外文翻译--挑选的脱皮豆类混合大米压缩物的液流学与营养学的质量 英文版.pdf

ORIGINALARTICLERheologicalandnutritionalqualityofselecteddehulledlegumesblendedriceextrudatesS.Balasubramanian&AnjanBorah&K.K.Singh&R.T.PatilRevised:3November2010/Accepted:18December2010#AssociationofFoodScientists&Technologists(India)2011AbstractRheologicalandnutritionalqualityofready-to-eatrice(Oryzasativa)-legumeviz.blackgram(Vignamungo),greengram(Vignaradiata),lentil(Lensculinaris)andpeas(Pisumsativum)basedextrudateswerestudiedusinglowcostcolletextruder.Extrudateswerepreparedkeepingconstantfeedrate(25kg/h)andmoisturecontent(14%wb)at0,5,10and15%legumeincorporationlevels.RheologicalpropertiesofporridgemadeofextrudateflourwereevaluatedusingRapidViscoAnalyser(RVA).Maximumandminimumpeakviscosityforriceextrudatesaloneandriceextrudatesblendedwith15%peaswere697cpand523cp,respectively.Therewasadecreasingtrendindegreeofgelatinizationwithincreaseinlegumeincorpora-tionlevel.OtherRVArheologicalparametersliketroughbreakdownandfinalviscositywereintherangeof266-226cp,431-297cpand452-375cprespectively.Maximumvaluesofprotein,fat,fibreandashcontentswerefoundinriceextrudatesat15%legumesblendlevels.Therewasanincreasingtrendinnutrientcontentswithlegumecontentinriceextrudates.Degreeofgelatinizationforricealoneextrudatewas29.4%andshowedadecreaseingelatiniza-tionwithincreaseinlegumesextrudateandwasminimum(22.4%)forriceblendedwith15%dehulledgreengram.Sensoryevaluationscoresforallextrudatesshowedthemostacceptablerangeof6to8.Thus,legumeblendlevel(upto15%)ofdehulledlegumesfetchedgoodscoresandshowedpromisingtrendfortheproductionoflowcostexpandedextrudatesanditsinstantflour.KeywordsRice.Dehulledlegumes.Extrudates.Sensoryquality.NutritionIntroductionExtrusioncookingisoneoftheusefulprocessesfortheproductionofexpandedsnacksandinstantflours.Duringextrusioncooking,rawmaterialsundergohighshear,thusallowingpartialstarchhydrolysis(Colonnaetal.1984).Theexistingextrusionsystemsinvolvehigherfinancialinvestment,productioncapacityandtechnicalknowledgeandarenotsuitablefordevelopingcountries.Singlecolletextruders/dryextrudersthatweredevelopedforcomplementaryfoodsproductionduringearly1980sbytheUniversityofColorado(Harper1995,HarperandJansen1985,Said2000)aretoocostlybesideshighproductioncapacity(aboutRs2.5millionand1t/h).Adoptionofextrusioncookingprocessingforinstantflourproductionindevelopingcountrieshasnotstillpickedup.Thus,applicationofsimplemachinehavingsmallpro-ductioncapacityisthereforeofgreatpotentialinterest.Thepossibilitiesofalowcostcolletextruder(about2535kg/h)needtobestudiedfortheproductionofsnackfoodsandinstantflours.Rice(Oryzasativa),isoneofthemostfrequentlyusedcerealsformakinggluten-freefoodproducts(Sivaramakrishnanetal.2004).Legumesareaprimesourceofplantproteins,caloriesandothernutrients.Extrusioncookingoflegumesincreasesthedigestibilityoflegumeprotein.Inproductdevelopment,peakandfinalviscositiesareimportantparameters,tohaveanunderstandingofproductbehaviourduringandS.Balasubramanian(*):K.K.Singh:R.T.PatilCentralInstituteofPostHarvestEngineeringandTechnology,PAUCampus,Ludhiana141004Punjab,Indiae-mail:A.BorahTezpurUniversity,Tezpur784028Assam,IndiaJFoodSciTechnolDOI10.1007/s13197-010-0206-yafterprocessing.Rapidviscoanalysercanbeusedtoinvestigatethepastingeffectsoflipidsandaminoacidsonricestarchandflour(Liangetal.2002,LiangandKing2003).Thecompactstructureresultingfromextrusionprocesscanleadtoadenseproteinnetworkreducingtheavailabilityofstarchgranulestoattackbyalpha-amylase(Fardetetal.1999).Moreover,thephysicalbarriercreatedbytheproteinnetworklimitstheaccessibilityofstarchtoamylaseanddelaysinvitrostarchhydrolysis(Hoebleretal.1999).Variousreportssuggestedthatpastingcharacter-istics(Wiesenbornetal.1994,Lai2001),rheologicalpropertiesofpasteandgels(Wiesenbornetal.1994,Kimetal.1995)andotherfunctionalproperties(WottonandBamunuarachchi1978,Zobel1984)ofstarchesvarywithspeciesandvariants.Gelatinizationpropertiesofstarchesdependonthetype,granularstructure,botanicaloriginandamylose/amylopectinratio(Sajilataetal.2006).Waxyandnormalricegelatinizebetween60and78C(Thorburnetal.1987,Jenkinsetal.1994).Manyfactorsaffectpreferenceandacceptabilityoffoods.Somefactorsareintrinsictotheproduct,suchasappearance,tasteandflavour；otherfactorsareextrinsic,suchassocialandFig.2ParametersofthetypicalrapidviscoanalyzerviscosityprofileforlegumesblendedriceextrudatesFig.1LowcostcolletextruderJFoodSciTechnolculturalfactors(Delizaetal.1996).Keepingabovepointsinview,thepresentworkwasundertakentostudyrheologicalandnutritionalqualityofselecteddehulledlegumesblendedriceextrudates.MaterialsandmethodsDifferentdehulledlegumesviz.blackgram(Vignamungo),greengram(Vignaradiata),lentil(Lensculinaris)andpeas(Pisumsativum)andpolishedricewerepurchasedfromlocalmarket.Aftercleaningandgrading,therawmaterialswerecoarsegroundinplatemilltomakegritsintheparticlesizerangeof1.652.36mm.Differentlegumegritswereblendedat0,5,10and15%levelswithricegrits.Formakingextrudates,about2kgofblendedmaterialsconditionedto14%(wb)moisturewereused.LowcostcolletextruderItisasimplesinglescrewautogenousextruder,drivenbya7.5kWelectricmotor.Thebarrellengthis250mmwithalengthtodiameterratioof6:1andhasacentralcylindricaldieof4mmdiamand5mmlength.Therotatingspeedofthescrewishigh(500rpm)toallowhighshear.Thescrewconfigurationhasconstantpitchandflightdepthtoallowaprogressiveincreaseinfrictionforcesandtemperatureinsidethebarrel.Thescrewdiamis42.5mmandtherootdiamis32.5mm(Fig.1).Themoisturecontentwaskeptat14%.Theextruderbarrelwallhashelicalgroovestoenhancefrictionandcookingoftheproduct.Toensurearegularfeedingrate,theextruderisequippedwithamotorisedfeedingscrew,butitwaskeptconstant(25kg/h)forthisstudy.Afterextrusion,extrudateswereground(particlesize0.85mm)andsubjectedforrheologicalandnutritionalanalysis.RheologicalpropertiesPastingpropertiesofextrudatepowdersweredeterminedusingaRapidViscoAnalyser(RVA)Model3-D(NewportScientificPvt.Ltd,Australia)withThermoclinesoftware(3.0version)bytheMethodNo.162(ICC1995).Samplesuspensionwaspreparedbyplacingextrudatepowder(3g)inanaluminiumcanistercontaining(30g)distilledwater.Aprogrammedheatingandcoolingcyclewasused.Eachsamplewasstirred(960rpm,10s)whileheatedat50C,andthenconstantshearrate(160rpm)wasmaintainedfortherestoftheprocess.Temperaturewasheldat50Cupto1min.Thenthesampleswereheated(5095C,3min42s)andheldatTable1ParametersofviscosityprofileTraitsabbreviationDescription(referenceofterminology)PVPeakviscosity(61-02,BaoandXia1999)TTrough(61-02)BDBreakdown(BaoandXia1999,61-02),decreaseinviscosityduringcookingat95CFVFinalpasteviscosityattheendoffinalholdingperiodat50C61-02istheICC(1995)methods010020030040050060070080002004006008001000Time(sec)Viscosity,cpvGreengram010020030040050060070080002004006008001000Time(sec)Viscosity,cp010020030040050060070080002004006008001000Time(sec)Viscosity,cp0%5%10%15%Pea010020030040050060070080002004006008001000Time(sec)Viscosity,cpLentilFig.3TypicalrapidviscoanalyzerplotfordifferentdehulledblendedriceextrudatesJFoodSciTechnol95Cfor2min30s.Subsequentlysampleswerecooleddown(95-50C,3min48s)andthenheldat50Cfor2min.ARVAplotofviscosity(cP)versustime(s)wasusedtodeterminepeakviscosity(PV),trough(T),breakdownviscosity(BD)andfinalviscosity(FV)(Fig.2,Table1).Eachanalysiswasdoneinduplicate.NutritionalanalysisProteincontent(Kjeldahlmethod),fatandash(HartandFischer1971),andfibre(SadasivamandManickam1992)fordifferentlegumesblendedriceextrudatesweredetermined.DegreeofgelatinizationofextrudateswasdoneaccordingtoWoottonetal.(1971).SensoryevaluationAsemi-trainedpanelconsistingof11membersevaluatedtheextrudates.Thesensoryattributessuchascolor,flavour,surfacefinish,taste,crispinessandoverallacceptabilityofextrudateswereevaluatedusinga9-pointHedonicscale(14dislikeextremelytoslightly,5-neitherlikenordislike,69liketoslightlyextremely).Sampleswereservedtopanelistsimmediatelyaftercondi-tioningtheextrudates(105C,3min).StatisticalanalysisThedatareportedaremeanoftenobservationsandsubjectedtoMSEXCEL2000.ResultsanddiscussionEffectoflowcostcolletextruderonviscosityprofileofextrudatesAllviscosityparametersdetermineddecreasedwithincreasedlegumelevelsinblendascomparedtoriceextrudatesalone(Fig.3).Butthedecreasewasnotmuchpronouncedingreengrambasedextrudate.Thebreakdownviscositywasmaximuminpeaswhereasitvariedintherangeof288297cpandwaslowerinallthecases.Thefinalviscositydeclinedinallcasesbutthedecreasewasmuchhigheringreengramwhereitvariedfrom437to404cp.Similarobservationswererecordedforpeakviscosityalso.Whenextrudatespowdersuspensionswereheatedaboveacertaintemperature,waterpenetratedintothegranulesandweakenedthehydrogenbondsinstarchsegmentsandreflectedadegradativeRVAprofileascomparedtoitscorrespondin