05-castro_05b-tomazic 30/12/13 20:28 Page311 STUDY OF PHENOLIC POTENTIAL OF SEASONED AND TOASTED PORTUGUESE WOOD SPECIES (QUERCUS PYRENAICA AND CASTANEA SATIVA ) LucíaCASTRO-VÁZQUEZ 1,MariaElenaALAÑÓN 2* ,JorgeManuelRICARDO-DA-SILVA 3, M.SoledadPÉREZ-COELLO 4 andOlgaLAUREANO 3 1:FoodTechnologyArea,FacultyofPharmacy,UniversityofCastilla-LaMancha, CampusUniversitario,Albacete,Spain 2: HughSinclairHumanNutritionGroup,DepartmentofFoodandNutritionalSciences,SchoolofChemistry, FoodandPharmacy,UniversityofReading,WhiteknightsRG66AP,Reading, UnitedKingdom 3: UniversidadeTecnicadeLisboa,InstitutoSuperiordeAgronomia,LaboratorioFerreiraLapa (SectordeEnologia),1349-017Lisboa,Portugal 4:FoodTechnologyArea,FacultyofChemistry,UniversityofCastilla-LaMancha,CampusUniversitario, CiudadReal,Spain Abstract Résumé Aim :Thephenolicpotentialandsuitabilityofseasonedand Objectif :Lepotentielphénoliqueetl’aptitudedesboisde toasted Portuguese chestnut( Castanea sativa Mill)andoak châtaignier( Castanea sativa Mill)etdechêne( Quercus wood( Quercus pyrenaica )asalternativecooperage pyrenaica )portugaisséchésetchaufféscommealternative materialswereevaluated. auboisdetonnellerietraditionnelleontétéévalués. Methods and results :Low-molecular-weightphenolsand Méthodes et résultats :Lesphénolsdefaiblepoids ellagitanninsfromseasonedandtoastedPortuguesewood moléculaireetlesellagitaninsontétéanalysésdanslesdeux specieswereanalysedbyHPLC. C. sativa wasfoundtobe espècesdeboisportugais.Leséchantillonsde C. sativa richerinphenoliccompoundsthan Q. pyrenaica .High étaientplusrichesencomposésphénoliquesqueles concentrationsofvescalaginandgallicacidwerespecificto échantillonsde Q. pyrenaica .Lesconcentrationsélevéesde C. sativa . Toastingsignificantlyreducedtheellagitannin vescalaginetd’acidegalliqueétaientcaractéristiquesde contentinbothwoodtypes,albeitlessmarkedlyin C. l’espèce C. sativa .Letoastageaentrainéunediminution sativa .Asregardsphenolicaldehydes, C. sativa contained considérabledelateneurenellagitaninsdanslesdeuxtypes substantiallygreateramountsofvanillicaldehyde,anodour- debois.Cependant,cettediminutionétaitmoinsprononcée activecompound,than Q. pyrenaica . dansleséchantillonsde C. sativa quedansceuxde Q. pyrenaica .Encequiconcernelesaldéhydes Conclusion :BothtypesofPortuguesewoodaresuitablefor phénoliques, C. sativa présentaitdesquantitésbeaucoup useascooperagematerials,althoughchestnutwoodisbetter plusimportantesd’aldéhydevanillique,uncomposé suitedtotheheattreatmentinvolvedinthecoopering odorant,comparéauxéchantillonsde Q. pyrenaica . process. Conclusion :Lesdeuxtypesdeboisportugaispeuventêtre Significance and impact of the study :Portuguesewood utilisésentonnellerie.Cependantleboisdechâtaignierest speciesprovideaneffectivealternativetotheoakwood plusadaptéàlachauffe. speciestraditionallyused foragingalcoholicbeverages . Signification et impact de l’étude :Lesespècesportugaises Key words :cooperagewood,Portuguesespecies,phenolic deboisoffrentunebonnealternativeàl’utilisationdebois composition,toastingeffect dechênetraditionnellementutiliséspourlevieillissement desboissonsalcoolisées. Mots clés :boisdetonnellerie,espècesportugaises, compositionphénolique,toastage manuscript received 17 October 2012 - revised manuscript received 29th July 2013 J. Int. Sci. Vigne Vin , 2013, 47 , n°4, 311-319 *Correspondingauthor : [email protected] - 311 - ©Vigne et Vin Publications Internationales (Bordeaux, France) 05-castro_05b-tomazic 30/12/13 20:28 Page312 L.CASTRO-VÁZQUEZ et al. INTRODUCTION Portuguesewoodhasrecentlybeenconsideredforuse inbeverageagingprocesses.Thus,Portuguese Theuseofwoodenbarrelsisatraditional,common chestnutwoodhasbeenusedtoagebrandies(Canas et practiceforagingwinesandotherbeveragesbyvirtue al. ,1999).However,thechemicalcompositionof ofthefavourableeffectsofwoodonagedproducts. thesePortuguesespecies( C. sativa and Q. pyrenaica ) Contactwiththebarrelaltersthecompositionof hasscarcelybeenstudied,particularlyasregards beveragesthroughthereleaseofvariousvolatile phenolicprofile. compoundsandpolyphenols.Thus,tannins,phenolic acids,andfreeandglycosidicellagitannins( β-1- O- Inthiswork,thechemicalcompositionofPortuguese ethylvescalagin,flavano-ellagitannins,and C. sativa and Q. pyrenaica specimenswasstudied. anthocyano-ellagitannins)playacentralrole Thispreliminaryanalysisfocusedonthepolyphenol intheastringency,bitterness,roundnessandcolourof fraction ,whichis oneofthemostimportantfactors winesanddistilledspiritsagedinwoodbarrels governingthesuitabilityofwoodforcooperageby virtueofitsinfluenceoncolourstability,co- (Chassaing et al. ,2010 ;Saucier et al. ,2006 ;Jourdes pigmentation,protectionfromoxidation,and et al. ,2011). astringencyinagedwines(BrouillardandDangles, Oakwoodisbyfarthemostwidelyusedforthis 1994 ;Cejudo-Bastante et al. ,2011 ;Darias-Martin et purpose.Traditionally,threeoakspecieshavebeen al. ,2001 ;Del-AlamoandNevares,2006 ;Jordão et extensivelyusedforbarrelproduction :namely, al. ,2007 ;Monedero et al. ,2000 ;Roureand Quercus alba L., Quercus petraea (Matt.)Liebl.and Anderson,2006 ;VivasandGlories,1996 ; Quideau et Quercus robur L.Americanforestsarethemain al. ,2005 ). sourcesoftheformerspeciesandFrenchforeststhose Toasting,whichiscommonlyusedincooperageto ofthelattertwo.Indeed,winemakerstypicallyreferto improvethesensorypropertiesofagedwines,hasa thewoodtypescommonlyusedtoagewineas stronginfluenceonthepolyphenoliccompositionof AmericanoakorFrenchoak.Theirwidespreaduse wood ;also,asrevealedbyrecenthumansensory hasfosteredstudiesontheinfluenceofgeographical experiments,itdecreaseswoodastringencyby location(Americanvs.Frenchforests)onthe convertingvescalaginandcastalagininto less chemicalcompositionofoakwood(Chatonnetand astringentdegradationproducts(Glabasniaand Dubourdieu,1998 ;Doussot et al. ,2002 ;Nishimura Hofmann,2007). andMatsuyama,1989 ;Pérez-CoelloandDíaz- Maroto,2009 ;PridaandPuech,2006 ; Glabasniaand Thepurposeofthisworkwastoassessthequalityand Hofmann,2007 ). cooperagepotentialofthesetwoPortuguesewood speciesintoastedanduntoastedformonaccountof However,extensiveexploitationoftheabove- thegrowinginterestinalternativestotraditionaloak mentionedspecies,togetherwiththecurrentinterestin woodspeciesforcooperageinrecentyears. obtainingproductswithnovelsensoryproperties,has raisedtheneedtoseekeffectivealternativestothe MATERIALS AND METHODS traditionaloakwoodspecies.Recentstudieshave 1. Wood samples assessedthesuitabilityofchestnut( Castanea sativa ) and Quercus pyrenaica (anautochthonousoakspecies Seasonedandmedium-toastedchestnutwood oftheIberianPeninsula)foruseascooperage (C. sativa ) and oakwood( Q. pyrenaica ) collected materials.Informationonthechemicalcompositionof fromGerêsforests(Portugal)wereprovidedbyJ.M. thesespeciesisscant.Thevolatilecompositionof GonçalvesLdaCooperage(Palaçoulo).Thewood C. sativa and Q. pyrenaica woodfromSpainwas staveswerenaturallyseasonedinpilesoutsidefor recentlycomparedwiththatoftraditionaloakwood 24 months.Partofthestaveswassubmittedto speciesusedincooperage(Alañón et al. ,2012).The mediumtoast(160–170ºCfor30min).Bothseasoned influenceofgeographicallocation,siteand andmedium-toastedwoodsampleswerecutinto silviculturalvariablesonthevolatilecompositionof approximately4-mmthicksections,milledatroom Spanish Q. pyrenaica sampleswasalsoevaluated temperaturetopassa2-mmscreen,homogenisedand (Alañón et al. ,2011b).Basedontheresults,the thenkeptinadryatmosphereuntilanalysis. volatileprofileofboth C. sativa and Q. pyrenaica 2. Isolation of ellagitannins and low-molecular- providesanexcellentflavouringalternativeto weight (LMW) phenols from oak chips traditionaloakwoodspecies.Also,thephenolic compositionofFrenchchestnutwasrecently Fivehundredmilligramsofwoodchipswereextracted examinedbySanz et al. (2010). induplicatewith10mLofwater/acetone(3:7,v/v)at J. Int. Sci. Vigne Vin , 2013, 47 , n°4, 311-319 ©Vigne et Vin Publications Internationales (Bordeaux, France) - 312 - 05-castro_05b-tomazic 30/12/13 20:28 Page313 roomtemperaturewithconstantstirringfor180min. 20- µLaliquotsoforganicextractwereinjectedinto Then,2-mLaliquotswerefilteredthroughaMillipore HPLC.Theelutionconditionswereasfollows :flow membrane(porediameter0.45µm)basedonthe rate1mLmin –1 andtemperature30ºC.Twosolvents methoddescribedbyJordão et al. (2007).Thefiltrate wereusedforelution :A :H 2O/PO 4H3 (999 :1)and wasconcentratedundernitrogenstreaminorderto B:MeOH/PO 4H3 (999 :1).Alineargradientfrom0to removetheacetone. 100 %Bin50minwasused,basedonthemethod proposedbyFernándezdeSimón et al. (1999). Theresultingaqueousphasewasfractionatedby liquid-liquidextractionwith2mLofethylacetateand Peakidentificationswerebasedoncomparisonof 2mLofdiethyletherusingthemethoddevelopedby theirretentiontimeandUVspectrawiththoseofpure FernandezdeSimón et al. (1999).Bothphaseswere standards.Quantitativedeterminationswerecarried separatedafterfreezing.Theorganicphasewasdried outfromtheresultsoffourdeterminationsusing externalstandardcurvesofellagicacid.Resultsare inarotaryevaporator,redissolvedin1mLof –1 methanol,andinjected(20-µLaliquots)intoHPLCfor expressedinµgg ellagicacidequivalentsasabove. LMWphenoldetermination.Theaqueousphasewas 5. Statistical analysis adjustedto3mLwithbi-distilledwaterandinjected (20-µLaliquots)intoHPLCforellagitannin Analysisofvarianceandmultivariateanalyseswere determination. performedusingSPSS17.0forWindowsstatistical package.Differencesamongchemicaldatawere 3. HPLC analysis of ellagitannins assessedforsignificanceatP≤ 0.05usingthe Student–Newman–Keulstest. HPLCanalysiswascarriedoutona500BHPLC system(KonikInstrument,Spain)witha7176-LC RESULTS