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第页原文题目：ConcentrationofflavonoidsandphenoliccompoundsinaqueousandethanolicpropolisextractsthroughnanofiltrationAbstractPropolishasavariableandcomplexchemicalcompositionwithhighconcentrationofflavonoidsandphenoliccompoundspresentintheextract.Theextractvarieswiththesolventusedinextraction.Ethanolextractsmorephenolicacidandpolarcompoundsthanwater.Beforetheiruseinindustry,extractsmustbeconcentratedbuttheuseofhightemperaturescandegradesomecompounds.Membranepro-cessesisanoptionthatallowsconcentrationatlowtemperatures.Nanofiltrationwascarriedoutwithaqueousandethanolicextractsandeachextractresultsintwodistinctfractions:permeateandretentate.Thecapacityofthemembranetoretainthecompoundswasverifiedbyspectrophotometricanalysis:foraqueoussolution,themembraneretainedaround94%ofthephenoliccompoundsand99%oftheflavonoids,whilefortheethanolicsolutionthesevalueswere53%and90%,respectively.Ferulicacidretentionindexwas1.00and0.88toaqueousandethanolicsolutions,respectively.Thus,thenanofiltrationprocessshowedhighefficiencyintheconcentrationofpropolisextracts.1IntroductionOverthelastfewdecades,interestinfunctionalfoodshasbeengrowingfast,leadingtothediscoveryofnewfunctionalcomponentsorprocessesthatcanimprovefoodprocessing,aswellasproductsthatmayhelptoretardagingoravoiddiseases.Inthiscontext,beeproductshavegainedtheattentionofconsumersandresearchers,duetotheirchemicalcompositionsandfunctionalproperties.Propolisisoneofthebeeproductswithfunctionalproperties,butitcannotbeconsumedasafoodbecauseitisaresinoussubstance.Itispreparedfromthebudsandexudatesofcertaintreesandplants.Thesesubstancesaretransformedbytheadditionofwaxandtheenzymeglucosidasepresentinthebeesalivainordertoformpropolis(Bankovaetal.,2000;Parketal.,1998).Theproductobtainedisusedbyhoneybeestoprotectthehivesagainstinvadersandcontamination,tosealholesandtomaintainthetemperature.Someimportantcharacteristicshavebeenreportedforthissubstance,suchasanti-microbialandantioxidanteffects,anestheticpropertiesandothers.Duetothesecharacteristics,whichc
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