Post Harvest Fisheries

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  • 7/26/2019 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


    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





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

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

    nicotinic acid&




    /.+ 4 21


    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&




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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


    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 the / val,e the better

    ;tandard 'alues

    resh ish J /1

    9eKected value L /1

    ;hrimp L 2/1 reKected

    . !hanges in !arbohydrates


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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



    !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


    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


    ;@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


    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.


    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!


    (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& %-


    Bmmersion reezer 4 :21 saturated brine solution %-+



    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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    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


    Aeast 4 can swells then burst8 has ermented yeasty odor

    $oulds 4 at can with surace growth.


    ;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.