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Amino

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Aminoamino,Amino

    Amino

ChineseJournalofChemicalEngineering,16(3)456460(2008)

    ;AminoAcidsProductionfromFishProteinsHydrolysisin ;SubcriticalWater

    ;ZHUXian(朱宪),ZHUChao(朱超),ZHAOLiang(赵亮)andCHENGHongbin(程洪

    )

    ;DepartmentofChemicalEngineering,SchoolofEnvironmentandChemicalEngineering,

    ShanghaiUniversity,

    ;Shanghai201800,China

    ;1INTRoDUCTIoN

    ;Chinaisthelargestmarketoffisheryintheworld. ;andthereisapproximately40%oceanmarineproducts ;processedinChina1],butthefishproteinsutilization ;ratioisless30%.Besides.40%45%wastescanbe

    ;producedinfisheryprocessing.whichmeansthatalarge ;amountofbiomassisdiscardedaswaste.Thesewastes ;alsocontainalotofproteinsandbioactivematter2].

    ;Thechemicalpropertiesofsuper(sub)critical ;wateraresimilarwithacetone,anditsionicproductis ;overthousandfoldthatofnormalwater.So,itplays ;theroleofcatalystasacidoralkaliwithoutanyenvi

    ;ronmentalpollution[3-7].ThebiomasscanbehVdro

    ;lyzedintohighvalueindustrialrawmaterial:amino ;acid,unsaturatedfattyacid(DHA,EPA,etc.),oil, ;polysaccharideandsoon.YoshidaP,.[8]studied ;hydrolysisoffishforproducingaminoacidsbyusing ;asetofstainlesssteeltubewith5mlcapacityunder ;protectionofargon.Inthisarticle,weinvestigated ;hydrolysisoffishproteinsinasuper(sub)criticalwater ;reactorwith400mlcapacitytoproduceaminoacid. ;Theselaydrolysisexperimentswerestudiedunderthe ;atmosphereofair,nitrogenorcarbondioxideinstead ;ofargontoreducethecostofindustrialproduction. ;Undertheconditionofwaterexcess.themacroscopic ;reactionkineticswereobtainedforfishproteinshydroly

    ;sis.Theseresultsareveryusefulforindustrialization. ;2EXPERIMENTAL

    ;2.1Materials

    ;(1)Fishmeat:purchasedfrommarket

    ;f2118kindsofpureaminoacidreagent(bio

    ;chemicalreagentgrade):ShanghaiKangdaAmino ;AcidFactory.

    ;(31Hydrochloricacid36%(bymass)ARgrade. ;(4)AAADirectaminoacidanalysisapparatus: ;D10NEXCo..USA.

    F(0.2L+1.5MG)/30MPaIIAsuper-critical ;(51HL

    ;waterequipment:HangzhouHualiPumpCo.(Fig.1); ;reactiontemperaturefromroomtemperatureto550.C: ;reactionpressure.035MPa;capacity.2001300m1.

    ;(61ElectronicscaleAB104N:MettlerToledoCo., ;Shanghai.

    ;2.2Subcriticalwaterhydrolysis

    ;TheexperimentalflowchartisdepictedinFig.1. ;Thereactorwasfilledbychosenreactionatmosphere ;(nitrogen.airorcarbondioxide1at0.15MPa.Then ;putquantitativedeionizedwater(about200m1)into ;reactorandsetreactiontemperatureforthermostat. ;Thefishmeatemulsionwaspreparedwithacolloidal ;milltogetthehomogeneousmilkysampleatthecon

    ;centrationof100gmeatperliter~Whenthetempera

    ;tureandpressureofreactorreachedtothepresetval

    ;ues,fishproteinsemulsionsamplewasinjectedinto ;reactorbyhighpressuremeteringpumprapidly.Al

    ;thoughnostirringwasapplied,themixturewasin ;boilinglikestatusunderthesubcriticalstate.The ;timerstartedafterinjection,andsamplingwascon

    ;ductedatregularintervalforanalysis.

    ;2.3Hydrochloricacidhydrolysis

    ;Thefishproteinshydrolysiswascarriedat108.C ;Received20070925.accepted20080301.

    ;SupposedbytheNationalNaturalScienceFoundationofChina(50578091)andShanghai

    LeadingAcademicDisciplineProject

    ;(T-105).

    ;Towhomco~espondenceshouldbeaddressed.Email:xzhu@staff.shu.edu.ca ;

    ;Chin.J.Chem.Eng.,Vo1.16,No.3,June2008 ;Figure1F1OWchartofsubcriticalwaterhydrolysisexperimentalapparatus

    ;1feedingvesse1;3_reacti0natmospherebottle;4,5ump;6,7

    watertank;8~pressurereactor;9--feedingfunnel; ;10---samplingdevice;11--coolingdevice;12--collector ;300

    ;200

    ;

    ;100

;05.010.015.020.025.030.035.040.0

    ;Figure2Compareofaminoacidchromatogrambetweenstandardandsamplehydrolysateo

    ffishproteins

    ;a--arginine;blvsine;calanine;dtnreonine;eglycine;tVaJ1ne;proline;n

    senne;l--lsoleuclne;j--leuclne;

    ;k_

    methionine;1_histidine;m~phenylalanine;n--glutamicacid;o--aspartate;p--cystme;q

    tyrosine;r~tryptophan

    ;for28hin20%(bymass)HC1solution.Thetotal ;aminoacidyieldinhydrolysatewastakenasthetheo

    ;reticaltotalaminoacidsyieldafterentirelyhydrolyzed. ;2.4Aminoacidanalysis

    ;Thequantitativedeterminationoftheaminoacids ;wasdeterminedbyBioLC(AminoAcidAnalyzer, ;D10NEX.USA,.Comparisonofaminoacidchroma

    ;togrambetween18kindsofaminoacidstandardsam

    ;piesandhydrolysatesampleoffishproteinswas ;showninFig.2.

    ;3RESUISANDDISCUSSION

    ;3.1Reactiontemperature

    ;Figure3showsthattherelationshipofaminoacid ;yieldwithreactiontemperatureisdifferentfordifferent ;kindsofaminoacidunderthesamereactiontimeand ;pressure.Theyieldofaminoacidinhydrolysaterises ;withincreasingtemperatureatfirst,thendecreases, ;exceptcystinewhoseyieldseemsverylowandinde

    ;D

    ;bD

    ;g

    ;

    ;temperature/.C

    ;Figure3Effectofreactiontemperatureonaminoacid ;yield(5MPa,30min)

    ;tyrosine;arginine;?alanine;?cystine;-isoleucine;

    ;?leucine;?histidine;phenylalanine

    ;pendentwithtemperature.Thisisperhapsbecauseof ;decompositionofaminoacidin115lghtemperature9].

    ;Thereisamaximumyieldforeachaminoacid,butthe ;correspondingtemperatureisdifferentfromeachother. ;3.2Reactiontime

    ;Figure4showsthattheyieldofaminoacidsin ;

    ;Chin.J.Chem.Eng.,Vo1.16,No.3,June2008 ;

;?

    ;

    ;

    ;reactiontime/rain

    ;Figure4Effectofreactiontimeonaminoacidyieldin ;hydrolysate(5MPa,260.C)

    alanine;?cystine;?isoleucine; ;tyroine;arginine;?

    ;?leucine;?histidine;vphenylalanine

    ;hydrolysateriseswithincreasingreactiontimeatfirst, ;thendecreasesalittle,exceptcystinewhichislike ;independentwithreactiontime.

    ;3.3Reactionpressure

    ;7

    ;6

    ;5

    ;?

    ;4

    ;3

    ;>,2

    ;1

    ;pressure/MPa

    ;Figure5Effectofpressureonaminoacidyieldinhydro. ;lysate(260.C,30min)

    ;tyrosine;arginine;?alanine;?cystine;?isoleucine

    ;?leucine;?histidine;vphenylalanine

    ;tyrosineandphenylalaninemaybeinair.

    ;Itisfoundthataminoacidscouldbeproducedin ;air,nitrogenorcarbondioxide,anditismuchcheaper ;thanothermethodsofhydrolysisforbreakingdown ;biomasSwn1chrequtreexpensiveargongas.111ISlm

    ;provementcanhelpinindustrialconversionot1310

    ;massintoausefulresource.

    ;Figure5showsthattheeffectofpressureon ;yieldofaminoacidsinhydrolysat

    ;.

    ;esnotverymarked4HYDROLYSISKINETICS

    ;ascomparedw1thtemperatureandlame.

    ;3.4Contrastofdifferentatmosphereresults ;Figure6showsthattheeffectofdifferentreac

    ;tionatmosphereondifferentaminoacidyieldinhy

    ;drolysateisdifferent.NOmatterwhateveratmosphere ;isused,thereisagiventemperatureformaximum ;yieldofaminoacidinhydrolysate.Fig.6suggestthat ;leucine.histidineandisoleucineshouldbehvdrolyzed

    ;inatmosphereofnitrogenorcarbondioxide,while ;

    ;?

    ;h

    ;

    ;,

    ;>,

    ;temperature/.C

    ;(a)Leucine

    ;

    ;

    ;

    ;?

    ;g

    ;

    ;Biomasshydrolysiskineticsinsuper ;fsub)criticalwaterhavebeenstudied[1012].Hy

    criticalwater ;drolysiskineticsoffishproteinsinsub

    ;wasresearchedinthisarticle.

    ;4.1Kineticsformulaoffishproteinshydrolysis ;Itisverydifficulttoanalyzethefishprotein,but ;veryeasytodeterminethetotalyieldofaminoacids ;temperature/.C

    ;(b)Tyrosine

    ;

    ;

    ;

    ;?

    ;bo

    ;

    ;temperature/~C

    ;(c)Histidine

    ;temperature/.Ctemperature/.C

    ;(d)Isoleucine(e)Phenylalanine

    ;Figure6Theaminoacidyieldinhydrolysateoffishproteinsversustemperatureundernitrog

    en(?),air(?),carbondioxide

    ;(?)atmosphererespectively

    ;

    ;Chin.J.Chem.Eng.,Vo1.16,No.3,June2008459 ;inhydrolysateatdifferentreactiontimebyusing ;AAADirect.TheaminoacidyieldrateXatanytime ;canbedefinedas:

    ;X=M(a)f/M(a)0

    ;whereM(a1isthetotalamountofaminoacidsinhy

    ;drolysateatdifferentreactiontime.M(a)othetotal ;amountofaminoacidsinhydro1Vsateoffishproteins ;entirehydrolysisbyusinghydrochloricacid.So,the ;fractionofremainderfishproteinsatanytimeis1X.

    ;Thehydrolysisoffishproteinsisasfollows:

    aminoacid+otherproducts ;fishproteins+water

    ;(2)

    ;So,thehydrolysiskineticequationmaybeexpressedas ;d(1x)/dt=-K(1X)”[H20](3)

    ;inwhichtisthereactiontime(),Kthehydrolysis