Chapter-3活性包装.ppt

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1、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 Packagingisdescribedasactivewhenitperformssomedesiredroleotherthantoprovideaninertbarrierbetweentheproductandtheoutsideen

2、vironment.Activepackagingdiffersfromconventionalpassivepackaginginthatoneormoreformsofinteractionareplanned,usuallytooffsetadeficiencyinanotherwisesuitablepackage.3.1 DefinitionTheactivecomponentmaybepartofthepackagingmaterialormaybeaninsertorattachmenttotheinsideofthepack.Fromthe1980s,althoughthere

3、areexamplesthathavebeeninuseforoveracentury.TinplatecanAntioxidantreleasefromwaxed-paperpacksExamples,nextpage.EthyleneabsorbingproductBeFreshComparisonoforangesstoredwithandwithoutBeFreshfor14daysat77oF（=25）ComparisonofbroccolistoredwithandwithoutBeFreshfor5daysat77oFComparisonofbananasstoredwithan

4、dwithoutBeFreshfor5daysat77oFMSteam Are you interested in promoting Convenient&Healthy Microwavable Food Products?Msteamisourlatestactivepackagingdevelopment.ItoffersaneasytouseandsafesolutionforliddingapplicationsandalsoforuseinFFSpacksforen-papillote(inparchment)stylemicrowavecooking.Wecanofferara

5、ngeofsealinglayersinordertousematerialswithPP,PS,CPETtrays.ThefilmhasthebenefitofbeingSelfVentingandPeelablemakingthematerialsafeandeasytousefortheendcustomeri.e.thefilmavoidstheneedforacustomertopiercefilm.Key Benefits of using Alert Packaging MSteam:CooksfoodfromfrozenMaintains&preservesvitamins&m

6、ineralsinfoodNoneedtopiercefilmresultingincookingconsistencyPacksonexistingProductionlinesHermeticallysealed,maintainingthebarrieryourequireActivepackagingcanbeusedtominimizethedeteriorationofthepackagedproduct,whichcanoccurthroughbiologicalorphysicochemicalreactionmechanisms.3.2 Problems addressed

7、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 someprinti

8、ng inks,are oxidized on storage，friedsnacksoxidationandsoon.Biologicaldeteriorationresultfrominsectattack:Elevatedtemperaturesandhumiditiesen-hance the rate of activity at variousstagesinthelifecyclesofinsects.Chemical fumigation is becoming moretightlycontrolledwithfoods.Modified-atmosphere packagi

9、ng(MAP)isnowcommonlyusedinmanymarkets.Biological deterioration result from microbialgrowth:Grow at very low oxygen levels or in theabsenceofoxygen.Antimicrobialtreatmentssuchasthereleaseofcarbondioxide,ethanol,otherpreservatives,orfungicidescanplayaroleinreducingmicrobialgrowth.Desiccantscanassistin

10、reducingwateractivity.Condensationcontrolfilms.Biologicaldeteriorationoffreshproduce:Reductionintherateofsenescencecanbeachievedinmanycasesbyreductionoftherespirationratebyreducingequilibriumoxygenconcentrationsto2%.Ethylenereleasebyoneormoredamagedorripefruitcancauserapidripeningofothers.onerottena

11、ppleinthebarrelAerobic Aerobic RespirationRespirationAnaerobic Anaerobic RespirationRespirationRespirationRespiratory enzymeRespiratory enzymeOO2 2COCO2 2,H,H2 2OOEnergyEnergyAerobic RespirationAnaerobic ConditionAnaerobic ConditionCOCO2 2,Alcohol,AlcoholEnergyEnergyEnzymeEnzymeo o2 2Anaerobic Respi

12、rationChemicaldeterioration:Especiallyfoodsandbeverages(lipidandnutrientloss,off-flavorgeneration),butalsopharmaceuticals.Activepackagingcanbeusefulforoptimizingtheshelflife,whichoftenincludechemicallyandbiochemicallyactivecompoundsthatmaybesubjecttohydrolyticoroxidativedegradation.Chemicaldeteriora

13、tion:Industrialchemicalssuchasamines,andparticularlysomeprintinginks,areoxidizedonstorage.Oftentherateoflosscanbereducedadequatelybyinert-gasflushingandbarrierpackaging.Chemicalformsofin-packoxygenscavenginghavebeenintroducedtoreduceChemicaldeterioration:Friedsnacksareparticularlysusceptibletooxidat

14、ion,dependingontheirmoisturecontent.Thepresenceofoxygeninglassbottlesisusuallyoffsetbyadditionofsulfurdioxidetothebeverage.Thepresenceofanoxygenscavengerisrequired.(beerandWhiteWine)Chemicaldeterioration:Theflavorofsomefoodschangesonstoragebecauseofeffectsotherthanoxidation.Taintingisarecurrentprobl

15、em.Theseincludeaminesformedrapidlyinfishorrancidodorsinoil-containingfoods.Suchcompoundscanbepresentintraceamountsthataresignificantorganolepticallybutmaynotconstituteahealthhazard.Activepackagingischosentoenhancetheabilityofconventionalpackagingtohelpdelivertheproducttotheuserinadesiredstate.Thedec

16、isiontousesomeformofactivepackagingwilloftenbebasedononeormoreofthefollowingconsiderations: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-shel

17、f-lifeproductsmayrequireenhancementofonlyonepropertyforafixedperiod.Thiscanincludebakeryproducts,metal components shippedbysea,orchilledmeats.c)Simpler Processing.Introductionofadditionalmicrobiological“hurdles”canallowMAPtobeachievedwithoutuseexpensiveequipment.d)Reduction or Removal of Preservativ

18、es from Food Formulations.Thisisdonetomeetconsumerdemandsfor“fresher”foodscontainingfeweradditivesbytransferringpreservativesfromthefoodtothepackaging.e)Difficult-to-Handle Products.Oxygencanberemovedfromtightlypackagedproductssuchascheesesthataresubjecttomoldgrowth.f)Allowing Particular Types of Pa

19、ckages to be Used.Thiscouldinclude(a)retortableplasticpackagesforproductswithmultiyearshelflivesor(b)PETwinebottles.g)Presentation.Heatingbymicrowavesusceptorsandotheradjunctshasallowedpackaginginnovationforconveniencefoods.Themajorforminuseatpresentistheinsertionofsachetsofvariousscavengersoremitte

20、rs.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

21、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).Silicagelhasacapacitywhend

22、riedfortakingup40%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”andareoftenbetweentheprimaryandsecond

23、arypackage.Oxygen Scavengers:The contents ofoxygenscavengingsachetsdiffer,dependingontherelativehumidityoftheproduct,usuallyfood.3.4.1 Sachets and Other InsertsEthanol emitters:Lowconcentrationsofethanol,1-2%inbakeryproducts,havebeenshowntosuppressthegrowthofarangeofcommonmolds.Higherlevelsarenecess

24、arytosuppressbacteriaandyeasts,andtheeffectivenessisdependenttothewateractivityoftheproduct.3.4.1 Sachets and Other InsertsFreundCorp.(Japan)hasdevelopedtwoethanolemittingsachets,Antimold-mildTM(alsoknownasEthicap)andNegamoldTM,whichreleaseethanolvaporinresponsetotheabsorptionofwatervaporfromthefood

25、headspace.Antimold-mildTMsachetscontainfood-gradeethanol(55%)adsorbedinsilicapowder(85%).Ethicaphasbeeninvestigatedwithpitabread,appleturnovers,strawberrylayercakes,andMadeiraandcherrycreamcake.ItisusedwidelyinJapanwithsemimoistordryfishproducts.NegamoldTMsachetisnotwidelyused.Sulfur dioxide emitter

26、sSulfur-dioxide-releasingpadsareavailableforuseinthetransportationofcartonsoftablegrapes.3.4.1 Sachets and Other InsertsEthylene Absorbers Ethylene-absorbingsachets,sometimesmadeofsteelmesh,areavailableandfollowfromthevarietyofporousslabsandblanketsdevelopedforethyleneremovalincoolstoresandshippingc

27、ontainers.3.4.1 Sachets and Other InsertsEthylene AbsorbersSeveralmineralsareusedtocontainpotassiumpermanganateintheformofpurplebeadsorinothershapes.Typicalinertsubstratesincludeperlite,alumina,silicagel,andvermiculitecontaining4-6%potassiumpermanganate.3.4.1 Sachets and Other InsertsThereactionisas

28、follows: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-producingste

29、p,manyoftheintermediateproductsformedeitherbecomeirreversiblyboundtothemediaoractasreactantsthemselves.Suchisthecaseofthepotassiumhydroxide(KOH)formedinequation1and2.TheKOHwillreactwiththeaceticacidformedinequation2toproducethepotassiumacetatesalt(KCOOCH3)throughasimpleacid-baseneutralizationreactio

30、n.Thisisshownbelow.5.CH3COOH+KOH=KCOCH3+H2OCombiningequations1,2,and5weget:6.3CH2CH2+4KMnO4=3KCOOCH3+4MnO2+KOH+H2OOneapplicationtocomefromtheaboveistheuseofzeolitecoatedwithpotassiumpermanganateindomesticrefrigeratorstocontrolethylenebuild-upinvegetable.Ethylene AbsorbersEthylene-absorbingsachetsbas

31、edonotherprinciplesfordestructionoftheethylene,suchastheuseofcarbonactivatedwithapalladiumcatalyst,havealsobeenreported.3.4.1 Sachets and Other InsertsMoisture Control：Moistureinpackagesmaybeintheformofliquid(condensateordrip/weep)orasthevapor.Desiccantsremovebothformsofwater,althoughtheyaredesigned

32、toremovethevapor.3.4.2 Plastic-Based Active Packaging MaterialsMoisture Control：Thesimpleformofliquidmoisturesorptionhasbeenprovidedbydrip-absorbentsheetsconsistingoftwolayersofnonwovenpolyolefin,dividedbyheatsealsintopouchescontainingpolyacrylatesuperabsorbentpolymers.Thesesheetsareusedunderchicken

33、orturkeypiecesandsometimesunderredmeatstoabsorbdripduringdisplay.Otherusesaretoabsorbdripfromseafood,especiallywhenair-freightedtoavoidcorrosionofairframescausedbyspilling.3.4.2 Plastic-Based Active Packaging MaterialsMoisture ControlSuperabsorbentpolymerscanabsorbupto500timestheirownweightofwater,t

34、heydontfunctionassuchrapidabsorbentsforwatervapor.Awatervaporabsorbentsheet,knownasPichit,consistedofanenvelopeofpolyvinylalcoholfilmsandwichingaglycolandcarbohydrateinastrongwatervaporabsorber.3.4.2 Plastic-Based Active Packaging MaterialsOxygen ScavengingOxygen-scavengingfilmsorotherplasticmateria

35、lsoffertheopportunitytopreventoxygeningresstothepackagebypermeationaswellasremovingthatoriginallypresentinsidethepackage.Theyalsoofferthepotentialforpackagefabrication,filling,andsealingwithouttheneedforinsertionorattachmentofasachet.3.4.2 Plastic-Based Active Packaging MaterialsOxygen ScavengingOnl

36、yafewoxygen-scavengingfilmtechnologieshavebeencommercialized,suchasSealedAirslight-activatedCryovacOSSystem,whichisbasedonthetransitionmetal-catalyzedoxidationofrubber-likeunsaturatedpolymericcomponents.3.4.2 Plastic-Based Active Packaging MaterialsOxygen ScavengingThefirstthermoformableoxygen-scave

37、ngingsheet(Oxyguard)wascommercializedin1994byToyoSeikanKaishaLtd.foruseinretortableplasticstrays.TheoxygenscavenginglayerisbetweentheEVOH(ethylenevinylalcohol)oxygen-barrierlayerandtheinner,permeablepolypropylenelayer.(p7,Figure4)3.4.2 Plastic-Based Active Packaging MaterialsActive Oxygen BarriersMo

38、rerecently,oxygen-scavenginghasbeenusedtoimprovethebarrierperformanceofPETcontainers.PETbottleshavingenhancedoxygenbarrierpropertiesinclude:OxbarTM,AmosorbTM,ValORTM,Oxyblock(basedontheuseoftransition-metal-catalyzedoxidation)andActiTUF(basedoninvolvingincorporationofironparticlesintothePET).3.4.2 P

39、lastic-Based Active Packaging MaterialsAntimicrobial Films Antimicrobialagents,fungicides,andnaturalantagonistsareappliedtoharvestedproduceintheformofaqueousdipsoraswaxesorotherediblecoatings.Besidesproduce,foodswithcutsurfacesaresubjecttolargelysuperficialmicrobialattackandsomecheesesarepackagedwit

40、hwrappingsorseparatingfilmscontainingsorbicacid.3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobial Films SinanenZeomicCo.Ltd.inJapanproducesasyntheticzeolite,Zeomic,whichhassilverionsbondedintothesurfacelayersofthepores.Thezeolitehasbeenfoundtohighlyeffectiveagainstseveralvegetativebacteria

41、,especiallydispersedinwater,salinesolution,oroolongtea.ZeomicisapprovedasaFoodContactSubstancebytheUSFDAandcanbeusedinanytypeoffoodpackagingresinproduct.3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobial Films 3.4.2 Plastic-Based Active Packaging MaterialsAntimicrobialreleasingfilmsThePlaty

42、pus,anotherflexible“nylon/polyethylenefilm”bag-bottle,hasbeenaroundforyears,directedattheoutdoorandexercisecrowd,makingfornaturallymoreruggedconsiderations.Italsohasastandardpop-topspout,butalsoboastsanall-natural,silver-ion-basedSlimeGuardantimicrobialfilmtostaveoffbacteria.Itcanwithstandfreezingto

43、boilingtemps,butitsnotrecommendedfordishwashers.ThePlatypusalsohasareinforcedloopforattachingtoabeltorrope,andcomesinseveralsizeoptions,from.5Lto2L.Itscollapsibilitymakesit80%lighterandmorecompactthananemptyhardbottleofequalvolume.Odor Absorption:Molecularsievesandotheragentsareabletoabsorbodorousvo

44、latilecompounds.Packagingtechnologiescapableofremovingspecificclassesofodorouscompoundsthroughchemicalreactionhavealsobeeninvestigated.AdifferentapproachhasbeenpatentedbyMinatoSangyoCo.Ltd.,basedonascorbicacidandanironsaltdispersedintheplastic,andisaimedatremovingamineorsulfurcompoundsfromfishindome

45、sticrefrigerators.3.4.2 Plastic-Based Active Packaging MaterialsThermal Control Microwavablepackagescontainingfoodswithdifferingreheatingrequirementscanbemadetocrisporbrownsomecomponentsbyuseofsusceptorsandreducetheheatingofothercomponentsbyuseoffoilshields.Susceptorsnormallyconsistofavacuum-deposit

46、edlayerofaluminum,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”bymeansofchemi

47、calreactionsincompartmentsseparatedfromthebeverage.Sakeisheatedbytheexothermicreactionoflimewithwaterinaluminumcans.Coolingisachievedbytheendothermicdissolutionofammoniumnitrateandammoniumchlorideaboutbyshakingandthusareunsuitableforusewithcarbonatedbeverages.Thermal Control self-heating canisanenha

48、ncementofthecommonfoodcan.Self-heatingcanshavedualchambers,onesurroundingtheother.Theinnerchamberholdsthefoodordrink,andtheouterchamberhouseschemicalsthatundergoanexothermicreactionwhencombined.Whentheuserwantstoheatthecontentsofthecan,theypullaringonthecanthatbreaksthebarrierseparatingthechemicalsi

49、ntheouterchamber.Aftertheheatfromthereactionhasbeenabsorbedbythefood,theusercanenjoyahotmealordrink.Thermal Control Currentversionsoftheself-heatingcanworkinmuchthesameway,buthavethechemicalsintheinnerchamberandthebeveragesurroundingitintheouterchamber.Thisdesignhastheadvantagesofbeingmoreefficient(

50、lessheatislosttothesurroundingair)aswellasreducingexcessiveheatingoftheproductsexterior,causingpossiblediscomforttotheuser.Self-heatingcansofferbenefitstocampersandpeoplewithoutaccesstoamicrowaveoven,stoveorcamp-fire,butthetechnologyisnotyetcommon.Thisisbecauseself-heatingcansareconsiderablymoreexpe