Table Of Content

Microwave and Radio Frequency Heating in Food and Beverages This page intentionally left blank Microwave and Radio Frequency Heating in Food and Beverages Tatiana Koutchma Research Scientist, Agriculture and Agri-Food Canada AcademicPressisanimprintofElsevier 125LondonWall,LondonEC2Y5AS,UnitedKingdom 525BStreet,Suite1650,SanDiego,CA92101,UnitedStates 50HampshireStreet,5thFloor,Cambridge,MA02139,UnitedStates TheBoulevard,LangfordLane,Kidlington,OxfordOX51GB,UnitedKingdom Copyright©2023ElsevierInc.Allrightsreserved. Nopartofthispublicationmaybereproducedortransmittedinanyformorbyany means,electronicormechanical,includingphotocopying,recording,oranyinformation storageandretrievalsystem,withoutpermissioninwritingfromthepublisher.Detailson howtoseekpermission,furtherinformationaboutthePublisher’spermissionspolicies andourarrangementswithorganizationssuchastheCopyrightClearanceCenterandthe CopyrightLicensingAgency,canbefoundatourwebsite:www.elsevier.com/permissions. Thisbookandtheindividualcontributionscontainedinitareprotectedundercopyright bythePublisher(otherthanasmaybenotedherein). Notices Knowledgeandbestpracticeinthisfieldareconstantlychanging.Asnewresearchand experiencebroadenourunderstanding,changesinresearchmethods,professional practices,ormedicaltreatmentmaybecomenecessary. Practitionersandresearchersmustalwaysrelyontheirownexperienceandknowledgein evaluatingandusinganyinformation,methods,compounds,orexperimentsdescribed herein.Inusingsuchinformationormethodstheyshouldbemindfuloftheirownsafety andthesafetyofothers,includingpartiesforwhomtheyhaveaprofessionalresponsibility. Tothefullestextentofthelaw,neitherthePublishernortheauthors,contributors,or editors,assumeanyliabilityforanyinjuryand/ordamagetopersonsorpropertyasa matterofproductsliability,negligenceorotherwise,orfromanyuseoroperationofany methods,products,instructions,orideascontainedinthematerialherein. ISBN:978-0-12-818715-9 ForinformationonallAcademicPresspublicationsvisitourwebsiteat https://www.elsevier.com/books-and-journals Publisher:NikkiP.Levy AcquisitionsEditor:NinaBandeira EditorialProjectManager:EmeraldLi ProductionProjectManager:KiruthikaGovindaraju CoverDesigner:ChristianBilbow TypesetbyTNQTechnologies Contents Introduction and Brief History of Microwave and Radio Frequency Heating CHAPTER 1 Basic principles and mechanisms of electromagnetic heating technologies for food processing operations.............................................3 1.1 Introduction.......................................................................3 1.1.1 Basic principlesof electromagnetic heating technologiesand their applications...............................3 1.1.2 Microwaveand radio frequencybands..........................8 1.1.3 Mechanisms ofmicrowaveand radio frequency heat generation........................................................11 1.1.4 Microwaveheatinginfood processing operations..........14 1.1.5 Radio frequencyheating infoodprocessing operations...............................................................23 1.2 Conclusions.....................................................................25 References.............................................................................26 Further reading.......................................................................27 CHAPTER 2 Heating characteristics of microwave systems and dielectric properties of foods...........................29 2.1 Introduction.....................................................................29 2.2 Microwavesystems andtheir heating characteristics...............29 2.2.1 Design and operation principles ofdomestic and commercial microwaveheating systems for food...........29 2.2.2 Heating characteristics ofmicrowave systems...............35 2.2.3 Effect of productgeometry........................................37 2.3 Dielectricproperties offoods.............................................38 2.3.1 Effect offoods’dielectric properties onmicrowave heating...................................................................39 2.3.2 Effect offood electricalconductivity onmicrowave heating...................................................................40 2.3.3 Effect of other physical and thermal properties onmicrowave heating...............................................40 2.4 Factors influencing dielectric properties offoods...................41 2.4.1 Temperature............................................................41 2.4.2 Moisture content......................................................41 2.4.3 Chemicalcomposition...............................................42 v vi Contents 2.4.4 Effects ofnonelectrolytesin water..............................43 2.4.5 Effect ofpHandionicstrength...................................43 2.4.6 Organic solids..........................................................43 2.4.7 Proteins..................................................................43 2.5 Propagation ofmicrowave electromagnetic waves..................44 2.5.1 Transmissionproperties offoods.................................44 2.5.2 Wave impedance and power reflection.........................45 2.5.3 Dielectric propertiesofmixtures.................................46 2.6 Dielectric properties offoods inradio frequencyrange...........49 2.7 Conclusions.....................................................................50 2.8 Nomenclature..................................................................51 References.............................................................................51 Further reading.......................................................................53 CHAPTER 3 Microwave heating effects on foodborne and spoilage microorganisms.......................................55 3.1 Introduction.....................................................................55 3.2 Kinetics ofmicrobial inactivation under microwave heating...........................................................................57 3.3 Effect of microwaveenergyonmicroorganisms.....................61 3.4 Effects offoodproperties on microbialinactivation under microwaveheating...................................................64 3.5 Effects on microwaveheatingparameterson microbial inactivation.....................................................................66 3.5.1 Microwave continuous flowsystems............................66 3.5.2 Viscous products and products with particles................69 3.6 Combined action of microwaveswith otherchemical or physical factors............................................................73 3.7 Conclusions.....................................................................74 References.............................................................................75 Further reading.......................................................................78 CHAPTER 4 Microwave heating and quality of food...................81 4.1 Introduction.....................................................................81 4.2 Microwavesheating effects on overall quality offoods...........83 4.2.1 Overallquality.........................................................84 4.2.2 Moisture content......................................................85 4.2.3 Color......................................................................85 4.2.4 Flavor....................................................................86 4.3 Microwaveheating effects on the destruction of vitamins and other nutrients in food.....................................87 4.3.1 Polyphenols.............................................................91 Contents vii 4.4 Microwaveheatingeffects on lipids,proteins, and carbohydrates infoods......................................................93 4.4.1 Edible oils and fats...................................................94 4.4.2 Proteins..................................................................95 4.4.3 Carbohydrates..........................................................96 4.4.4 Polysaccharides........................................................96 4.4.5 Starch.....................................................................97 4.4.6 Microwaveheatingfor developingfoods with low glycemic index...................................................98 4.4.7 Minerals.................................................................98 4.5 Microwavesheatingand enzymes destruction infoods............99 4.6 Effects ofmicrowaveheatingon foodchemistry..................103 4.6.1 Chemicalreactions.................................................103 4.6.2 Acrylamide formation.............................................105 4.6.3 Thiobarbituric acid values........................................106 4.7 Conclusions...................................................................107 References...........................................................................108 CHAPTER 5 Essential aspects of commercialization of applications of microwave and radio frequency heating for foods..................................................113 5.1 Introduction.................................................................113 5.2 Packagingfor microwave heating....................................114 5.2.1 Passivepackaging.................................................114 5.2.2 Activepackaging..................................................115 5.2.3 Microwavable packages.........................................116 5.3 Microwave process validation.........................................118 5.4 Temperature and process lethality measurements during microwaveheating..............................................120 5.4.1 Temperature probes..............................................120 5.4.2 Thermal imaging..................................................121 5.4.3 Process lethalityindicators.....................................121 5.5 Microwavable foods andcooking instructions....................122 5.6 Regulatory status and commercialization..........................126 5.7 Industrialmicrowave processesand systems......................127 5.7.1 Ready-to-eat meals and in-pouch sterilization...........127 5.8 Industrialradiofrequencyheatinginprocesses andsystems.130 5.9 Modeling ofmicrowaveheatingsystems..........................131 5.10 Conclusions.................................................................134 References...........................................................................134 viii Contents CHAPTER 6 Economics, energy, safety, and sustainability of microwave and radio frequency heating technologies........................................................137 6.1 Introduction...................................................................137 6.2 Costofcapitalequipment................................................140 6.2.1 Operating costs......................................................141 6.2.2 Energyefficiency andcost.......................................141 6.3 Savingsfrom processing changes......................................144 6.4 Safetyof microwaveheating............................................146 6.5 Sustainability of microwaveand radiofrequency heatingand equipment....................................................147 6.5.1 Microwave packaging sustainability..........................149 6.5.2 Domestic microwaveovens......................................149 6.5.3 Microwave-assisted technologies toachievecircular economy...............................................................150 6.5.4 Microwave-assisted extraction..................................151 6.5.5 Microwave-assisted pyrolysisoffood waste................152 6.5.6 Nextdevelopment steps...........................................154 6.6 Conclusions...................................................................154 References...........................................................................155 CHAPTER 7 Conclusions, knowledge gaps, and future prospects............................................................157 Index...................................................................................................159 Introduction and Brief History of Microwave and Radio Frequency Heating