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POST HARVEST FISHERIES

Fish Processing

-includes the diferent processes and techniques employed in post harvest handling,

processing and marketing o aquatic products rom the time o harvest to nal

utilization

Responsible Fisheries Post Harvest and Marketing

-involves optimum utilization o the catch through the use o technologies that will

ensure the sustainable production o quality and sae sh and shery products while

realizing maximum prot to processors.

ish !omposition

Coponent Percenta

ge

"ater

#rotein

at

$inerals %!a, #, e, $g,!u&

'itamins %(,),thiamin, *+, riboavin,

nicotinic acid&

/-0/1

+/-21

+-31

/.+ 4 21

5race

ish !lassication based on lipid content

atty sh 4 has more than 21 lipid

$edium atty sh 4 has -21 lipid

6ean sh 4 has less than 1 lipid

5ypes o ish $uscle

"hite76ight $uscle 4 makes up the bulk o the edible portion8 non-pigmented8

about 0/1 o the muscle

9ed7)ark muscle 4 or dark muscle8 ans out on either side o the lateral line8

color is due to the pigment myoglobin.

- comprises about +/1 o the muscle8 in typical white sh.

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- with high levels o hemoglobin, histidine. lipids and enzymes

- very prone to oxidation

- #elagic species- more dark muscles than demersal 8 up to 3:1

Rational !tili"ation o# Fish Parts $%&kov '()*+

Parts Main Coponents Prod,cts

*ody meat

9oe %eggs&

;kin

*ladder

6iver

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6actic acid- ormed rom glycolysis because o the absence o oxygen.

-dec. p@closer to protein isoelectric pointdecreases water binding capacity

(gents o spoilage

+. F=GA$F; 4 which is either ound in the sh tissues or elaborated bymicroorganisms during growth.8

- endogenous 4 inherent in the organism

- (H5C6A;B;- sel-breakdown or sel-digestion that results to the weakening,

sotening and discoloration o sh tissues

- !athepsins-lysosomal proteases present in sh muscles

. !@F$B!(6 9F(!5BC= 4 that are not mainly due to enzymes, such as lipid

oxidation.

6ipid (utolysis- enzymatic hydrolysis o atty acid and glycerol

(utooxidation- reaction o unsaturated lipid with oxygen.

malonaldehydes, peroxides

I. $B!9CC9

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The lo.er the / val,e the better

;tandard 'alues

resh ish J /1

9eKected value L /1

;hrimp L 2/1 reKected

. !hanges in !arbohydrates

(F9C*B!

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# M ()# (5#

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*acterial histidine decarboxylase-sensitive to temperature higher than 95

#otassium sorbate- inhibits growth o histamine-producing bacteria.

Methods o# Preserving 6Processing Fish

+.5emperature control - use o high7low temperature

. Hse o additives

I. Hse o packaging technologies

3. 9emoval o moisture -salting, drying7dehydration, smoking

2. Cther processing methodologies 4 marinating, ermentation, minced sh

processing

TEMPERAT!RE CO1TRO0

!se o# 0o. teperat,re

Chilling -aims to cool sh as quickly as possible to as low temperature as possible

without reezing

- the colder the sh, the greater the reduction in bacterial and enzymatic

action.

ICE -an ideal cooling media8 with very large cooling capacity

-harmless, comparatively cheap, can quickly cool

-occurs in diferent ormsE crushed, tube, aked, blocks

Properties o# Ice7

Bce requires a lot o heat to melt

6atent heat o usion 4 heat required to change a solid to a liquid

-+ kg o ice needs :/ kcal o heat to melt

Pilocalorie 4 amount o heat required to raise the temperature to +o

!

;pecic @eat 4 the capacity o the substance to hold heat when compared with

water.

;@E water Q+ wet sh Q /.0 rozen sh Q /.3

Bce Q /.2 air Q /.2 most metals Q /.+

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Hseul ormula to calculate the amount o heat to be removed to cool a substanceE

8 9 cT

"hereE R Q amount o heat to be removed %kcal7hr

m Q weight o the substance %kg&

c Q specic heat %kcal7kg-h-o!&

5 Q change in temperature %o!&

5o calculate how much ice is neededE

Ao,nt o# ice 9 860HF

Fx.+. !alculate the minimum amount o ice needed to

maintain +//kg sh in 2 o! temperature.

R Q mc5

R Q %+// kg& %/.0& %2o!&

Q 3//kcal7kg

(mount o ice Q R76@

Q 3// kcal7kg 7 :/kcal

Q I/ kg minimum ice need to cool sh

Other chilling edia7

+. !C6) (B9 4rerigerated or cold air is passed over sh in a chill room.

.;F(-"(5F9 B!F 4 adv. 6onger time to thaw8

disadv. Hneven chilling 7 reezing8

sh may absorb salt

- ofers more disadvantage than

reshwater ice.

I. 9F9B

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-superchilling media

-ofers advantages such as E rapid

cooling8 easier loading o sh8 sh are

not squashed or crushed8best or big

volume o sh catch

FREE:I12

change in the physical state o a substance rom a liquid to a solid, in which

energy or latent heat has to be removed rom the substance.

considered an excellent process or preserving the quality o sh or longer

period o time.

J-+/o!- most microbial activities stop.

EFFECTS OF FREE:I12

Bdeally, there should be no distinguishable changes between resh and rozen

products ater thawing.

*iological changes are very minimal.

( series o chemical, physical and histological changes occur in rozen sh

during excessively prolonged cold storage at temperatures below 4I/ o!

#artial and mild dehydration

Stages o# Free"ing

+. ;tage +- denoted by the all o temperature -removal o heat up to /o!. ;tage -conversion o water to ice8 crystallization o water.

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- critical zone or period o thermal arrest - at around -+o!I. ;tage I- urther cooling o rozen sh until it attains a

temperature o -I/o!

METHO4S OF FREE:I12

(ir blast reezer - blowing a continuous stream o cold air

over the sh.

!ontact or plate reezer 4 direct contact between sh and

a rerigerated surace.

Bmmersion in, or spraying with a rerigerated liquid

6iquid nitrogen %spray& reezer8 nitrogen gas %-2/o!&

-liquid nitrogen %-+0o!&

!arbon %inKection& reezer

6iquid rerigerant %spray-immersion& reezer 9+ %dichlorouromethane& %-

I/o!&

Bmmersion reezer 4 :21 saturated brine solution %-+

o

!&

H;F C @B

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. 5@F9$(6 #9C!F;;B=< 4 a process that involves the application o heat to

ood inside a hermetically sealed container

used to prevent ood spoilage and also ofers convenience due to long

shel-stability o canned oods

also known as appertisation to some 4 due to the inventor during civil

war bottled, canned, or tetrapacked %retortable pouches&

(!5C9; (F!5B=< 5@F9$(6 #9C!F;;B=< 9FRHB9F$F=5;

+. 9aw material quality - must always start with resh sh

. !ontainer size - larger containers have higher initial microbial loads.

- will determine processing time.

I. $ethod o heat transer

3. #roduct (cidity

PASTE!RI:ATIO14 a mild heat treatment given to oods that do not support the

growth o highly heat resistant microorganisms.

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STERI0I:ATIO14 a severe heat treatment given to oods capable o supporting

the growth o heat resistant microorganisms.

Absol,te Sterili"ation4 complete destruction o virtually all

microorganisms - not very good or ood processing8 destroys even

texture o ood.Coercial Sterili"ation4 aims to destroy the contaminating Clostridium

botulinumand other heat sensitive microorganisms!HT4 ultra high temperature 4 high temperature but short processing time

4ecial red,ction tie $4;val,e+4 the time required or the survivor curve to

traverse one logarithmic cycle at a specied temperature.

- the time needed to destroy 0/1 %+ log cycle& o the total microorganism.

- there is no such thing as +//1 destruction o microorganisms

e.g. )++.+ Q +./ min ---- + minute is required to reduce by 0/1 the

population o a bacteria

4;val,e ; an inde< o# heat resistance= species speci-c

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THERMA0 PROCESS SEVERIT>

F val,e-unit used or sterilization

-as dened, Sthe equivalent, in minutes at some reerence temperature, o

all heat considered with respect to its capacity to destroy spores or vegetative cells

o a particular organismT %;tumbo, +0NI& using this denition

o Q t Q ) %log =o 4 log =s&

measures the cumulative lethal efects o processing temperature and the time over

which the product is heated.

2illesp& Method- method used to calculate or the process severity o =C=-;!@F)H6F) #9C!F;;

Fquipment ailure

#ower loss

)rop o steam pressure

T&pes o# 1O1;SCHE4!0E4processes

5he process is more severe than specied.

5he process is less severe than specied.

Rec&cling- reers to the operations where heat sterilized produce is removed rom

cans and mixed with resh products at an earlier stage o production process.

Reprocessing- reers to the operation where processed product is subKected to a

second ull heat sterilization process.

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Fxtended processing- reers to the operation where the sterilizing process is

continued beyond the usual period o heating to achieve commercial sterility.

9eworking- reers to the operation where product is removed rom cans which

have not been subKected to any heat sterilization process and either lled into

new cans or mixed with another batch at an earlier stage in the productionprocess.

SPOI0A2E I1 CA11E4 PRO4!CTS $In 0o. Acid Foods+

lat sour 4 due to B.stereothermophilus8 can usually at with possible lost o

vacuum8 lowered p@ with souring odor.

5hermophilic anaerobe 4 due to C. saccharolyticum8 can swells then burst, has

ermented, butyric smell.

;ulphide stinker 4 due to C. nigrifcans, can can usually at8 has oul smell8 @;

production8 produce black spores

#utreactive anaerobes 4 due to C. sporogenes, C. botulinum;can swells then burst8

has product digestion with putrid odors and p@ increase

In Acid Foods

lat ;our 4 due to B. thermoacidulansand B. coagulans, can usually at8 little

vacuum change lower p@ with souring of odor

*utyric anaerobe 4 due to C. butyricumand C. pasteurianum8 can swells then burst8

has ermented, butyric smell

=on-spore ormers, mainly lactic acid bacteria 4 sot swells, with acid avor and

odor.

Aeast 4 can swells then burst8 has ermented yeasty odor

$oulds 4 at can with surace growth.

4EFECTS I1 THERMA00> PROCESSE4 PRO4!CTS

;poilage due to microbial causes

H&drogen s.ell4 can bulge due to production o hydrogen gas rom internal

corrosion8 caused by bumps in the can

Hard s.ell4 swell on both sides8 can could explode

So#t s.ell4 swell when pressed but goes back to original shape

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Springer4 when pressed on + side swell transer to the other.

Ph&sical de#ects4 %e.g. paneling, rust ormation& 4 could be generally due

to aulty retort operation, mishandling, etc.

C,rd #oration4 sot white to stif gray coagulated mass on the cut surace

o the meat.

Str,vite #oration4 odorless, generally harmless, tasteless crystals o

magnesium ammonium phosphate8 resemble glass ragments and are oten

mistaken as such.

Hone&cobing4 very common to tuna8 characterized by presence o pits in

the tissue8 happens when the raw material is no longer resh

Histaine #orationin canned tuna and tuna-like species.

OTHER FISH PROCESSI12 METHO4O0O2>

;(65B=