante mortem & post-mortem
✓ Fasting (starvation) of prior to slaughter reduces the amount of feces in the intestines and delays spoilage.
*
✓ In general, the fasting period is 1–3 days
1. Remove 5D fish from supply i. e. slaughter only healthy fish
* Harvesting, stunning & killing methods greatly affect post-mortem changes & subsequent fish carcass quality
Dead, dying, diseased, disabled, drug-residuals
How do we stun fish?
- Legally acceptable to stun the head.
- Tool looks like hammer - Sharp object to pierce the head.
- Suffocate with CO2.
- Pass them through electrified water bathes –> unconscious
How to get jugular vein? Cut gill while unconscious
Gut
Wash
if you want a fresh fish, it should be eaten in?
2-5 days
Shellfish shelf life is?
Chill at 0 degrees.
Eat fish in 2-5 days. Depends on species of fish
Shellfish shelf life is short
Why? They are filter feeders, therefore a lot of stuff is already there
List the sources and causes of spoilage of fish?
- Their own body (due to commensals)
- Shell - Gill
- Gut
- Once dead, bacteria multiply b/c no defense system to arrest their growth.
- Somatic enzymes –> start to pultrify –> rancid formation –> spoilage of meat.
Name the two most important factor in
accelerating fish spoilage
- A rise in temperature above 32°F
- Should be 0 degrees celsius. - Low glycogen in fish flesh (low lactic acid – high pH) → fish flesh favorable for microbial growth
- The four main factors for the source of spoilage at fish slaughterhouses are:
✓ Shucking (de-skinning = shell) & gutting (evisceration)
✓ washing the fish
✓ cleanliness of fishrooms
✓ cleanliness of the ice in which fish is stunned or preserved - Therefore, improve handling, washing the fish and its surroundings on board the trawler, and adequate icin
What are the Four typical spoilage stages due to fish nutrients breakdown by spoilage bacteria?
Bad smell in fish happens during spoilage. Why?
In fish muscle there are freely available AA, urea, histidine, TMA. Once fish is spoiled, what happens in next few days?
1. Rigor mortis
2. Body is not totally sterile, there are pathogens. Pathogens start to eat ATP and convert to Inesine–> hypoxanthine –> xantine and uric acid. Urea and Amines –> ammonia, TMAO –> TMA
Uric acid –> rheumatoid arthritis
If you have gout you are not supposed to eat seafood
H2S –> rotten egg
Fish carry large numbers of bacterial flora from 3 sources.
- Name three examples of Cold loving bacteria:
- Name some examples of microbes that thrive at room temp:
- Name some examples of microbes that thrive at very high temp:
- Listeria, pseudomonia, flavibacteria,
- Enterobacteriacae: salmonella, e.coli, staph aureus.
- baccilus and micrococuccs
Name two microbes that, when fish, are spoiled it changes color.
E.g. pseudomonas changes color of fish to greenish yellow.
E.g. Fungal, micrococcus, Yersinia –> changes to red/pink color.
_______ is a major component associated with the unacceptable odor of fish spoilage. ____ starts to increase in the tissues after 5-10 days.
TMA, TMA
Degradation of proteins produces ________, and________, and _______, which are components used for the chemical detection of fish spoilage.
Degradation of proteins produces total volatile acids, and total volatile bases, ammonia, which are components used for the chemical detection of fish spoilage.
What is the benchmark/characteristic evaluated for human consumption?
Sensory organoleptic evaluation.
How do I know my fish is safe and edible?
- Organoleptic qualities
- color, odor, firmness, etc. - Microbiological
- Parasitological
- Chemical composition
- pH, moisture, fat content, mineral poisoning (mercury, lead) - metabolic products
- TMA
- Ammomia
- H2S
- Histamine
- Tetrodotoxin
- Algal toxin
Normal fish have:
1. Eyes: ______ eye with _____ cornea
2. Gills: Bright ____ or ____ gill with ______
3. Skin: well-_______ colors and is _____ with _____ slime.
4. Odor: ____, _____-like/_______-like or ________
- Eyes: convex eye with clear cornea
- Gills: Bright red or pink gill with mucus
- Skin: well-differentiated colors and is glossy with transparent slime.
- Odor: sharp, sea-like/iodine-like or metallic
Spoiled fish have:
- Eyes: sunken and cloudy with a discolored cornea.
- Gills: bleached and/or discolored and coated with thick slime.
- Skin: loses color, coated with yellow, knotted slime.
- Odor: like stale cabbage-water, sour drains, wet matches or ammoniacal.
➢ The odor of trimethylamine (TMA) dominates i.e. rotten fish smell
Quantitative measurement of total volatile nitrogen — A quality criterion for fish spoilage
Ammonia, TMA, hydrogen sulfide –> measure them and then tell whether fish is contaminated.
Foodborne diseases in USA cause illness in 48 million
…..10-19% of these are by ingestion of ________.
seafood
Shellfish accounted for ____% of the seafood-related
infectious outbreaks and finfish were implicated in ____%.
1. _________ causes gastroenteritis associated with
consumption of raw shellfish, especially oysters
2. 20% of bacterial illnesses related to shellfish
consumption are caused by the ______ species
Shellfish accounted for 64% of the seafood-related
infectious outbreaks and finfish were implicated in 31%.
1. Norovirus causes gastroenteritis associated with
consumption of raw shellfish, especially oysters
2. 20% of bacterial illnesses related to shellfish
consumption are caused by the Vibrio species
Vibrio species are aquatic, which are not a public
health risk from ______ animals.
farm
List the major biological (bacteria, virus, & parasite)
hazards from seafood consumption in the USA
- Major one is vibrio, specifically the species: vibrio parahemolyticus. If removed, significantly removed 20% of the problem
- Norovirus is second
- Salmonella is next
- Listeria
- Anasachis
- Giardia
- tapeworm
________ is most prevalent in shellfish
Vibrio
Vibrio can __________ our limbs due to shock
amputate
Around 50 million people are affected by ________ and _______. Causes:
✓Gall bladder disease in humans
✓ bile duct closure in humans
✓ liver damage &
✓ liver cancer
clonorchia, opistrochis
Seafood not only brings ________ hazards to us but also _________ hazards if we are not farming them under hygienic conditions. These toxins come from?
Seafood not only brings biological hazards to us but also chemical hazards if we are not farming them under hygienic conditions.
Toxins can be from bacteria, fish themselves, Algae –> toxin producing algae accumulates in fish muscle. When we eat, passes to us.
What are the major chemical hazards from seafood consumption
Scombroid toxin/histamine
What kind of toxin is this?
What is the major chemical hazard from seafood consumption?
Scombroid toxin/histamine
Scombroid is a type of _____. The toxin is ________; when released too much –> constricts ______ muscle –> can’t ______.
Scombroid is a type of fish. The toxin is histamine. Histamine is released too much –> constricts smooth muscle –> can’t breathe.
The strongest histamine producers are?
Fish species of the Scombroid family are?
Which scombroid fish are the major source of histamine poisoning?
tuna and mackerel
Scambrdie fish and dolphin fish (aka mahi mahi) (not scombroid but when enterobacteriacae in mahi mahi contaminate scambroid fish –> change histadine to histamine).
Mahi mahi = non scromboid
Bacterioasce contaminate this kind of fish, change histadene to histamine?
To prevent this? Good hygiene, immediately put fihs in 0 degrees celsius so bacteria don’t amplify
Tetrodotoxin (pufferfish toxin)
When pufferfish are contaminated with (3?) –> produces tetrodotoxin –> _______ nerves.
aeromonas, pseudomonas, or vibrio
paralyzes
When pufferfish is contaminated with
1. Aeromonas,
2. Pseudomonas
3. Vibrio species
it produces
Tetrodotoxin
Algal toxins, mostly associated with shellfish except sugatoxin.
What are the 4 toxins from algae that affect shellfish?
- Amnesic
- Domoic Acid - Diarrhetic
- Neurotoxin
- Paralytic
Another toxin, not from shellfish, but from finfish is called ___________, that they get from algae.
Ciguatoxin
How do we preserve seafood post-harvest for
prevention of microbial contamination?
- Cold storage
- Chill whole fish after catching/harvesting, and killing.
- Smoke, dry, salt, cure it if chilling not possible - Toxins are heat stable, so if you cook them they are still active. Be careful with wild fish! Not very common, but still a concern.
