Fish protein concentrate.ppt

Fish processing

1. Fish protein concentrate
Fishproteinconcentrateisanystablefishpreparation,intendedfor
humanconsumption,inwhichtheproteinismoreconcentratedthanin
theoriginalfish.
Theideaofafishproteinconcentrate(FPC)isthatastablefishmaterial
maybeproducedinwhichtheproteinismoreconcentratedthanin
originalfishandwhichisintendedforhumanconsumption.
Theideaofproducingafishproteinconcentrateisbynomeansnew.The
Norwegiansexhibitedbiscuitscontainingfishflourataninternational
exhibitionin1876.
However,itisonlyinthelasttwenty-fiveyearsthatextensiveendeavours
havebeenmadetoproducefishproteinconcentrate,andonlyinthelast
fewyearsthatmostofthetechnicalproblemsofmakingFPConalarge
scalehavebeensolved.
Theproductwasconsideredapanaceatofightprotein-malnutrition

2. What are the principal types of FPC?
The Food and Agriculture Organization of the United Nations defines three
types:
Type A Type B Type C
Protein (N X 6.25) (min) 67.5% 65% 60%
Moisture (max) 10% 10% 10%
Fat content (max) 0.75% 3% 10%
Chloride (max) 1.5% 1.5% 2%
Silica (max) 0.5% 0.5% 0.5%

3. Thefatcontentisimportantasitisthefatwhichtendstoproducestrong
flavours,particularlyifitisoxidized.
Tomakeastableproduct,notonlymoisturebutlipidcontentalsoshould
bereducedappropriately.Simplycookingandpressingofafishdonotgive
aproductwithsufficientlylowlipidcontent.
Odoursandtaste:TypeAshouldhavenomorethanafaintodourandtaste
whenwettedwithboilingwaterinaclosedcontainer
NospecificationscanbemadeforTypeBandCsincetheywillshowa
widerangeofodoursandflavours.
Bacteriology:Alltypesshouldbefreefrompathogenicanaerobes,
Enterococci,Salmonella/Shigella,Coagulase-positiveStaphylococciand
Clostridiaandhaveatotalbacterialplatecountat98.6
0
Fofnotmorethan
10,000pergram

4. Differentapproachestomakeastablefishproductmaybedivided
intothreemaingroups:
Microbiological methods: Ground fish is mixed with microorganisms
which in turn hydrolyse proteins to water soluble peptides, which are
separated from oil phase through centrifugation and dried
PrecipitationofsolubilizedproteinsthroughadjustmentofpH:
ProteinsarefirstsolubilizedbyadjustingpHofthedispersing
mediumtoalkalinesideandthenthesolubilizedproteinsare
precipitatedthroughthecontrolofpHtoalowervalueofabout5
Solventextractionmethods:Inasolventextractionmethod,ground
fishissubjectedtoextractionwithasolventwhichremovesboth
moistureandlipids.
Thesolventextractionmethodreceivedthewidestattention
Solventextractionandremovaloflipidsmaketheproductpractically
freeoffish–odoursandtheproductisexpectedtohaveuniversal
appealandmaybeincorporatedindifferenttraditionalandnon-
traditionalpreparations

5. Production of FPC type A
Unlesswhitefishareusedastherawmaterial,itispracticallyimpossible
toreduceoilcontentbelow1%withoutsomekindofextractionbysolvent.
Isopropylandethylalcoholsaretheextractantsmostcommonlyusedas
solventstoremovemuchofthefat,waterandfishytastingcomponents.
Typicaloftheprocesseswhichweredevelopedisthefollowingsequence
ofoperations.
Freshwholefisharerinsedwithfreshwatersoonafterlanding,weighed
andfedtoamincerbyaconveyor

6. Firstextraction:-Themincedfisharefedtoanextractorwhichisan
unheatedvesselinwhichtheminceisagitatedforabout50minuteswith
thesolventmixture.
Centrifugation:-Theslurryisseparatedintoasolidandaliquid.
Thesolidcakeisconveyedtothesecondextractorandtheliquidtoastill
forrecoveryofthesolvent.
Secondextraction:-Thecakeisagitatedwithsolventmixtureforabout
90minutesatatemperatureof75oc.
Centrifugation:-Theslurryisseparated.Thesolidissenttothethird
extractorandtheliquidtothefirstextractorforthenextbatchofraw
material.
Thirdextraction:-Thecakeisagitatedforafurther70minutesat750c
withfreshsolvent.Attheendofthisstagethefatcontentofthedrymatter
isreducedtoabout0.3%

7. Centrifugation:-Theslurryisagaincentrifugedandthewetcakewashed
withpuresolvent.Theliquidisusedinthesecondextractorforthenext
batch.
Solventremoval:-Thewetcakeisheatedinarotaryvacuumdryerto
evaporatethesolvent.Thevapoursaredrawnoff,condensedandused
again.
Grindingandpackaging:-Thedriedmaterialcanbeleftasaminceor
groundtoanydesiredparticlesize.
Thesolventandthesolidfishproteinmaterialmovethroughthe
extractorsinoppositedirections.
Thesolventbecomingmorecontaminatedwithwaterandfatasitmoves
fromthirdextractortothefirstextractor.
WhiletheFPClosesfatandwaterasitmovestheotherway.

8. Thefatcanberecoveredfromthesolventandsolventcanbeused
again.
Solventcostsarehighsothatefficientsolventrecoveryisvery
important
Theextractedfatisnormallymuchdarkerthanthatextractedby
pressingbecausesolventextractionremovesmoreofthefatincluding
oxidizedproductsandphospholipids.
Themarketvalueofthisfatislikelytobelowerthanthatofnormaly
producedfishoil.

9. FPC type B production
SincetypeBFPChasnorestrictionsastoitsodourandflavourany
processwhichproducesastableproteinconcentratecanbeconsidered
andsolventextractionsisnotnecessarybecauseofthehigheroil
content.
Itcanbeproducedfromanykindoffishanditsmanufacturingprocessis
muchlesscomplexandlessexpensive.
FPCtypeBandCisessentiallyanon-defattedandnon-deodorised
cookedhotairdriedfishmince.Itisalsodescribedasfishflourforuse
asfood,asdistinctfromfishmealwhichisusedasanimalfeed

10. Production of FPC by enzyme hydrolysis
AnenzymiticallyproducedFPCthatisblandinflavourandhasgood
functionalpropertieshasbeenproducedusingpapain,pancreatin,
bromelinorficin.
Theprocessconsistsofhydrolyzingthefishproteinandcomplexingit
withphosphate.
Theprotein-phosphatecomplexisprecipitatedatapHof2.5to3.5and
theprecipitateiscentrifuged,washedandextractedwithapolar
solventtoremoveitfromthelipids.
Theprecipitatedcomplexisneutralizedwithabaseand10-20%
carbohydratesareadded.Itisthendriedbysprayorfreezedrying.

11. FunctionalpropertiesofFPC
Theterm“functionalproperties”isusedtodescribethosephysicaland
chemicalcharacteristicsofafoodwhichcontributetotheirperformance
duringmanufacture,processing,storageandconsumptionexceptits
nutritionalones.
Attributessuchascolour,flavour,solubility,mettability,foaming
behaviour,andinertnessaswellasrheologicalpropertiesofthesolution
andgelsformaprofileofpropertieswhichcontributetotheacceptanceof
theproduct.
ThefailureofFPCtobeacceptedasafoodadditiveisattributedpartly
duetoitspoorfunctionalproperties.
UnmodifiedFPChasanextremelylowwateraffinityandimpartsagritty,
powderytexturetofoods

12. AttemptsweremadetoimprovethefunctionalityofFPCbyavarietyof
methodsincludinggentleprocessingconditionsandhydrolytic
modificationbychemicalandenzymicprocess.
Alkalitreatmentshowimprovedmelting,swellingandfoaming
properties.Theuseofenzymes(trypsin,bacterialproteases)gives
excessivehydrolysis,leadingtoincreasedsolubilitybutno
improvementinfunctionalproperties.
InthemanufactureofFPCtypeB,concentratedfishsolublesareadded
backtothepresscakebeforeenteringthedrier.
Theaddedsalts,aminoacidsandothersolutesaddedbacktothe
presscakelowerthewateractivityoftheproduct.
FPCisnotintendedtobeusedasacompletediet,rather,itsuseasa
highqualityproteinsupplement.

13. Ithasanexcellentaminoacidbalanceandisparticularlyeffectiveasa
supplementtocereals,whicharelowinlysine.
Residual‘fishy’flavourlevelsanditspoorfunctionalitieslimitits
proportioninfoodstoaround10%dependingontheavalityofthe
product.
ThehopethatFPCwouldbethesolutiontothenutritionalproblemsof
theworldhaslargelydisappearedwiththelackofacceptanceandthe
failureofmostofthecommercialscaleventures.
Recentresearchhasbeentowardsimprovingthefunctionalproperties
offishproteinconcentrateswiththeaimofovercomingtheacceptance
difficulty.

14. How does FPC differ from fish meal?
Fishmealasproducedthroughouttheworldisaverycheappotential
FPC,butitisnotintendedforhumanconsumption;itisusedfor
makingpigandpoultryfeedsforfarming.Ordinaryfishmealis
unsuitableforhumanconsumptionforthreemainreasons:
1.Itisnotnormallymadeundersufficientlyhygienicconditionstorule
outtheriskofoccasionalcontaminationbydisease-causing
bacteria.
2.Itusuallycontainsrancidfatwhichdestroyscertainvitaminsand
maylowerthenutritivevalueoftheprotein;afishmealdietmight
precipitatevitamindeficiencyinpoorlynourishedpeople.Moreover
theflavouroftherancidfatisunacceptableinmanysocieties,
thoughnotinall.
3.Thereisaslightriskthattherancidfatmayhaveacumulativetoxic
effectifconsumedoveralongperiod.
Thefirstofthesereasonsisthemostimportant;thusfishmealmade
underhygienicconditionsiscalledFPCtypeC.