Chapter-3活性包装.ppt
Chapter 3Active Packaging3.1 Definition3.2 Problems addressed by active packaging3.3 Goals of active packaging3.4 Forms of active packaging3.5 Research and development3.6 Summary Packagingisdescribedasactivewhenitperformssomedesiredroleotherthantoprovideaninertbarrierbetweentheproductandtheoutsideenvironment.Activepackagingdiffersfromconventionalpassivepackaginginthatoneormoreformsofinteractionareplanned,usuallytooffsetadeficiencyinanotherwisesuitablepackage.3.1 DefinitionTheactivecomponentmaybepartofthepackagingmaterialormaybeaninsertorattachmenttotheinsideofthepack.Fromthe1980s,althoughthereareexamplesthathavebeeninuseforoveracentury.TinplatecanAntioxidantreleasefromwaxed-paperpacksExamples,nextpage.EthyleneabsorbingproductBeFreshComparisonoforangesstoredwithandwithoutBeFreshfor14daysat77oF（=25）ComparisonofbroccolistoredwithandwithoutBeFreshfor5daysat77oFComparisonofbananasstoredwithandwithoutBeFreshfor5daysat77oFMSteam Are you interested in promoting Convenient&Healthy Microwavable Food Products?Msteamisourlatestactivepackagingdevelopment.ItoffersaneasytouseandsafesolutionforliddingapplicationsandalsoforuseinFFSpacksforen-papillote(inparchment)stylemicrowavecooking.WecanofferarangeofsealinglayersinordertousematerialswithPP,PS,CPETtrays.ThefilmhasthebenefitofbeingSelfVentingandPeelablemakingthematerialsafeandeasytousefortheendcustomeri.e.thefilmavoidstheneedforacustomertopiercefilm.Key Benefits of using Alert Packaging MSteam:CooksfoodfromfrozenMaintains&preservesvitamins&mineralsinfoodNoneedtopiercefilmresultingincookingconsistencyPacksonexistingProductionlinesHermeticallysealed,maintainingthebarrieryourequireActivepackagingcanbeusedtominimizethedeteriorationofthepackagedproduct,whichcanoccurthroughbiologicalorphysicochemicalreactionmechanisms.3.2 Problems addressed by active packagingTwo main kinds of deteriorationBiological deterioration:may resultfrom insect attack,may cause bymicrobial growth and fresh producessenescence.Chemical deterioration:foodcomponentshydrolysis,industrialchemical oxidation Industrial chemicalsuch as amines,and particularly someprinting inks,are oxidized on storage，friedsnacksoxidationandsoon.Biologicaldeteriorationresultfrominsectattack:Elevatedtemperaturesandhumiditiesen-hance the rate of activity at variousstagesinthelifecyclesofinsects.Chemical fumigation is becoming moretightlycontrolledwithfoods.Modified-atmosphere packaging(MAP)isnowcommonlyusedinmanymarkets.Biological deterioration result from microbialgrowth:Grow at very low oxygen levels or in theabsenceofoxygen.Antimicrobialtreatmentssuchasthereleaseofcarbondioxide,ethanol,otherpreservatives,orfungicidescanplayaroleinreducingmicrobialgrowth.Desiccantscanassistinreducingwateractivity.Condensationcontrolfilms.Biologicaldeteriorationoffreshproduce:Reductionintherateofsenescencecanbeachievedinmanycasesbyreductionoftherespirationratebyreducingequilibriumoxygenconcentrationsto2%.Ethylenereleasebyoneormoredamagedorripefruitcancauserapidripeningofothers.onerottenappleinthebarrelAerobic Aerobic RespirationRespirationAnaerobic Anaerobic RespirationRespirationRespirationRespiratory enzymeRespiratory enzymeOO2 2COCO2 2,H,H2 2OOEnergyEnergyAerobic RespirationAnaerobic ConditionAnaerobic ConditionCOCO2 2,Alcohol,AlcoholEnergyEnergyEnzymeEnzymeo o2 2Anaerobic RespirationChemicaldeterioration:Especiallyfoodsandbeverages(lipidandnutrientloss,off-flavorgeneration),butalsopharmaceuticals.Activepackagingcanbeusefulforoptimizingtheshelflife,whichoftenincludechemicallyandbiochemicallyactivecompoundsthatmaybesubjecttohydrolyticoroxidativedegradation.Chemicaldeterioration:Industrialchemicalssuchasamines,andparticularlysomeprintinginks,areoxidizedonstorage.Oftentherateoflosscanbereducedadequatelybyinert-gasflushingandbarrierpackaging.Chemicalformsofin-packoxygenscavenginghavebeenintroducedtoreduceChemicaldeterioration:Friedsnacksareparticularlysusceptibletooxidation,dependingontheirmoisturecontent.Thepresenceofoxygeninglassbottlesisusuallyoffsetbyadditionofsulfurdioxidetothebeverage.Thepresenceofanoxygenscavengerisrequired.(beerandWhiteWine)Chemicaldeterioration:Theflavorofsomefoodschangesonstoragebecauseofeffectsotherthanoxidation.Taintingisarecurrentproblem.Theseincludeaminesformedrapidlyinfishorrancidodorsinoil-containingfoods.Suchcompoundscanbepresentintraceamountsthataresignificantorganolepticallybutmaynotconstituteahealthhazard.Activepackagingischosentoenhancetheabilityofconventionalpackagingtohelpdelivertheproducttotheuserinadesiredstate.Thedecisiontousesomeformofactivepackagingwilloftenbebasedononeormoreofthefollowingconsiderations:3.3 Goals of active packaginga)Extension of Shelf Life.Thisextension may exceed the presentlyacceptedlimits as with sea shipmentofsomefreshproduce.b)Less Expensive Packaging Materials.Packaging of limited-shelf-lifeproductsmayrequireenhancementofonlyonepropertyforafixedperiod.Thiscanincludebakeryproducts,metal components shippedbysea,orchilledmeats.c)Simpler Processing.Introductionofadditionalmicrobiological“hurdles”canallowMAPtobeachievedwithoutuseexpensiveequipment.d)Reduction or Removal of Preservatives from Food Formulations.Thisisdonetomeetconsumerdemandsfor“fresher”foodscontainingfeweradditivesbytransferringpreservativesfromthefoodtothepackaging.e)Difficult-to-Handle Products.Oxygencanberemovedfromtightlypackagedproductssuchascheesesthataresubjecttomoldgrowth.f)Allowing Particular Types of Packages to be Used.Thiscouldinclude(a)retortableplasticpackagesforproductswithmultiyearshelflivesor(b)PETwinebottles.g)Presentation.Heatingbymicrowavesusceptorsandotheradjunctshasallowedpackaginginnovationforconveniencefoods.Themajorforminuseatpresentistheinsertionofsachetsofvariousscavengersoremitters.Thesehavebeenfollowedmorerecentlybyplasticsblendsorcompoundsand,toalesserextent,bycompositepackagesofvariousforms.3.4 Forms of active packaging 3.4.1 Sachets and Other Inserts(Desiccants,OxygenScavengers,Ethanolemitters,Sulfurdioxideemitters,EthyleneAbsorbers)3.4.2 Plastic-Based Active Packaging Materials(Moisture Control,Oxygen Scavenging,Active Oxygen Barriers,Antimicrobial Films,OdorAbsorption,ThermalControl)*3.4.3 Microwave Susceptors*3.4.4 Humidity Indicator Cards 3.4.1 Sachets and Other InsertsDesiccants:Commonlyuseddesiccantaresilicagelandlime(calciumoxide).Silicagelhasacapacitywhendriedfortakingup40%ofitsownweightofwatervapor.Lime(calcium oxide)takes up 28%.Both are usedlargely in the shipment of goods through humidatmospherestoprotectagainstcorrosion(steel),caking(pharmaceuticals),or mold growth(foods).DesiccantSachetsaremarked“Do not eat”andareoftenbetweentheprimaryandsecondarypackage.Oxygen Scavengers:The contents ofoxygenscavengingsachetsdiffer,dependingontherelativehumidityoftheproduct,usuallyfood.3.4.1 Sachets and Other InsertsEthanol emitters:Lowconcentrationsofethanol,1-2%inbakeryproducts,havebeenshowntosuppressthegrowthofarangeofcommonmolds.Higherlevelsarenecessarytosuppressbacteriaandyeasts,andtheeffectivenessisdependenttothewateractivityoftheproduct.3.4.1 Sachets and Other InsertsFreundCorp.(Japan)hasdevelopedtwoethanolemittingsachets,Antimold-mildTM(alsoknownasEthicap)andNegamoldTM,whichreleaseethanolvaporinresponsetotheabsorptionofwatervaporfromthefoodheadspace.Antimold-mildTMsachetscontainfood-gradeethanol(55%)adsorbedinsilicapowder(85%).Ethicaphasbeeninvestigatedwithpitabread,appleturnovers,strawberrylayercakes,andMadeiraandcherrycreamcake.ItisusedwidelyinJapanwithsemimoistordryfishproducts.NegamoldTMsachetisnotwidelyused.Sulfur dioxide emittersSulfur-dioxide-releasingpadsareavailableforuseinthetransportationofcartonsoftablegrapes.3.4.1 Sachets and Other InsertsEthylene Absorbers Ethylene-absorbingsachets,sometimesmadeofsteelmesh,areavailableandfollowfromthevarietyofporousslabsandblanketsdevelopedforethyleneremovalincoolstoresandshippingcontainers.3.4.1 Sachets and Other InsertsEthylene AbsorbersSeveralmineralsareusedtocontainpotassiumpermanganateintheformofpurplebeadsorinothershapes.Typicalinertsubstratesincludeperlite,alumina,silicagel,andvermiculitecontaining4-6%potassiumpermanganate.3.4.1 Sachets and Other InsertsThereactionisasfollows:1.3CH2CH2+2KMnO4+H2O=2MnO2+3CH3CHO+2KOH2.3CH3CHO+2KMnO4+H2O=3CH3COOH+2MnO2+2KOH3.3CH3COOH+8KMnO4=6CO2+8MnO2+8KOH+2H2OCombiningequations1-3,weget:4.3CH2CH2+12KMnO4=12MnO2+12KOH+6CO2ietheethyleneisoxidisedtocarbondioxide.Evenifthereactiondoesnotgoallthewaythroughtothecarbondioxide-producingstep,manyoftheintermediateproductsformedeitherbecomeirreversiblyboundtothemediaoractasreactantsthemselves.Suchisthecaseofthepotassiumhydroxide(KOH)formedinequation1and2.TheKOHwillreactwiththeaceticacidformedinequation2toproducethepotassiumacetatesalt(KCOOCH3)throughasimpleacid-baseneutralizationreaction.Thisisshownbelow.5.CH3COOH+KOH=KCOCH3+H2OCombiningequations1,2,and5weget:6.3CH2CH2+4KMnO4=3KCOOCH3+4MnO2+KOH+H2OOneapplicationtocomefromtheaboveistheuseofzeolitecoatedwithpotassiumpermanganateindomesticrefrigeratorstocontrolethylenebuild-upinvegetable.Ethylene AbsorbersEthylene-absorbingsachetsbasedonotherprinciplesfordestructionoftheethylene,suchastheuseofcarbonactivatedwithapalladiumcatalyst,havealsobeenreported.3.4.1 Sachets and Other InsertsMoisture Control：Moistureinpackagesmaybeintheformofliquid(condensateordrip/weep)orasthevapor.Desiccantsremovebothformsofwater,althoughtheyaredesignedtoremovethevapor.3.4.2 Plastic-Based Active Packaging MaterialsMoisture Control：Thesimpleformofliquidmoisturesorptionhasbeenprovidedbydrip-absorbentsheetsconsistingoftwolayersofnonwovenpolyolefin,dividedbyheatsealsintopouchescontainingpolyacrylatesuperabsorbentpolymers.Thesesheetsareusedunderchickenorturkeypiecesandsometimesunderredmeatstoabsorbdripduringdisplay.Otherusesaretoabsorbdripfromseafood,especiallywhenair-freightedtoavoidcorrosionofairframescausedbyspilling.3.4.2 Plastic-Based Active Packaging MaterialsMoisture ControlSuperabsorbentpolymerscanabsorbupto500timestheirownweightofwater,theydontfunctionassuchrapidabsorbentsforwatervapor.Awatervaporabsorbentsheet,knownasPichit,consistedofanenvelopeofpolyvinylalcoholfilmsandwichingaglycolandcarbohydrateinastrongwatervaporabsorber.3.4.2 Plastic-Based Active Packaging MaterialsOxygen ScavengingOxygen-scavengingfilmsorotherplasticmaterialsoffertheopportunitytopreventoxygeningresstothepackagebypermeationaswellasremovingthatoriginallypresentinsidethepackage.Theyalsoofferthepotentialforpackagefabrication,filling,andsealingwithouttheneedforinsertionorattachmentofasachet.3.4.2 Plastic-Based Active Packaging MaterialsOxygen ScavengingOnlyafewoxygen-scavengingfilmtechnologieshavebeencommercialized,suchasSealedAirslight-activatedCryovacOSSystem,whichisbasedonthetransitionmetal-catalyzedoxidationofrubber-likeunsaturatedpolymericcomponents.3.4.2 Plastic-Based Active Packaging MaterialsOxygen ScavengingThefirstthermoformableoxygen-scavengingsheet(Oxyguard)wascommercializedin1994byToyoSeikanKaishaLtd.foruseinretortableplasticstrays.TheoxygenscavenginglayerisbetweentheEVOH(ethylenevinylalcohol)oxygen-barrierlayerandtheinner,permeablepolypropylenelayer.(p7,Figure4)3.4.2 Plastic-Based Active Packaging MaterialsActive Oxygen BarriersMorerecently,oxygen-scavenginghasbeenusedtoimprovethebarrierperformanceofPETcontainers.PETbottleshavingenhancedoxygenbarrierpropertiesinclude:OxbarTM,AmosorbTM,ValORTM,Oxyblock(basedontheuseoftransition-metal-catalyzedoxidation)andActiTUF(basedoninvolvingincorporationofironparticlesintothePET).3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobial Films Antimicrobialagents,fungicides,andnaturalantagonistsareappliedtoharvestedproduceintheformofaqueousdipsoraswaxesorotherediblecoatings.Besidesproduce,foodswithcutsurfacesaresubjecttolargelysuperficialmicrobialattackandsomecheesesarepackagedwithwrappingsorseparatingfilmscontainingsorbicacid.3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobial Films SinanenZeomicCo.Ltd.inJapanproducesasyntheticzeolite,Zeomic,whichhassilverionsbondedintothesurfacelayersofthepores.Thezeolitehasbeenfoundtohighlyeffectiveagainstseveralvegetativebacteria,especiallydispersedinwater,salinesolution,oroolongtea.ZeomicisapprovedasaFoodContactSubstancebytheUSFDAandcanbeusedinanytypeoffoodpackagingresinproduct.3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobial Films 3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobialreleasingfilmsThePlatypus,anotherflexible“nylon/polyethylenefilm”bag-bottle,hasbeenaroundforyears,directedattheoutdoorandexercisecrowd,makingfornaturallymoreruggedconsiderations.Italsohasastandardpop-topspout,butalsoboastsanall-natural,silver-ion-basedSlimeGuardantimicrobialfilmtostaveoffbacteria.Itcanwithstandfreezingtoboilingtemps,butitsnotrecommendedfordishwashers.ThePlatypusalsohasareinforcedloopforattachingtoabeltorrope,andcomesinseveralsizeoptions,from.5Lto2L.Itscollapsibilitymakesit80%lighterandmorecompactthananemptyhardbottleofequalvolume.Odor Absorption:Molecularsievesandotheragentsareabletoabsorbodorousvolatilecompounds.Packagingtechnologiescapableofremovingspecificclassesofodorouscompoundsthroughchemicalreactionhavealsobeeninvestigated.AdifferentapproachhasbeenpatentedbyMinatoSangyoCo.Ltd.,basedonascorbicacidandanironsaltdispersedintheplastic,andisaimedatremovingamineorsulfurcompoundsfromfishindomesticrefrigerators.3.4.2 Plastic-Based Active Packaging MaterialsThermal Control Microwavablepackagescontainingfoodswithdifferingreheatingrequirementscanbemadetocrisporbrownsomecomponentsbyuseofsusceptorsandreducetheheatingofothercomponentsbyuseoffoilshields.Susceptorsnormallyconsistofavacuum-depositedlayerofaluminum,typicallywithalighttransmissionof50-60%,ora12-m-thickfilmofbiaxiallyorientedPET.3.4.2 Plastic-Based Active Packaging MaterialsMachine Direction OrientationCross Direction OrientationThermal Control(another form)Beveragecanscanbemadeeither“self-heating”or“self-cooling”bymeansofchemicalreactionsincompartmentsseparatedfromthebeverage.Sakeisheatedbytheexothermicreactionoflimewithwaterinaluminumcans.Coolingisachievedbytheendothermicdissolutionofammoniumnitrateandammoniumchlorideaboutbyshakingandthusareunsuitableforusewithcarbonatedbeverages.Thermal Control self-heating canisanenhancementofthecommonfoodcan.Self-heatingcanshavedualchambers,onesurroundingtheother.Theinnerchamberholdsthefoodordrink,andtheouterchamberhouseschemicalsthatundergoanexothermicreactionwhencombined.Whentheuserwantstoheatthecontentsofthecan,theypullaringonthecanthatbreaksthebarrierseparatingthechemicalsintheouterchamber.Aftertheheatfromthereactionhasbeenabsorbedbythefood,theusercanenjoyahotmealordrink.Thermal Control Currentversionsoftheself-heatingcanworkinmuchthesameway,buthavethechemicalsintheinnerchamberandthebeveragesurroundingitintheouterchamber.Thisdesignhastheadvantagesofbeingmoreefficient(lessheatislosttothesurroundingair)aswellasreducingexcessiveheatingoftheproductsexterior,causingpossiblediscomforttotheuser.Self-heatingcansofferbenefitstocampersandpeoplewithoutaccesstoamicrowaveoven,stoveorcamp-fire,butthetechnologyisnotyetcommon.Thisisbecauseself-heatingcansareconsiderablymoreexpe
