ValidationofFood PreservationProcesses BasedonNovel Technologies
Editedby TATIANAKOUTCHMA
GuelphResearchandDevelopmentCenter,Agriculture andAgri-FoodCanada,ON,Canada
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1.Generalprinciplesandapproachesoffoodprocessvalidation1
TatianaKoutchmaandLarryKeener
1.1 Generalprinciplesandapproachesoffoodprocessvalidation1
1.1.1 Validationconceptandterminology1
1.1.2 Verificationversusvalidationversusmonitoring5
1.1.3 Validationatdifferentphasesofprocessdevelopment6
1.1.4 Scale-upprocess7
1.1.5 Keycomponentsofvalidationprocedures9
1.1.6 Physicalvalidation9
1.1.7 Microbiologicalvalidation10
1.1.8 Qualityvalidation18
1.1.9 Equipmentvalidation21
1.1.10 Cleaningandsanitationvalidation22
1.1.11 Facilityrequirements23
1.1.12 Documentation24
1.1.13 Roleofprocessauthorityintheeraofemergentnoveland nonthermalpreservationtechnologies24
1.1.14 Requirementsforprocessingauthorities[21CFR113.83and113.89]26
1.2 Conclusions29 References29
2.Validationofhighhydrostaticpressureprocess31
TatianaKoutchmaandKeithWarriner
2.1 Historyandintroductiontohigh-pressureprocessingtechnology forfoods31
2.2 FundamentalsofHHP32
2.2.1 HHPprincipleofoperation32
2.2.2 HHPcommercialapplications33
2.2.3 HHPmicrobiologicaleffects35
2.2.4 HHPqualityeffects41
2.2.5 HHPeffectsonallergens42
2.2.6 HHPeffectsonpatulinmycotoxin42
2.2.7 HHPeffectsonenzymes44
2.3 HHPcriticalproductandprocessparameters44
2.3.1 Productparameters44
2.3.2 Processparameters51
2.4 Packaging56
2.4.1 Requirementsandtypesofpackages56
2.4.2 Foodcontactcompliance59
2.4.3 Packagingvalidation59
2.5 HHPcommercialsystems60
2.5.1 Design60
2.5.2 Pressurevessels60
2.5.3 CommercialHHPmanufacturers62
2.5.4 Scalabilityofpilotandcommercial-scaleHHPprocesses66
2.5.5 CalibrationandmaintenanceofHHPsystems68
2.6 Internationalregulatoryrequirements69
2.6.1 AustraliaandNewZealand69
2.6.2 Canada71
2.6.3 EuropeanUnion72
2.6.4 UnitedStates73
2.7 Microbiologicalchallengetesting74
2.7.1 Shelf-lifevalidation77
2.7.2 Safetyvalidation79
2.7.3 Surrogateorganisms81
2.8 CommercialHHPtrials84
2.8.1 Juices84
2.8.2 Meats86
2.8.3 Delisalads,hashbrowns,herbs,andgravybase88
2.9 ResponsibilitiesforcontractofHHPfacility89
2.9.1 Deviationfromthevalidatedprocess90
2.10 FutureprospectsandgapsinHHPtechnologydevelopment90 References91 Furtherreading97
3.Casestudyofvalidationofhighhydrostaticpressureprocessing offruitandvegetablesmoothiesinPETbottles99
TatianaKoutchmaandKeithWarriner
3.1 Productdescription99
3.2 Packaging99
3.3 HPPunit100
3.4 Methodology100
3.5 Samplingplan100
3.6 Testprocedures102
3.7 Sourceofpathogens102
3.8 Cultivation,enumeration,andenrichmentprotocolsformodelmicrobes103
3.9 HPPoperationprocedure105
3.10 Results106
3.11 Conclusion112 References112
4.Validationoflight-basedprocesses113
TatianaKoutchma
4.1 Historyandintroductiontofundamentalsofultravioletlightandpulsed lighttechnologyforfoodapplications113
4.2 ContinuousUV,pulsed,andLEDlightsources115
4.3 Internationalregulatoryrequirements118
4.3.1 USFoodandDrugAdministration:foodadditiveapproach118
4.3.2 Novelfoodregulations122
4.4 ValidationofUVlighttechnologiesforsurfacetreatment123
4.4.1 UVdisinfectionefficiencyofsurfacesandlimitingfactors124
4.4.2 Advantagesanddisadvantagesofhigh-intensitypulses126
4.4.3 Establishingstepsandvalidationofsurfacetreatmentprocess126
4.4.4 Criticalprocessandcontrolparameters130
4.4.5 CommercialUVandpulsedlightsystemsforsurfacetreatment130
4.4.6 CasestudiesofpulsedandcontinuousUVsurfacetreatment131
4.5 ValidationofUVlightpreservationprocessesforliquidproducts andbeverages133
4.5.1 RequirementsforUVCpreservationofbeverages134
4.5.2 EstablishmentofpreservationreductionequivalentUVCdose137
4.5.3 PrinciplesofvalidationofUVCpreservationprocessforliquids andbeverages141
4.5.4 ValidationofcommercialUVequipmentandprocesscontrols160
4.6 Conclusion165 References165
5.Casestudyofvalidationofultravioletlightpasteurizationof sugarsyrups169
TatianaKoutchma
5.1 Evaluationofultravioletdoseincommercialultravioletsystem169
5.1.1 Experimentalapproach169
5.1.2 Results176
5.1.3 MathematicalmodelingofUVfluencerate184
5.1.4 Conclusions191
5.2 UVdoseverificationstudiesincommercial-scalesystem192
5.2.1 Background192
5.2.2 Materialsandmethodologies193
5.2.3 Results198
5.2.4 Conclusion207
5.3 UVinactivationofpathogenicandspoilageorganismsinliquidsucrose207
5.3.1 Methodology208
5.3.2 Results210
5.3.3 Conclusions213 References214
6.Overviewofothernovelprocessesandvalidationapproaches215 TatianaKoutchma
6.1 Introduction215
6.2 Radiation,regulations,andvalidation215
6.2.1 Gammarays216
6.2.2 X-raysande-beams217
6.2.3 Safetyofirradiation218
6.2.4 Validationandverificationoffoodirradiationprocess218
6.2.5 Irradiationfacility221
6.2.6 Internationalregulationsandstandards221
6.3 Advancedradiativeandelectromagneticheatingtechnologies223
6.3.1 Infrared224
6.3.2 Ohmic224
6.3.3 Magneticinduction225
6.3.4 Microwave226
6.3.5 Radiofrequency226
6.3.6 Validationprinciplesofmicrowaveandradiofrequencyheating229
6.4 Coldatmosphericplasma235
6.4.1 Validationchallenges236
6.4.2 Regulationsandcommercialization238 References239 Conclusions241 Index 247
Listofcontributors
LarryKeener
InternationalProductSafetyConsultants,Seattle,WA,UnitedStates
TatianaKoutchma
NovelFoodProcessingTechnologies,AgricultureandAgri-FoodCanada,Guelph, ON,Canada
KeithWarriner
FoodScienceDepartment,UniversityofGuelph,Guelph,ON,Canada;Centerfor PublicHealthandZoonosesCanada
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Preface
Withthefast-growingdemandsinmildheatandcoldfoodpreservation andsanitationmarkets,novelprocessingtechnologieshavebeenemerging infoodproductionforextendingproducts’ shelf-lifeandeliminating foodbornepathogens.Ascience-basedstandardizedvalidationprocessisa criticalcomponentinassessingtheefficacyofnoveltechnologiesasa microbialcontrolmeasureaccordingtofoodregulationsandsuccessful commercialization.Whilethelongerhistoryofvalidationofthermaltechnologiesresultedinadvancingstandardmethodologies,theapproachesfor thevalidationofnonthermaltechnologiesarenotestablishedandarecurrentlyunderdevelopment.Amonganumberoftechnologiesthatare presentlyinvestigatedforpremiumfoodprocessing,highhydrostaticpressure(HHP)andultraviolet(UV-C)lightarenonthermalalternativesto pasteurizationapprovedbyinternationalregulatoryagenciesandrecognizedasthesimplestandenvironmentallyfriendlywaystodestroypathogenicandspoilageorganismswithlowerimpactonqualityandnutrition valuesandsensoryattributesofmanyproducts.
Despitenumerouspublicationsthatareavailableonscientific,technological,andengineeringaspectsofnonthermalprocessingapplicationsfor foodtreatment,norecentmonographexiststhatwouldintegratefundamentalknowledgeaboutprinciplesandscientificapproachesoffoodprocessvalidationonallstagesofprocessdevelopmentand commercialization.Theneedforclearknowledgeandunderstandingof validationstepsofnonthermalprocessesisvital.Thisbookisafirst attempttosummarizeexistingscientificexperienceofvalidationoftraditionalthermalandnonthermaltechnologies,suchascanningorradiation, andrecommendkeyactivitiesforbenchtop,pilot,prototype,andcommercialvalidationofHPPandUVsystemsforthetreatmentofvarietyof foodproducts.Theobjectiveandfocusofthismanuscriptistoreview definitions,principles,andpracticalapproachesoffoodprocessvalidation andsummarizetheexperienceofthermalprocessingandofafewcommerciallyavailablenovelprocessesthathavebeenusingHPPtechnology, recentlyultravioletlightandothernoveltechnologiesforsafetyandpreservationoperations.Theaspectsexploredincludeavailableprocessapplicationsforliquidandsolidfoods,criticalproductandprocesscontrol parametersforeachtechnology,microbialchallengestudiesincluding
selectionandrecommendationofsurrogates,andconsiderationforprocedurestomeasureandcontrolthedeliveryoftherequirednovelprocess, quality,andequipmentvalidation.Inaddition,sanitarydesignandequipmentscalabilitywillbediscussedtofacilitatetheimplementationofnonthermaltechnologiesandmitigaterisksduringfoodproduction.
Theintroductionchapterstartswithreexaminingthehistoryofthermalprocessvalidationandverificationandexistingpracticalmethodsand approachesofthermalpreservationprocessestablishmentandvalidation. Also,newchallengesofdevelopment,validation,andcommercialimplementationofnovelnonthermalprocessescomparedtothermalprocessing areoutlinedincludingproductionbenefitsandreviewoffundamental principles.
In Chapter1,GeneralPrinciplesandApproachesofFoodProcess Validation,generalconceptanddefinitions,structure,keycomponents, andapproachestoprocessvalidationarepresentedanddiscussedindetail. Thisincludesphysical,microbiologicalsafety,quality,andequipmentvalidationwithelementsofcleaning,calibrationandanalyticalparts,andvalidationoffacilities.Thegeneralguidelinesforeachkeycomponentofthe validationprocessaregivenalongwiththebasicoutlineofobjectivesand criticalproceduresofprocessandequipmentvalidation.Essentialroleand requirementsforprocessauthorityarepresentedinthischapter.
Thefocusof Chapter2,ValidationofHighHydrostaticPressure Process,isthevalidationofHHPprocessofHPPthatisusedfornonthermalpasteurization.ThefundamentalprinciplesofHPPalongwithessentialpracticalconsiderationsintermsofcriticalproductandprocess parameters,packaging,microbialchallengestudies,andothertestingand scalingupissuesarediscussedindetailstoassistHPPenduserstoaccelerateprocessinnovation.
Thegoalof Chapter3,CaseStudyofValidationofHighHydrostatic PressureProcessingofFruitandVegetableSmoothiesinPETBottles. Chapter4 istodiscussValidationofLight-BasedProcesses,suchascontinuousUV-Clight,pulsedlight,andLEDs,forthetreatmentofsurfaces andliquidproductsandprovideguidelinesfortechnologyimplementation.Informationregardinginternationalregulatoryrequirementsonlight technologiesissummarizedandwillbehelpfulindeterminingvalidation objectivesandscope. Chapter5,CaseStudyofValidationofUltraviolet LightPasteurizationofSugarSyrups,presentsthemethodologyandvalidationofmicrobiologicalefficacyofcommercialUVtreatmentofsugar syrups.
Chapter6,OverviewofOtherNovelProcessesandValidation Approaches,isfocusedontheoverviewandbriefdiscussionofprinciples, commercialapplications,andmainvalidationapproachesoftwocommerciallyavailablegroupoftechnologies,suchasionizingirradiationand advancedmicrowaveheatingandemergingtreatmentusingcoldatmosphericplasma.Prosandconsofeachtechnologywillbepresentedalong withstatusupdateonregulatoryapprovalsandvalidationprocedures.Due tothephysicalnatureofthosetechnologies,theapproachesforprocess validationdifferandfacedifferenttechnicalchallenges.Forthisreason, differentapproachescanbeusedtodemonstrateanddocumentthetargetedperformance.
Notallnonthermaltechnologiesandvalidationissueswerediscussed inthisbook.Ingeneral,thebookcontentisaimedtoassistandprovide recommendationsforfoodprocessors,technologydevelopers,equipment manufacturers,regulatoryinspectors,andextensionspecialistsduringthe commercializationofnoveltechnologies.Moreover,thesuggestionsfor validationprotocolsandreportscanbehelpfulforintendedaudience. However,thisbookrepresentsthemostcomprehensiveandambitious steponthesubjectofvalidationofnoveltechnologiesforfoodsthatexists todate.Also,theimportantstepforwardhasbeenmadeinscientific understandingoftheneedsandpracticaltasksforthefuture.
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Introduction TatianaKoutchma
NovelFoodProcessingTechnologies,AgricultureandAgri-FoodCanada,Guelph,ON,Canada
1.Historyofthermalprocessvalidationandverification
1.1Approachestothermalprocessvalidation
Throughoutthehistoryoffoodprocessing,theapplicationofpreservation technologieshasbeentraditionallyassociatedwithfourfundamental concepts:
1. Applicationofthermalenergytoelevateproducttemperaturesto achievelong-termorextendedsafety,stability,orpreservation;
2. Removalofthermalenergytoreduceproducttemperatureandextend shelf-life;
3. Removalofwaterfromproductstructureortoacidifyfoodsandthus achieveanextendedshelf-life;
4. Applicationofpackagingorasteprequiredformaintainingofproduct propertiesachievedafterprocessingduringstorage.
Theapplicationofthermalenergytoelevatetheproducttemperature hasbeenoneofthekeyprocessesinthefood-processingindustry,which oftenaimstoproducecommerciallysterilefoodproductsandpasteurized productsofoptimalquality.
Dependingontheproducttype solidorliquid beingprocessedand theshelf-liferequired,thermalpreservationcanbeaccomplishedintwo ways.Inthecaseofsolidfoods,heatisappliedtoafilled,sealedcontainer, andinthecaseofliquids,thesterilizationorpasteurizationofproducts cantakeplaceoutsideoftheirfinalcontainerandbeforefillinginaclean orasepticenvironment.
Sterilizationandpasteurizationoperationsrely,respectively,oneliminationandreductionofthemostresistantpathogensofpublichealthsignificanceandspoilagemicroflora.Commercialsterilityisdefinedas:the conditionachievedbyapplicationofheatwhichrendersfoodfreefrom viablemicroorganisms,includingthoseofknownpublichealthsignificance,capableofgrowinginthefoodatthetemperaturesatwhichthe foodislikelytobeheldduringdistributionandstorage(USDepartment ofHealth,1994).Theterm “pasteurization” wasoriginallydefinedasa
processofmildheattreatmenttoreducesignificantlyorkillthenumber ofpathogenicandspoilagemicroorganisms.Thedefinitionofatraditional pasteurizationprocessreliedonlyonthermaltreatmentandisachievedby exposingfoodstoheatforacertainamountoftime.Unlikesterilization, afterpasteurizationthefoodisnotfreeofmicroorganismssinceheattreatmentisnotsevereenoughtokillheat-resistantsporesthatcansurvivethe processandmaybepresent.Thereforeadditionalformsofpreservation suchasrefrigeration(e.g.,milk),atmospheremodification(e.g.,vacuum packagingofmeatsandcheeses),additionofantimicrobialpreservatives (e.g.,sodiumchloride,sodiumnitrite,ascorbicacid,sorbicacid,andsulfur dioxide),orcombinationsofthesetechniques,arerequiredforproduct stabilizationduringdistribution.
Sinceintroducingpreservationprinciplesinfoodprocessingatthestart ofthe19thcentury,thefoodindustryandscientificcommunityhave accumulatedcriticalknowledgefortheestablishmentandvalidationof thermalandothertraditionalprocessesthatincludes:
1. Establishedorganismofpublichealthconcernfordifferentgroupsof productssuchaslow-acidproducts,milk,andjuices;
2. Wellunderstoodandknownkineticsofmicrobialdestructionandits parametersofthermalresistance(z),decimalreductiontime(DT),and lethality;
3. Knowledgeofproductheatingandheattransferingivenprocessing systems;
4. Establishingofequivalentsafetyofdifferentprocessingsystems expressedin “lethality” terms.
Processvalidationisnecessarytogiveanassurancethatcommercial sterility,pasteurization,orotherrelatedfoodsafetyobjectives(FSOs)that havebeenachievedintestconditionsalsowillbedeliveredinallsubsequentproductionconditions.Historically,therearetwoapproachestothe validationofthermalprocesses.
1. Thefirstapproachhasbeentousedirectmicrobialkillmeasurements involvinginoculationstudieswithsporeorbacterialcellsuspensions withknownheatdestruction/resistancecharacteristicsorothermicrobialchallengetests.
2. Thesecondapproachinvolvesthecollectionandrecordingoftime andtemperaturedatahistoryinthetestedproductusingspecialized data-loggingsystems,andmorerecentlyin-processdata-loggingwith smalldataloggersthatcanpassthroughthecontinuousprocess,and collectdataforsubsequentanalysisandinterpretation.
Inbothcasessomeformofmathematicalmodelinghasbeenusedto interpretthedatainthecontextofFSOsand/orcommercialsterility.The mathematicalmodelsforinterpretationofthedataaredesignedtoreflect theappropriatedeathkineticsofthetargetmarkerorganisms. Mathematicalmodelssuchastheapplicationof D and z valuesinthe developmentofthermalprocessinghaveprovenextremelyuseful.The modelsalsoprovideawayofintegratingtheoveralllethaleffectofthe thermalprocess,enablingprocessesofdifferenttimesandtemperaturehistorytobecomparedonacommonbasisoflethalityequivalence. Lethalityisanessentialelementofprocessestablishmentandvalidation thathasbeendevelopedforthermallyprocessedfoods.Itprovidesthe abilitytoexpressprocessdeliveryintermsofunitsoflethalityandto understandtheequivalentsafetyofdifferentprocessingsystems.Byincorporatingboththekineticsofthedestructionoftheorganismofpublic healthconcernandthemathematicalmodelingofheatingcurvesthethermalprocessingindustrydevelopedthetermsofprocessvaluessuchas “sterilizationvalue” (FT)andpasteurizationvalue(PT).Whenthesterilizationvalue(FT)hasareferencetemperatureof121.1°Citiscalledan Fo, andpasteurizationvalue(PT)withareferencetemperatureof72°Cis called Po.Thesterilizationandpasteurizationvaluesarethemeasurement ofthenumberofminutesthatwouldresultinthesameeffectivenessof theprocessiftheproducthadbeenheldat121.1°Cor72°C/90°C, respectively.A “worstcase” approachbychoosingsamplesthatreceived thelowesttime temperaturetreatmenttoestablishasafeprocessistraditionallyusedinthermalprocessing.Thisapproachaimingatgivinga greaterassuranceofprocesssafetyoftenresultsinavastmajorityofoverprocessedproductsandleadstolowerqualityasaresult.
Theabilitytounderstandtheequivalentefficacyofthermalprocesses isimportantwhenitcomestocommercialapplicationsandcompliance withassociatedinternationalregulatoryrequirements.Also,itisevident thatthevalidationtemplatedevelopedovermanyyearsforactivitiessuch ascanning,andasepticapplicationscouldserveasa “blueprint” forother applicationsofnovelprocessingtechnologies.
1.2Establishmentofthepreservationprocess
Thecriticalproduct,process,andstorageconditiondifferencesbetween targetmicroorganismsthataretobeconsideredtoestablishpasteurization orsterilizationpreservationspecificationsaresummarizedin Table1.1.
Table1.1 Criticalproduct,process,andstorageconditionsfortheestablishmentofpreservationspecifications.
PasteurizationSterilization
Productparameters
pH , 3.53.5 , pH , 4.6pH . 4.6pH . 4.6
Aw . 0.86
Processparameters
Temperature,°C65 72 . 65 . 65 . 121
Additional hurdles NoRefrigerationAntimicrobials, Aw
Targetmicroorganisms
Pathogenic
SpoilageMolds,yeastsLacticbacteria,yeasts, molds
Geobacillus spp. Bacilluscereus
StorageAmbientRefrigeratedconditionsAmbienttemperature
PackagingHermeticallysealedflexiblecontainersHermeticallysealedflexible containers
Ageneralapproachtotheestablishmentofprocessingtechnologies includes:
1. Identificationoftheorganismofconcernofpublichealthsignificance;
2. Identificationandselectionoftheappropriatetargetend-pointor microbialreduction;
3. Developmentofaconservativeestimationoftheabilityoftheprocess toconsistentlydeliverthetargetend-pointorspecificlogreduction;
4. Quantitativevalidation(microbiologicalormathematically)ofthe lethaltreatmentdelivered;
5. Listofthecriticalfactorsandproceduresusedtocontrolthedelivery oftherequiredprocess.
Forthedesignofa “preservationspecification” tomeetrequiredspecificlogarithmicmicrobialreduction(SLR)innumbersoftargetmicroorganisms,processingtime Fp ortargetprocessvalueistraditionallydefined bytheinitialloadoftargetorganisms(No),theend-pointoftheprocess (NF),andthelogarithmicresistanceoftargetbacteriaunderdefinedconditions(DT)asgivenin Eq.(1).
5 DT ðlogNo logNF Þ 5 ðSLRÞ xDT (1)
where DT isadecimalreductiontime(min)atthereferencetemperature ofathermalprocess.
Databasescontainingkineticinactivationparametersforvarioustarget pathogenicandspoilagemicroorganismsareneededfortheestablishment ofprocessingtimeandcriticalpreservationprocessparameters.
Eq.(2)estimatestheaccumulatedlethality F,sterilization(F0),orpasteurizationvalue(P0)ofathermalprocess,whenthereferencetemperatureand z valuesaredefinedforspecificmicroorganismsandproducts
where T (°C)isatemperatureand t istime(min). Tref isareferencetemperatureofthethermalprocess. Z isbacterialcellsorthespore’sthermal resistance(°C)atthereferencetemperature.
Thevalidationoftheprocessingtimeunderactualproductionconditionsrequirestheaccumulationofaminimumprocessvalueunderworst caseconditions(cold-spot,lowprocesstemperature,etc.)of Fo.Themeasuredoractualtreatmenttime Fp undersimilarworstcaseconditionsthat isrequiredtoachieveatargetSLRshouldmeetthecondition(3)thatis:
. Fp (3)
Fp
Theprocedureofestablishingaprocessandthenvalidatingitseffectivenessisdependentontheprocessingsystemusedandthefoodproduct beingproduced.However,allassumptionsassociatedwithhistorical experimentalprocedureswillneedtobeverifiedfortheirapplicabilityto thenewapplication.Theprocessorneedstomakesurethatasufficiently verifiedapproachisusedtocollecttheneededinformationnecessaryto understandtheprocessdeliveredandifthetargetend-pointwasachieved.
Theconclusionsandrecommendationsthatexistfortheestablishment andvalidationofthermalpasteurizationandsterilizationtreatmentcanbe modifiedandadoptedfornovelthermalornonthermalprocesses.Itwill benecessarytodeterminemicrobialinactivationkineticsandrateconstantsthataresimilarto D-and z valuesandintegratedprocesslethalityto determineprocessequivalency.
2.Nonthermaltechnologiesandchallengesofvalidationof novelprocessescomparedtothermalprocessing
2.1Reviewoffundamentalprinciples
Overthelastfewdecades,thefifth “alternative” processingconceptcalled “novelprocessingtechnologies” startedtoemergegloballyinfoodproduction.Inthehistoryoftechnologydevelopment,noveloremerging technologiesarethosecontemporarytechnicalinnovationswhichrepresentprogressivedevelopmentswithinafieldforacompetitiveadvantage. Inthefoodindustry,asaresultofmoderndemandsforfoodsthatare fresher,healthier,morenatural,orminimallyprocessedandadditive-free, novelprocessingtechniquesarecurrentlyunderbroaddevelopmentand implementation.Theuseofnoveltechnologiesultimatelybringsthe advantageoftheproductionoffoodswithbetterqualityandhighernutrientcontentsduetoreducedthermalandchemicalabuse,superiorsafety attributesduringextendedshelf-life,andatareasonablecostfortheconsumer.Foodsafetyisoneoftheessentialcomponentsthatdrivesthe developmentofnoveltechnologiessuchasphysicalmicrobialintervention toreduce,control,oreliminatefoodbornepathogensfromfoodproducts andcontactsurfaces.Additionally,novelprocessingtechnologieshave potentialtobeusedastoolstotailorfoodswithbetterquality,addedor enhancedfunctionalandnutritionalvalues,tolowerthecarbonfootprint, andsubstantiallyreducewatervolumesusedinheattransferprocesses.As anexample,novelprocessingmethodsarebeingexploredtopotentially
createhypoallergenicproducts,andhavebeentestedtoaltertheallergen reactivityofcomponentsoffoodmatrices.
Thisfifth “novel” processingconceptincludesadvancedthermaland nonthermalhigh-technologymethodsbasedontheutilizationofmechanical,electrical,andelectromagneticenergy,andcombinedapplications approaches.So-callednovelfoodswithnohistoryofconsumptionthat maybeproducedbynovelprocesseshavestartedtoemergeinthemarket andoftencanreplacetraditionalstylefoods.Forexample,old-styleham treatedbyhighhydrostaticpressure(HHP)orfreshappleciderpasteurized usingultraviolet(UV)lightforbetterproductsafetyaredescribedasnovel foods.
Food-processingtechniquesthatcanbeusedforthereductionof microbialloadsincluderemovalandinactivationapproaches.Known removalunitoperationsincludefiltration,centrifugation,andseparation, whichbelongtothegroupofhydrodynamicprocessesthataredrivenby ahydrostaticorhydrodynamicpressuregradient.Unitoperationsthatare usingmicrobialinactivationincludeanumberofphysicalmethodsand chemicalagentscapableofpronouncedbactericidaland/orsporicidal effects.Asummaryofdifferenttechniquesthathavebeenexploredand theirfundamentalprinciplestodeliveralethalmicrobialtreatmentispresentedin Table1.2
Therearetypicallynumerousunknownsassociatedwiththesafeuse ofnovelpreservationtechnologiesintheproductionoffoodsandbeveragesintendedforhumanconsumption.Duetodifferentfundamental principlesandperformancecapabilitiesofnoveltechnologies,novelprocessesdifferfromtraditionalthermalprocessingintermsofthetypesof foodcategoriesthatcanbetreated,microbialefficacyandmicrobial destructionmodes,desiredandundesiredeffectsonfoodcompositionand quality,andtheireconomicandenvironmentalimpacts.Additionally,the fullcommercializationandproductionpotentialofnovelthermaland nonthermaltechnologiesandfood-processingoperationsbasedontheir useisnotbeingrealizedduetoalackofinformedandendorsedguidance regardinghowtoimplementthepropertechnologyvalidationanddemonstrateitssafety.Beforeanovelprocesscanbeusedandtheresulting productcanbesold,thoroughreviewsoftheimpactoncomposition, quality,andnutrition,andevaluationsofthesafetyofthenovelprocess andconsequentlynovelfoodshavetobeconductedbyfoodindustryprofessionalsandregulatoryagencies.Asaresult,theincrementaldevelopmentsofnoveltechnologiesforavarietyoffoodapplicationshaveledto
Table1.2 Food-processingunitoperationsandfundamentalprinciplesoftraditionalandnovelprocessingtechnologies.
Microbialreduction principle
PhysicalmechanismofactionDrivingforceProcessAdditionalbactericidal modes
RemovalMomentumtransferPressuredifferenceFiltration
Separation
Centrifugation
ThermalinactivationHeattransferTemperaturedifferenceBlanching
Drying
Heatpasteurization
Heatsterilization
ElectromagneticenergyTemperaturedifferenceInfraredheating
Microwaveheating(MWH)
Radiofrequency
ElectricalenergyTemperaturedifferenceOhmicheating
Conductionheating
Momentumtransferandheat generation TemperaturedifferencePressure-assistedthermal sterilization
Pressureand compressionheating
Momentumtransferandheat generation TemperatureUltrasonicationCavitation
Localtemperature increase
Nonthermal inactivation
ElectromagneticenergyChargedparticles
Electronstransfer
UVlightphotontransfer
Irradiation
Electronbeams
UVenergy
SupercriticalfluidconditionsConcentrationPressureandCO2
MomentumtransferHydrodynamicpressurein liquids
Temperatureincrease
MomentumtransferHydrodynamicpressurewaves insolids
Freeradicals
Highpenetrating power
PressurehomogenizationTemperature Cavitation
Highhydrodynamicpressure/ shockwaves
Shearstress
MomentumtransferHydrostaticpressureinliquids andsolids HHP (Continued)
Table1.2 (Continued)
Microbialreduction principle PhysicalmechanismofactionDrivingforceProcessAdditionalbactericidal modes
PulsedenergyElectricalfieldsHighvoltagegradientPulsedelectricfields(PEFs)Temperature
ElectromagneticenergyLightandUVphotonstransferPulsedlightTemperature
MomentumtransferPressurePressurecycling
PlasmaElectricalorelectromagnetic energy Chargedparticlesandphoton transfer AtmosphericplasmaLightphotons Freeradicals
Chargedparticles
ChemicalOxidationConcentrationOzone
Carbondioxide
Ionexchange
Chlorination pHadjustment
OsmoticpressureSoluteconcentrationWateractivityBoundwater
