Handling of fish on-board

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Handling of fish on-board
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
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Content

• Video about handling on-board
• Current practices and improvements
• Handling of tuna on-board

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Learning objectives

• After this lecture the participants will have
• an overview of the situation in Sri Lanka
  regarding handling on board
• ideas on how to improve the situation

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Video

• Handling of fish on-board
• - UK -

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Current practices

• Fish is put in hold at sea temperature
• Fish is stored loose in hold (pressure on fish in
  lower layers)
• Fish is cooled with crushed block ice or flake
  ice
• Handling time on deck is long (in heat)
• Gutting and bleeding usually not practised

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Video
Storing fish in the hold
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Possible improvements

• Put fish into ice slurry in an insulated tub
  after catch
• for cooling down fast
• for bleeding
• Put cold fish into boxes in hold
• easier handling
• less pressure on lower layers
• possible to use day markings

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Manual transport equipment
Sack or case truck
Hand-drawn truck
Hand pallet truck
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Cooling rates in the center of cod - comparison
of flake ice and liquid ice
Temp. (C)
Time (hours)
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Cooling /keeping cool

• Ice slurry is good for cooling fish down quickly
• compleatly surrounds the fish
• good heat transfer
• Flake ice is good for keeping fish cool
• keeps fish moist while melting
• blood water and slime is washed off
• This may require less ice than the current
  practices and give much better quality fish

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Video
Small boat in Reykjavik harbour
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• PRE-HANDLING AND HOLDING METHODS FOR OCEAN TUNA

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Content of this lecture

• The importance of handling and storage of ocean
  tuna
• Diagram of handling and storage of raw material

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COMMON SPECIES OF OCEAN TUNA IN SRI LANKA
Big eye tuna
Yellow fin tuna
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The importance of pre-handling and holding of
ocean tuna

• Assure good quality of raw material
• Prevention of histamine formation

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Maintain quality of raw ocean tuna
If catching, pre-handling and holding is not done
properly
Appearance will be changed
Colour and flavour of flesh can be changed
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The importance of handling and holding of ocean
tuna (Continued)
Histamine
Histidine
Histamine
Histidine decacboxylaza
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Diagram of HANDLING and holding of OCEAN TUNA

• Catching, gaffing and landing
• ?
• Killing
• ?
• Bleeding
• ?
• Gutting
• ?
• Cleaning
• ?
• On-board storage

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CATCHING, GAFFING AND LANDING THE FISH

• Always gaff the fish through the head.
• Use two gaffs for big fish, the second through
  the mouth
• It is advisable to lift the fish tail to help
  haul it on-board
• Carry out all subsequent handling on a foam pad

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KILLING THE NEWLY- LANDED TUNA

• Once aboard, the fish should be killed immediately

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Bleeding
Bleeding the tuna by making a cut in the side of
the fish with a knife, five to ten centimeters
behind the base of pectoral fin recess, on both
sides of the fish. Blood should flow freely from
these cuts.
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GUTTING OF FISH

• The gutting of fish can bring about the following
  advantages
• Make subsequent chilling more effective
• Remove undesirable digestive enzymes
• Prevent undesirable bacteria in the fish
  intestine from spreading
• Avoid the penetration of parasites such as
  nematodes from the gut into the flesh

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Cleaning of fish
Scrub the inside of the abdominal cavity without
removing the white membrane which covers the
backbone. Carefully rinse the fish, inside and
outside. The fish is now ready to be placed in
brine or ice.
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ON-BOARD STORAGE
It is recommended to use the two following staged
procedure to obtain a top-quality fish (like in
pre-handling of raw materials).
Lower the internal temperature of the fish by
placing it in chilled brine (a slurry of crushed
ice and seawater). After the core temperature
reaches 0C, put the fish in ice and keep it
there until arrival at port.
Alternatively, the tuna can be iced directly to
reduce temperature. However this method takes
longer time
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On-board storage
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UNLOADING of fish
The following rules are important during loading
Do not twist the fish when removing them from
the ice. They should be held by the head rather
than the tail. Handling the fish gently. Do
not leave the fish too long in the open air or
sunlight.
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References

1. Training materials on catching and on-board
   handling of ocean tuna. Pacific Ocean
   Organisation.
2. INFOFISH (1999)
3. Hall, G.M (1997). Fish Processing Technology
4. Scombroid Poisoning. FDA (1999)
5. FDA (2003)