B.K.Kolita Kamal Jinadasa,Research Officer,

Post Harvest Technology Division,NARA

Our Resources:

Land area 65,610 Km2

Sea area 517,000 Km2 (Land area x 8)

Territorial water

21,500Km2

Continental shelf area

30,000 Km2

Brackish water area

158,016 ha

Freshwater area

260,000 ha

Coastal line 1,620 Km

Number of rivers

103

Collective length of rivers

460 Km

Contribution GDP - 2007

1.5%

Donation to GDP- Top 10 Countries

Capture fisheries GDP contribution %

Aquaculture GDP contribution %

Kiribathee 36.17 Laos 6.33Marshal Islands 24.77 Vietnam 5.17Maldives 19.31 Bangladesh 2.34Wanatu 18.89 China 2.10Solaman Islands 11.05 Myanmar 1.24Kamboj 7.88 Thailand 1.02Pillipines 2.22 Indonesia 0.84Tango 2.15 Philippines 0.77Indonesia 1.84 India 0.44Bangladesh 1.76 Nepal 0.39Myanmar 1.72 New Zealand 0.32Sri Lanka 1.28 Sri Lanka 0.19Source: status and potential fisheries & aquaculture in Asia & Pacific - FAO

Our Export & Import (2007)Export Import

Type Quantity (MT)

Value (Rs. Million)

Type Quantity (MT)

Value (Rs. Million)

Prawns 2023 2487 Maldives fish

3651 651

Lobster 184 352 Dried fish 48092 5602

Crabs 1151 575 Canned fish

23105 3740

Beach-De-Mar

208 445 Fresh fish 10846 1815

Chank & cells

564 906 Other fishery products

462 153

Shark fins 67 145

Mollusks 713 127

Fish 15473 13567

Common fishing gear…• 1. Net

– Gill net– Trawl– Purse seine– Beach seine

• 2. Line– Trolling– Pole & line– Long line

Beach seine

Pole & Line

Important Marine fish species

For more information…….

Or U can go to:www.fishbase.org

Yellow fin tuna- Kelawalla, Kenda, Kahawaral kelawalla

Scientific Name: Thunnus albacares

English Name : Yellow fin tuna

Fish with very long second dorsal fin and anal fin, which in some may reach well over 20% of the FL. Color is black metallic dark blue changing through yellow to silver on the belly. The belly frequently has about 20 broken, nearly vertical lines. The dorsal and anal fins and fin lets are bright yellow. Importance: Fisheries: highly commercial.

Skip jack tuna- BalayaScientific Name: Katsuwonus pelamis

English Name : Skipjack tunaBody without scales except for the corselet and the lateral line. The back is dark purplish blue, lower sides and belly silvery, with 4 to six very conspicuous longitudinal dark bands which in live specimens may appear as continuous lines of dark blotches. Importance: fisheries, highly commercial.

Kawakawa – Atawalla, Ragoduwa

• Family: Scombridae (Mackerels, tunas, bonitos). • Common names: Ragoduva,Atavalla, Sureya.• Max. size: 100.0 cm FL.• Max. published weight: 14.0 kg.• Posterior portion of the back with a pattern of broken

oblique stripes. • Importance: fisheries: highly commercial.

Skip jack tuna- BalayaScientific Name: Katsuwonus pelamis

English Name : Skipjack tunaBody without scales except for the corselet and the lateral line. The back is dark purplish blue, lower sides and belly silvery, with 4 to six very conspicuous longitudinal dark bands which in live specimens may appear as continuous lines of dark blotches. Importance: fisheries, highly commercial.

Sail fish- Thalapatha• Scientific Name: Istiophorus platypterus

• English Name : Indo- Pacific sail fish• Upper jaw like spear.• Sail-like first dorsal fin.• Vertically nearly 20 Light blue dot lines in the

body.Importance: fisheries: commercial.

Sward fish - Kadukoppara• Blackish-brown fading to light-brown

below.• 1st dorsal fin with blackish-brown

membrane, other fins brown or blackish-brown .

• A long, flat, sword-like bill and no pelvic fins.

• Global Importance: Fisheries: commercial.

Black Marlin – Kalu koppara, Sappara

• upper jaw produced into a robust but not very long beak; two dorsal fins

• 1st dorsal fin blackish to dark blue, other fins dark brown with tinges of dark blue in some specimens. Anterior part of dorsal fin shorter than body depth

• Importance: fisheries: commercial

What is fish?Classification

Fish are generally defined as aquatic vertebrates that use gills to obtain oxygen from water and have fins with variable number of skeletal elements called fin rays (Thurman and Webber, 1984).

Five vertebrate classes have species which could be called fish, but only two of these groups - the sharks and rays, and the bony fish - are generally important and widely distributed in the aquatic environment

Scientific grouping Biological characteristics

Technological characteristics Examples

Cyclostomes jawless fish lampreys, slime-eels

Chondrichthyes cartilaginous fish high urea content in muscle sharks, skate, rays

Teleostei or bony fish pelagic fish fatty fish (store lipids in body tissue)

herring, mackerel, sardine tuna, sprat

demersal fish lean (white) fish (store lipids in liver only)

cod, haddock, hake grouper, seabass

• It is important for the food processor, the nutrionist and the consumers to know the composition of particular food so to help each of them answer question that they may have.

• The normal variations in the principle constituents in fish muscles are;– 16%-21% protein.– 0.2%-25% fat.– Less than 0.5% carbohydrate.– 1.2%-1.5% ash.– 66%-81% moisture.

Marine fish Vs. Freshwater fishMoisture % Ash% Lipid% Protein%

Halmessa 78.4 3.8 1.2 15.2

Hendella 78.4 3.3 1.3 15.9

Salaya 73.3 4.5 1.8 17.5

Hurulla 74.3 2.7 1.4 17.4

Linna 72.1 3.1 3.3 10.1Tuna 71 _ 4.1 25.2

Carp 81.6 _ 2.1 16.0

Eel 65.5 _ 19.5 14.4

Omega - 3They are essential nutrients just like the vitamins and minerals as our body cannot make them and they play many critical roles. Omega-3s are a type of polyunsaturated fat. The Omega-3 (called ALA) found in plant sourced foods such as canola oil, linseeds and walnuts needs to be converted by the body to the long chain Omega-3s to be used effectively. Unfortunately this conversion is very inefficient so it is desirable to include long chain Omega-3s in the diet as well. These are found in oily fish, other fish and seafood and to a lesser extent in meats and eggs. Foods enriched with long chain Omega-3s are beginning to appear in supermarkets. Supplements of fish oil are rich in long chain Omega-3s.

Total long chain Omega-3 content of some common foods

Sea foods mg/100g Other foods mg/100gKing salmon >2000 Eggs regular 80Green shell /lipped mussels

950 Turkey 30

Hoki (Blue grenadier)

410 Beef 20

Gem fish 400 Milk regular 0Blue eye cod 310 Vegetable oils & spreads 0

Sydney rock oysters

300 Regular bread 0

Tuna canned 230 Cereals, rice, pasta, etc 0

Snapper 220 Fruit 0Barramundi saltwater

100 Vegetables 0

Giant tiger prawn

100

On boat Handling:1. Land fish gently & quickly

handle fish gently to reduce brushing & internal bleeding, avoid gaffing if possible, if use gaff, place it in the head of fish.

but in our practice……..

• 2. Stunning or brain spiking-– Stun the fish with a sharp blow to the head

using club or mallet. Stunning makes fish easier to handle & prevents brushing and internal bleeding.

• 3. Bleeding & eviscerate:– Bleed fish by cutting throat to server the

artery between gills & heart. Gut the fish after bleeding (not possible in small species)

• 4. Chill and pack (normally putting 15 min) & transfer to the storage place

• 5. Quick landing

Chilling, Icing & freezing• Chilling is the process of cooling fish or fish products to a

temperature approaching that of melting ice.• Methods of Chilling:

Flake iceBlock ice and crushed block iceTube iceIce slurryLiquid iceChilled seawaterRefrigerated seawaterDry or gel ice

Types of ICE• Flake ice:

– Made by the “free-flow” technique resulting in thin layers of ice at sub-zero temperature.

– Gives good ice-fish contact because of its large surface area.– Tends to form clumps, making it impractical.– Melts very rapidly.– Useful for cooling a product down quickly.

• Tube ice:– Cut from long, hollow tubes of ice formed inside refrigerated pipes of

small diameter.– The cylindrical shape is not practical for icing.– Lasts longer and melts more evenly than other shaped ice.– Useful for transporting fish in uninsulated containers.– More likely to bruise fish because of its large size.

• Crushed ice:– Has sharp edges and irregular sizes.– Causes bad indentations on the fish body.– Effects poor heat transfer due to air pockets.– If used, individual piece should not be larger than 2.5 cm.

• Block ice:– Usually are large and heavy.– Must be crushed into smaller pieces.

• Ice slurry:– Flake or block ice crushed to small ice particles and mixed with

seawater or water.– Good for cooling.– Not as good for keeping cool unless drained

• Stagnant blood water.• Salt update

• Liquid ice:– Very small ice particles form in salt water/sea water.– Very good cooling properties.– Not as good for keeping cool unless drained.

• Chilled seawater (CSW):– Seawater & ice mixed in a container or hold (ice : seawater= 2:1 ratio);

• Agitated by blowing air up through the mixture.– Good for quick cooling.– Salt uptake can be problem in fish is in CSW for long time.

• Refrigerated seawater (RSW)– Seawater cooled by mechanical means, seawater is circulated from fish

container/hold, through a refrigerating unit and back to the container/hold.

– Maintain temperature -1 to -5 C. (seawater : freshwater = 80-90% : 10-20%)

– Good for quick cooling.

Chilling & Icing

Flake Ice

Immersion in ice for killingIce slurry

When use CSW or RSW for chilling fish, the fish should be put in a mutton cloth sock to protect the skin from chaffing.

Cooling rates in the center of cod -comparison of flake ice and liquid ice

Tem

p. (°

C)

Time (hours)

Flake ice

Liquid ice

Fast FreezingFast FreezingSlowSlow FreezingFreezing

Type of freezer

• 1. Air blast freezer– Blowing a continuous stream of cold air

over the fish– Operating temperature -35 to 40 C

• 2. Contact or plate freezer– Direct contact between the fish and

refrigerant surface.– Operating temperature -45 C.

Air blast freezer

Plate freezer

Icing Vs Freezing Amount of ice – cooling fish100 kg of fatty fish at 25°C needs to be cooled to 0°C with ice

- 1 kg of ice can take up 80 kcal og heat when melting

- to cool 1 kg of fatty fish by 1°C 0,78kcal have to be removed

How much heat to remove?

100kg * 25 °C * 0,78 kcal/kg °C = 2610 kcal

How much ice will that melt?

2610 kcal / 80 [kcal/kg ice] = 32.6 kg of ice

OR ABOUT 1 KG ICE per 3 KG FISHVideo

RECOMMENDED DOMESTIC STORAGE TIMES

Fish Refrigerator Freezer

White fish I -2 days 3 months

Oil-rich fish 1 -2 days up to 2 months

Smoked fish 2-3 days up to 3 months

Shellfish I -2 days I month

Cooked fish I -2 days 2 months

Our Harbor practices…

But, compare with others… Our fish market…………………

Our regulation????• Gazette No 1045/01 – 14th sep 1998.• Fish stall:

– Should cover, easy to clean wall– Flow should be easy to clean– Toilet, towel, detergent– Prevent the enter animals, vehicle– Avoid smoking, eating,….

• Landing:– Easy to clean– Quickly landing– Adequate icing

Identification of fresh fish

• Clear, bright eyes, not sunken • Bright red gills • Scales should not be missing and they should

be firmly attached to the skin • Moist skin. Really fresh fish feels slightly

slippery • Shiny skin with bright natural coloring • Tail should be stiff and the flesh feel firm • It should have a sea-fresh smell

Post harvest changes of fish

• How to fish go bad,– endogenous enzymes – exogenous bacterial activity– autolysis

• “freshness of fish” includes;– Enzymatic freshness:

• Lowering of freshness by autolytic action of fish tissue enzyme.

– Bacterial freshness:• Lowering of freshness by exogenous enzymes

secreted by bacteria.

Endogenous changes influencing fish quality at post mortem.

• Rigor mortis.• Autolysis.• Pigment changes in skin, meat and gills.

Rigor mortis• What is rigor mortis?

– It is the stiffening of the muscles of an animal shortly after death.

• How does it occur?– Rigor in fish usually start at the tail, and the muscles

harden gradually along the body towards the head until the whole fish is quite stiff.

– The fish remains rigid for a period which may vary from an hour or so to three days or more, and then soften again.

• Video Rigor mortis @ different temperature

Freshness indicators of fish• Sensory evaluation/taste panel• Organoleptic test

– Eyes are bright and clear/cloudy, gills are pink & fresh/ brown, skin is shiny/ slimy, flesh is firm/soft

• Chemical analysis• TVN, ATP, Histamine, Heavy metals (HG, Cd,

Pb), chemical residues• Microbiological analysis

– Total plate count, Pathogenic bacteria

Histamine Detoxification

Presence of BA’s in Tuna fish storage at ambient temperature

(BA’s in mg/kg and Time in Hours)

Histamine in one day and multi day boats

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Fish at Sea Fish at Harbour before washing Fish at Market

mg/

kg

1 day (trip 2)1 day (trip 3)7 days (trip 5)8 days (trip 1)9 days (trip 6)15 days (trip 4)

Histamine Legislation

• A level less than 5mg/100g (50ppm)is safe for consumption

• Maximum level of histamine have set at 10-20mg/100g in many countries

• Levels above 50mg/100g is a hazard action level, unsafe for consumption

• Different countries have set different levels as regulatory limits

Effects of histamine

Thank you!Thank you!