viz THE CFC/ICCO/INIAP COCOA PROJECT “TO ?· CHEMICAL AND ORGANOLEPTIC PARAMETERS TO DIFFERENTIATE…

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    THECFC/ICCO/INIAPCOCOAPROJECTTOESTABLISHTHEPHYSICAL,CHEMICALANDORGANOLEPTICPARAMETERSTODIFFERENTIATEBETWEENFINEANDBULKCOCOA SOMEHIGHLIGHTSFROMTHE

    ORGANOLEPTICCOMPONENT

    D.A.Sukha1,D.R.Butler 1,F.Amores2,J .C.J imnez2,G.Ramos3, A.Gomez3,A.Zambrano3,N.Hollywood4andJ .Ravushiro5

    1CocoaResearchUnit,UniversityoftheWestIndies,TrinidadandTobago.2InstitutoNacionalAutonomodeInvestigacionesAgropecuarias(INIAP),Ecuador.3InstitutoNacionaldeInvestigacionesAgrcolas(INIA),Venezuela.4QueenslandDepartmentofPrimaryIndustries(QDPI),Australia.5CocoaCoconutInstitute(CCI),PapuaNewGuinea.

    SUMMARY

    TheprojectToestablishthephysical,chemicalandorganolepticparameterstodifferentiatebetweenfineand bulk cocoa (referred to as the CFC/ICCO/INIAP Cocoa Flavour Project) was funded by theCommon Fund for Commodities (CFC) and other cofinanciers, sponsored by the ICCO and executedthrough INIAP, Ecuador. The project started in 2001 with participants from four fine or flavourproducingcountriesviz.Ecuador,PapuaNewGuinea (PNG),TrinidadandTobagoandVenezuela. Thecentralobjectiveofthisprojectwastodevelopuniversallyacceptedcriteriatodifferentiatebetweenfineorflavourandbulkcocoasthroughaseriesofscientificevaluationsofphysical,chemicalandorganolepticparameters.Theprojectalsoaimedtoprovidemethodologiestoenabletheevaluationofcocoaqualityinrelationtogenotypeandtheenvironment,aswellastoprovideanddisseminatemethodologies,standardsandinstrumentstobeusedintheevaluationofcocoaquality.Thispaperhighlightssomefindingsfromtheorganoleptic component of the project. We have been able to document via systematic study clearorganoleptic differences between fine or flavour and bulk cocoas. Additionally, we have demonstratedgenotypicdifferencesintheancillaryflavourscharacteristicoffineorflavourcocoasandfoundarangeofflavoursthatvarygreatlyamongcountriesgrowingfineorflavourcocoa. Finallywehaveobservedastrong impact of growing environment on the flavour of genetically identical clones grown in differentcountries.

    Keywords:CFC/ICCO/INIAPCocoaFlavourProject,growingenvironment,methodologies,standards,darkchocolates,ancillaryflavours

    INTRODUCTION

    In1998theInternationalCocoaOrganisation(ICCO)forwardedaprojectproposalwithits recommendation for financing through theCommon Fund for Commodities (CFC).Thiswas a Project to establish the physical, chemical and organoleptic parameters todifferentiatebetweenfineandbulkcocoa(referredtoastheCFC/ICCO/INIAPCocoaFlavour Project) sponsored by the ICCO and executed through Instituto NacionalAutonomo de Investigaciones Agropecuarias (INIAP), Ecuador. The project wasinitiated in 2001with participants from four fine or flavour producing countries viz.Ecuador,PapuaNewGuinea(PNG),TrinidadandTobagoandVenezuela.

    The central objective of the CFC/ICCO/INIAP Cocoa Flavour Project was to developuniversally accepted criteria to differentiate between fine or flavour and bulk cocoasthroughaseriesofscientificevaluationsofphysical,chemicalandorganolepticparameters.

    The research conducted in this project was completed in 2005 and a selection oforganolepticandotherresultscanbefoundinSukha,Bharath,StrakerandButler,(2003,

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    2004)andSukha,RamnathandButler,(2005).Thisarticlewill presentsomehighlightsofresultsfromtwoexperimentsconductedwithintheorganolepticcomponentoftheproject.

    The first experiment compared flavour profiles from cocoa samples produced by eachproject member country with a sample from Ghana. The second experiment was toexamine flavour profiles of the same cocoa clones grown and processed in differentcountries(commonclones).

    MATERIALSANDMETHODS

    SampleverificationThe identities of all trees in Trinidad used in this project were verified by assessingmorphologicalcharactersand bymolecularanalysis (SimpleSequenceRepeats (SSR)).VerificationofthecommonclonesbetweenTrinidadandVenezuelawasdoneusingpodphotographs andmolecular analysis of leaf samples carriedout at theCocoaResearchUnit (CRU), (Trinidad). Othermolecular verificationof samples fromallparticipatingcountrieswasdoneatPlantResearchInternational,(TheNetherlands)andUnitedStatesDepartmentofAgriculture,(USA)usingcapillarysequencers.

    SamplepreparationAdetailedaccountof theprotocol followedfor samplepreparationviz. fermentationanddrying(primaryprocessing)androastingandmilling(secondaryprocessing)aswellastheorganoleptic assessment procedure can be found in the proceedings of theworkshop toestablish working procedures for the CFC/ICCO/INIAP Cocoa Flavour Project (Sukha,2001a, 2001b) and in the organoleptic results section (Sukha and Butler, 2006) of theproceedingsofthefinalworkshopfortheCFC/ICCO/INIAPFlavour.Thefollowingisasummaryofthesamplepreparationandassessmentprocedure.

    FermentationanddryingThe majority of samples were processed as microfermentations in labelled nylon netbagsweredoneusingbeansfromfullymature,undamagedandhealthypods.InTrinidadthebagswereinserted30cmfromthetopofasweatboxcontainingapproximately2000kgofwetcocoaand inEcuador,PNRandVenezuelaasmallersweatboxwitha200250kgwetbeanweightcapacitywasused.ThefermentationtimesandturningregimesforeachcountryaregiveninTable1.

    Table1. Fermentation timesand turning regimesadopted ineachcountry for theCFC/ICCO/INIAPFlavourProject.

    CountryLocalclones Commonclones

    Fermentationtime(h)

    Turningfr equency(h)

    Fermentationtime(h)

    Turningfr equency(h)

    Ecuador 96 144 48(onceonly) 168 48(onceonly)PNG 168 192 24(daily) 168 24(daily)Trinidad 168 48(twice) 168 48(twice)Venezuela 24 48 24(onceonly) 168 48(twice)

    Fermentedsamplesweresundriedinallcountries,normallyfor120hours,anddryingwascompletedinanovenifnecessarytoreachafinalmoisturecontentof6 7%.

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    SecondaryprocessingSubsamples of 300 330 g of dry beanswere taken from a coned and quartered beansample. Thesewereroasted inamechanicalconvectionovenat temperaturesandtimesthatdifferedineachprojectmembercountryaccordingtotheir localclones. InEcuador,local clones were roasted at 130C 30 minutes and common clones at 145C 30minutes. InPNGandTrinidadallbeanswereroastedat145C30minutesand140C30minutes,respectively. InVenezuela,localcloneswereroastedat110C25minutesandcommonclonesat145C30minutes.

    Liquors were prepared with amortar and pestle mill in Trinidad and PNG, andwith ablander in Ecuador and Venezuela. After milling or blending, the cocoa liquor wastransferredto120mLcapacitysterilespecimencontainersthatwerestoredat8to20Cpriortoorganolepticevaluations.

    OrganolepticevaluationAfter completing an initial prescreening questionnaire, panellists were screened usingbasictastesidentificationandtastesensitivityviathresholdconcentrationtests.Panellistsselectedfortrainingwereintroduced tococoaflavourattributesandvocabularygeneration.They were trained in identifying cocoa offflavours, aswell as, scoring and ranking offlavourattributesbypairedcomparisontestsandfinallyprofilingwithpanellistcalibrationandhiddenreferences.

    Liquorswerethenassessedbyatrainedpanelofat leastsixpersons inasensorydesignthat incorporated hidden reference liquors to check panellist consistency betweenrepetitions. Randomlyselectedthreedigit codeswereassigned tococoa liquorsandtheorder of tasting liquors was randomised over three repetitions to minimise carryovereffects. No two panellists received liquors in the same order in any given evaluationsession.Sensoryprofileswererecordedfornineflavourattributesusing10cmlinescaleswithapossiblerangeofscoresfrom0to10,thehighernumbersdenotedstrongerflavourintensities.

    GhanareferenceAhomogenousbatchoffermentedanddriedbeansfromGhanawassetasideforuseinthisprojectoverthethreecropyearsbyGuittardChocolateCompany.Subsamplesfromthisbatchofbeansweresenttoeachprojectmembercountryatthestartoftheproject.GhanaistheindustrystandardforbulkcocoaandwherepossiblebeansfromthisGhanasamplewereusedasa bulk referencefororganolepticassessments.

    CommonclonesCocoaliquorsofcommonclonesgrowninPNG,EcuadorandVenezuela,eachprocessedintheirrespectivecountryoforigin,weresenttoTrinidadforevaluationbythetastepanelatCRU. Thisalloweddirectcomparisonby thesamesensorypanelof thesameclonesgrownandprocessedindifferentcountries.Itwasnotpossibletohavethesamecommonclonespresentinallprojectmembercountries,howeverthewiderangeofgenotypesgrownintheInternationalCocoaGenebank,Trinidad(ICG,T)madeitpossibleforevery commonclonetobecomparedwiththesamecloneinTrinidad.

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    DataanalysisIndividual flavour attribute scores from the profiling forms were entered into a datatemplateinMicrosoftExcel.Meanflavourprofilesandthestandarderrorsofthemeanwere calculated. Variance components were investigated using restricted maximumlikelihood (REML) variance estimation with Genstat 4.24 DE (VSN International) todetermine the significance of treatment effects and interactions. Principal componentanalysis(PCA)was performedonthepooleddatausingPalaeontologicalstatisticssoftware(PAST)Version1.34(Hammer etal.,2001)andgraphicalrepresentationwascarriedoutinMicrosoftExcel and PAST.

    RESULTS

    TrinidadREMLvarianceestimatesshowedsignificantdifferencesbetweentheCCLlocalclonesfromTrinidad and theGhana reference forall attributesexceptastringencyand otherflavours.Differences in cocoa, acid, fruity, floral and nuttywere all highly significant(P0.001).Typically the samples fromTrinidadwere characterised by dominant fruityflavours with some samples being either predominantly floral, such as Trinidad localcloneCCL200,orhavingamixtureof fruityand floral. CCLclonesweremoderatelyacidbutaveragescoresnevercrossedanintensityof4onthe0to10scale. Lowstandarderrors(

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    Cocoa

    Acidity

    Astringency

    Bitterness

    Fruity

    Floral

    Nutty

    Raw/beany/green

    Caramel/Malt/Other

    CCL202CCL217

    CCL201

    CCL200

    Ghana(TnT)

    KA2106KA7314/1

    Ghana(PNG)

    CCAT2664CCAT4688

    LaGloria

    Gha