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FoodProcessingTechnology WoodheadPublishingSeriesinFoodScience,TechnologyandNutrition
FifthEdition
P.J.Fellows
WoodheadPublishingisanimprintofElsevier
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Notices
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ISBN:978-0-323-85737-6(print)
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Dedication ForWenandMolly PartI Basicprinciples
1. Propertiesoffoodsandprinciplesof processing3
1.1Physicalproperties3
1.1.1Densityandspecificgravity3
1.1.2Viscosity10
1.1.3Surfaceactivity12
1.1.4Wateractivity13
1.2Biochemicalproperties19
1.2.1Acids,basesandpH19
1.2.2Redoxpotential21
1.3Engineeringprinciples21
1.3.1Masstransferandmassbalances22
1.3.2Fluidflow25
1.3.3Phaseandglasstransitions28
1.3.4Heattransfer31
1.3.5Typesofheatexchangers45
1.3.6Effectofheatonmicroorganisms andenzymes45
1.3.7Effectofheatonnutritionaland sensorycharacteristicsoffoods48
1.3.8Sourcesofheatandmethodsof applicationtofoods51
1.3.9Energyuseandmethodstoreduce energyconsumption53
1.4Processmonitoringandcontrol56
1.4.1Processanalyticaltechnologyand qualitybydesign57
1.4.2Sensors59
1.4.3Processcontrollers63
1.4.4Softwaredevelopmentsandthe InternetofThings66
1.4.5Neuralnetworks,fuzzylogicand robotics67
1.5Hygienicdesignandcleaningof processingfacilitiesandequipment70
1.5.1Hygienicdesign70
1.5.2Cleaningandsanitation77
1.6Waterandwastemanagement80 References82 Furtherreading94
PartII
Ambient-temperatureprocessing
2. Rawmaterialpreparation99
2.1Cleaningfoods99
2.1.1Wetcleaning100
2.1.2Drymethodsofcleaning102
2.2Sortingandgrading103
2.2.1Shapeandsizesorting104
2.2.2Weightsorting106
2.2.3Colourandmachinevision sortingandgradingsystems108
2.2.4Othertypesofgrader110
2.3Peelingandcoring110
2.3.1Coring111 References111
3. Extractionandseparationoffood components113
3.1Centrifugation113
3.1.1Theory113
3.1.2Equipment116
3.2Filtration119
3.2.1Theory119
3.2.2Equipment120
3.3Expression123
3.3.1Theory123
3.3.2Equipment124
3.4Extractionusingsolvents129
3.4.1Theory129
3.4.2Solvents129
3.4.3Equipment130
3.4.4Developmentofalternativesto organicsolvents131
3.5Membraneseparation135
3.5.1Theory136
3.5.2Equipmentandapplications139
3.5.3Typesofmembranesystems142
3.6Effectsonfoodsandmicroorganisms145
3.6.1Effectonmicroorganisms145 References146
4. Sizereduction151
4.1Sizereductionofsolidfoods151
4.1.1Theory151
4.1.2Equipment154
4.1.3Developmentsinsizereduction technology163
4.1.4Effectonfoods164
4.1.5Effectonmicroorganisms166
4.2Sizereductioninliquidfoods167
4.2.1Theory167
4.2.2Emulsifyingagentsandstabilisers167
4.2.3Equipment169
4.2.4Effectonfoods172
4.2.5Effectonmicroorganisms173 References174
5. Mixing,forming,coatingand encapsulation179
5.1Mixing179
5.1.1Theoryofsolidsmixing180
5.1.2Theoryofliquidsmixing182
5.1.3Gasmixingandblending184
5.1.4Equipment186
5.1.5Effectonfoodsandmicroorganisms194
5.2Forming195
5.2.1Breadmoulders195
5.2.2Pie,tartandbiscuitformers196
5.2.3Confectionerymouldersand depositors196
5.2.4Coldextrusion201
5.2.5Three-dimensionalfoodprinting202
5.3Coatingfoods205
5.3.1Coatingmaterials205
5.3.2Equipment207
5.3.3Microencapsulation209
5.3.4Ediblebarriercoatings214 References215
6. Foodbiotechnology223
6.1Fermentationtechnology223
6.1.1Theory224
6.1.2Equipment227
6.1.3Commercialfoodfermentations231
6.1.4Effectsonfoods231
6.2Microbialenzymes233
6.2.1Novelenzymetechnologies236
6.3Bacteriocinsandantimicrobial ingredients236
6.3.1Chitinandchitosans236
6.4Functionalfoods237
6.4.1Healthandnutritionclaimsand regulation237
6.4.2Probiotic,prebioticandsynbiotic foods238
6.5Geneticmodification239
6.5.1Geneticallymodifiedfoodcrops239
6.5.2Geneticallymodifiedmicroorganisms andtheirproducts242
6.5.3Marker-assistedselection242
6.6Nutritionalgenomics242 References243
7. Minimalprocessingmethods251
7.1Introduction251
7.1.1Hurdleconcepts251
7.2Highpressureprocessing255
7.2.1Introduction255
7.2.2Theory257
7.2.3Equipmentandoperation258
7.2.4Processdevelopments261
7.2.5Packaging261
7.2.6Effectsonfoodcomponents262
7.2.7Effectsonenzymes263
7.2.8Inactivationofmicroorganisms263
7.2.9Regulation265
7.2.10Applications265
7.3Irradiation267
7.3.1Introduction267
7.3.2Theory267
7.3.3Equipment269
7.3.4Measurementofradiationdose271
7.3.5Detectionofirradiatedfoods271
7.3.6Regulation272
7.3.7Applications272
7.3.8Effectsonfoods274
7.3.9Effectsonmicroorganisms274
7.3.10Effectsonpackaging275
7.4Ozone276
7.4.1Ozoneproductionanduse276
7.4.2Antimicrobialactivity277
7.4.3Processingapplications278
7.4.4Limitationsandpotentialtoxicity280
7.5Powerultrasound280
7.5.1Theory281
7.5.2Processingequipment282
7.5.3Effectonmicroorganisms, enzymesandfoodcomponents282
7.6PEFprocessing284
7.6.1Theory284
7.6.2Equipmentandoperation286
7.6.3Effectsonmicroorganisms, enzymesandfoodcomponents287
7.6.4ApplicationsofPEF288
7.6.5CombinationsofPEFandother treatments290
7.6.6Regulation290
7.7Pulsedlight290
7.7.1Theory290
7.7.2Equipment293
7.7.3Effectonmicroorganisms, enzymesandfoodcomponents294
7.7.4Regulationanduse295
7.8Otherminimalprocessingmethods underdevelopment295
7.8.1Dense-phasecarbondioxide295
7.8.2Electricarcdischargeprocessing andcoldplasma298
7.8.3Oscillatingmagneticfields299
7.8.4PulsedX-rays300 References301
8. Blanching317
8.1Theory317
8.2Equipment318
8.2.1Steamblanchers319
8.2.2Hot-waterblanchers322
8.2.3Newerblanchingmethods322
8.3Effectonfoods323
8.4Effectonmicroorganisms324 References325
9. Industrialcooking327
9.1Cookingusingmoistheat327
9.1.1Equipment328
9.2Sousvidecooking332
9.2.1Theory333
9.2.2Processing333
9.2.3Effectsonfoods335
9.3Cookingusingdryheat337
9.3.1Equipment338 References340
10. Pasteurisation343
10.1Theory343
10.2Equipment347
10.2.1Pasteurisationofpackagedfoods347
10.2.2Pasteurisationofunpackaged liquids348
10.2.3Novelpasteurisationmethods352 10.3Effectsonfoods354 References354
11. Heatsterilisation357
11.1In-containersterilisation357 11.1.1Theory357 11.1.2Retorting368 11.1.3Equipment369 11.2Ultrahightemperature/aseptic processes371 11.2.1Theory372
11.2.2Processing374 11.2.3Equipment375 11.3Effectsonfoods379 11.3.1Canning379 11.3.2UHTprocessing380 References383
12. Evaporationanddistillation389
12.1Evaporation389 12.1.1Theory389 12.1.2Improvingtheeconomicsof evaporation393 12.1.3Equipment397 12.1.4Effectonfoodsand microorganisms404 12.2Distillation404 12.2.1Theory404 12.2.2Equipment410 12.2.3Effectsonfoodsand microorganisms411 References411
13. Dehydration415
13.1Theory415
13.1.1Dryingusingheatedair415
13.1.2Dryingusingheatedsurfaces424
13.2Equipment425
13.2.1Hot-airdryers425
13.2.2Heated-surface(orcontact) dryers440
13.3Controlofdryers442
13.4Typesofpowders443
13.4.1Agglomeration444
13.5Rehydration445
13.6Effectsonfoodsandmicroorganisms445
13.6.1Sensoryproperties445
13.6.2Nutritionalvalue448
13.6.3Effectsonmicroorganisms449 References449
14. Smoking455
14.1Theory456
14.1.1Constituentsinsmoke456
14.1.2Tastelesssmoke459
14.1.3Liquidsmoke459
14.2Processing460
14.2.1Equipment461
14.3Effectsonfoods461
14.3.1Organolepticquality461
14.3.2Nutritionalvalue462
14.3.3Healthconcerns462
14.4Effectsonmicroorganisms462 References463
15. Bakingandroasting467
15.1Theory467
15.2Equipment469
15.2.1Directandindirectheating469
15.2.2Energy-savingfeatures471
15.2.3Batchandsemicontinuousovens471
15.2.4Continuousovens472
15.2.5Controlofovens474
15.3Effectsonfoodsandmicroorganisms474
15.3.1Changestosensory characteristics475
15.3.2Changestonutritionalvalue477
15.3.3Effectsonmicroorganisms477 References479
16. Extrusioncooking483
16.1Theory484
16.1.1Propertiesofingredients484
16.1.2Extruder-operatingcharacteristics487 16.2Equipment489
16.2.1Single-screwextruders490
16.2.2Twin-screwextruders491 16.2.3Controlofextruders492 16.3Applications494 16.3.1Confectioneryproducts494 16.3.2Cerealproducts494 16.3.3Protein-basedfoods496 16.4Effectonfoodsandmicroorganisms499 16.4.1Sensorycharacteristics499 16.4.2Nutritionalvalue499 16.4.3Effectsonmicroorganisms500 References500
17. Frying505
17.1Theory505 17.1.1Heatandmasstransfer505 17.1.2Typesofoilsusedforfrying509 17.1.3Oilabsorption511 17.2Equipment513 17.2.1Atmosphericfryers513 17.2.2Vacuumandpressurefryers515 17.2.3Controloffryeroperation, oilfiltrationandheatrecovery516 17.3Effectsoffryingonoils517 17.4Effectsoffryingonfoods518 17.4.1Changestofoodtexture, colourandflavour518 17.4.2Nutritionalchangesandhealth concerns518 17.5Effectsoffryingonmicroorganisms519 References520
18. Dielectric,ohmicandinfrared heating523
18.1Dielectricheating524 18.1.1Theory524 18.1.2Equipment528 18.1.3Applications532 18.1.4Effectsonfoodsand microorganisms535 18.2Ohmicheating536 18.2.1Theory537 18.2.2Equipmentandapplications539 18.2.3Effectsonfoodsand microorganisms541 18.3Infraredheating541 18.3.1Theory541 18.3.2Equipmentandapplications541 18.3.3Effectsonfoodsand microorganisms542 References542
19. Heatremovalbyrefrigeration551
19.1Theory551
19.1.1Refrigerantsandcryogens551
19.1.2Therefrigerationcycle558
19.1.3Magneticrefrigeration561
19.2Equipment562
19.2.1Controlofmechanical refrigerators563
19.2.2Temperaturemonitoring563 References564
20. Coolingandchilling567
20.1Coolingcropsandcarcasses567
20.1.1Theory567
20.1.2Equipment573
20.2Chilling575
20.2.1Equipment576
20.2.2Chillingofprocessedfoods578
20.2.3Cook chillsystems579
20.2.4Effectsonsensoryandnutritional qualitiesoffoods580
20.2.5Effectsonmicroorganisms580
20.3Coldstorage581 References581
21. Freezing585
21.1Theory585
21.1.1Icecrystalformation586
21.1.2Soluteconcentration588
21.1.3Calculationoffreezingtime589
21.1.4Thawing593
21.2Equipment594
21.2.1Mechanicalfreezers595
21.2.2Cryogenicfreezers599
21.2.3Developmentsinfreezing technologies601
21.2.4Frozenstorage604
21.2.5Thawing604
21.3Effectsonfoods606
21.3.1Freezing606
21.3.2Frozenstorage608
21.3.3Thawing611
21.4Effectsonmicroorganisms612 References612
22. Freezedryingandfreeze concentration619
22.1Freezedrying619
22.1.1Theory619
22.1.2Equipment623
22.1.3Effectsonfoodsand microorganisms625
22.2Freezeconcentration626
22.2.1Theory626
22.2.2Equipment627
22.2.3Effectsonfoodsand microorganisms628 References629
23. Packaging633
23.1Theory634
23.1.1Factorsaffectingtheselection ofapackagingmaterial636
23.1.2Interactionsbetween packagingandfoods642
23.2Typesofpackagingmaterials643
23.2.1Textilesandwood643
23.2.2Metal643
23.2.3Glass647
23.2.4Flexiblefilms649
23.2.5Rigidandsemirigidplastic containers656
23.2.6Paperandboard658
23.2.7Combinedpackagingsystems663
23.3Packagingmaterialsformodified atmospherepackaging663
23.3.1Effectonmicroorganisms668
23.4Printing669
23.4.1Barcodesandothermarkings670
23.5Packagingdevelopments673
23.5.1Edibleandbiodegradable materials673
23.5.2Nanotechnology677
23.5.3Activeandintelligent packaging678
23.6Environmentalandregulatory considerations688
23.6.1Environmentalissues688
23.6.2Regulatoryaspects694 References695
24. Fillingandsealingofcontainers711
24.1Rigidandsemirigidcontainers712
24.1.1Filling712
24.1.2Sealing716
24.2Flexiblecontainers723
24.2.1Form-fill-sealequipment725
24.2.2Tray,potandcartonsealing729
24.3Twist-wrapping729
24.4Shrink-wrappingandstretch-wrapping729
24.5Tamper-evidentandtamper-resistant closures730
24.6Labelling730
24.7Checkweighing732
24.8Metaldetection732
24.8.1Detectingothercontaminants733 References734
Furtherreading737
25. Materialshandling,storageand distribution739
25.1Materialshandling739
25.1.1Solidshandlingmethods740
25.1.2Liquidhandlingmethods743
25.2Storage744
25.2.1Ambientstorage744
25.2.2Distributionwarehousing745
25.2.3Modifiedandcontrolled atmospherestorage746 References749
Furtherreading751
Glossary,acronymsandsymbols753 Index765
Aboutthebook Foodprocessingisamultidisciplinarysubjectthatincludeschemistry,biochemistry,physics,biology,microbiology, sensoryanalysis,engineering,marketing,economics,managementandpsychology.Thisbookfocusesmainlyonthe technicalconsiderationsofprocessing,includingthetheory,equipmentandapplicationsofeachunitoperation.The bookaimstointroducestudentsoffoodscienceandtechnologyorbiotechnologytothewiderangeoftechniquesthat areusedtoprocessfoods.Itshowshowknowledgeofthepropertiesoffoodsandtherequiredchangestothemareused todesignequipmentandtocontrolprocessingconditionsatacommercialscaleofoperation.Theaimisalwaysto makeproductsthatareattractive,saleable,safeandnutritious,withtherequiredshelflife.
Itisacomprehensiveyetbasictext,offeringanoverviewofmostunitoperations(Fig.1),writteninstraightforward language,withexplanationsofscientifictermsandconceptsandtheminimumuseofjargon.Itprovidesdetailsofthe processingmethodsandequipment,operatingconditionsandtheeffectsofprocessingonbothmicroorganismsthatcontaminatefoodsandthephysicochemicalpropertiesandnutritionalqualityoffoods.Itcollatesandsynthesizesinformationfromawiderangeofsources,combiningfoodprocessingtheoryandcalculationsandresultsofscientificstudies, withdescriptionsofcommercialpractice.
Whereappropriate,referenceismadetorelatedtopicsinnutrition,technologiesthatsupportbusinessoperations, qualityassurance,HACCP,marketingandmanagementofproductionandlogistics.
Energy source
Microbial inhibition/ destruction by:
Types of unit operations Fuel (gas, petroleum based liquid fuels, solid fuels)
Blanching (8)
Renewable sources (solar (photovoltaic), wind, wave, hydro)
Solar (heating)
Steam/ hot water
Evaporation and distillation (12)
Dehydration (13)
Baking (15)
Extrusion (16)
Frying (17)
Pasteurisation (10)
Sterilisation/UHT (11)
Moisture removal Smoking (14)
Sugar preserves, salting
Chemicals
Heat
Nuclear energy (radioactive isotope decay)
Temperature reduction
Direct electrical energy
Pressure, light, sound Gamma rays, Xrays
Freeze drying/ freeze concentration (22)
Chilling (20) Freezing (21)
Fermentation/ bacteriocins (6)
Centrifugation/ filtration/ membrane separation (3)
PEF/ Electric arc (7)
Dielectric/Ohmic (18)
PEF = Pulsed Electric Field, HPP = High Pressure Processing, IR = Infrared, UHT = Ultra-High Temperature, UV = Ultraviolet
FIGURE1 Typesofprocessingandtheirpreservativeeffects(numbersinparenthesisindicatechapternumbers).
HPP (7)
Irradiation (7)
IR/pulsed light/ UV, ultrasound (7)
Thebookisdividedintofiveparts:
PartI:Importantbasicconcepts,includingengineeringprinciplesofheattransferandfluidflow,physicalandbiochemicalpropertiesoffoods,processmonitoringandcontrol,hygienicdesignandcleaningofprocessingfacilities andequipment;
PartII:Operationsthattakeplaceatornearambienttemperatureorinvolveminimalheatingoffoods;
PartIII:Operationsthatheatfoodstopreservethemortoaltertheireatingquality;
PartIV:Operationsthatremoveheatfromfoodstoextendtheirshelflifewithminimalchangestonutritionalqualityorsensorycharacteristicsand
PartV:Postprocessingoperations,includingpackaging,storage,materialshandlinganddistributionlogistics.
Ineachchapter,thetheoreticalbasisofaunitoperationisfirstdescribed.Formulaerequiredforcalculationofprocessingparametersandsampleproblemsaregivenwhereappropriate,andsourcesofmoredetailedinformationare indicated.Thebookdescribeseachtopicinawaythatisaccessiblewithoutanadvancedmathematicalbackground. Detailsoftheequipmentusedforcommercialfoodproductionanddevelopmentsintechnologyaredescribed,with videolinkstoprocessesandequipmentoperation.Finally,theeffectsofeachunitoperationonsensorycharacteristics andnutritionalpropertiesofselectedfoodsandtheeffectsoncontaminatingmicroorganismsaredescribed.
Keyfeatures:
● Comprehensive:Offeringreadersa‘one-stop’,comprehensiveresourcetoaccessawealthofinformationonmost typesoffoodprocessing.
● Clearlystructuredandorganized,withexamplesandillustrationsofapplicationsforeachprocessingtechnology.
● Cross-referencesallowreaderstoeasilynavigatethebook.
● Multimediafeatures:Hyperlinkedreferencesandvideosofequipmentandprocesses.
● Theidealresourceforstudents,researchersandprofessionalstofindrelevantinformationonprocessingoperations quicklyandeasily.
Thebookissuitableforundergraduateandpostgraduatestudentsstudyingfoodtechnology,foodengineering,food science,biotechnologyorbioprocessing,andasanadditionalperspectiveontheirsubjectareasforstudentsstudying nutrition,consumerscience,hospitalitymanagement/catering,engineeringoragriculturalsciences.
Thisfiftheditionhasbeensubstantiallyupdated,rewrittenandextended,withnewvideolinkstomanyprocesses andtheoperationofequipment.Nearlyallunitoperationshaveundergonedevelopmentssincethefourtheditionwas published,andthesearereflectedintheadditionalmaterialsineachchapter.Therearealsonewsectionson:
● gasmixingandblending;
● 3Dfoodprinting;
● electrohydrodynamicdrying;
● heatpumpdehumidifierdrying;
● bioplasticpackaging,nanoplasticpollutionandotherenvironmentalissuesconcerningpackaging;
● self-heatingandself-coolingcontainers;
● developmentsinprocesscontrolusingtheInternetofThings;
● extractionoffoodcomponentsassistedbymicrowaves,ultrasound,pulsedelectricfieldsandhighpressure;
● low-temperatureshort-timepasteurisation;
● aqueousenzymeextraction;
● nano-andmicro-encapsulation;
● culturedmeatandplant-basedmeatanalogues;
● densephaseCO2 processingincombinationwithotherminimalprocessingtechnologies;
● thawingassistedbyultrasound,highvoltageandpulsedelectricfields,highpressures,radiofrequencyandohmic heating;
● ediblebarriercoatingsand
● biosensors,spectroscopicsensorsandothernondestructive,noncontactmethodsofqualitymanagement.
Therevisededitionhasmorethan2900referencesand460photographs,diagramsandtables.
Readership:Undergraduateandpostgraduatestudentsinfoodtechnology,foodscience,biotechnologyandbioprocessing,foodengineering,foodmarketinganddistribution,consumerscience,agriculturesciencesandengineering, nutritionandhospitalitymanagement/catering.
DrPeterFellowsisaseniorconsultantinfoodprocessing,havingworkedmostlyinAfricaandAsia.Overmore than45years,hehasworkedextensivelyasafoodtechnologistinover20countries,supportinginstitutionsthatpromotesmall-scaleagro-industrialdevelopmentandidentifyingopportunitiesforpostharvestprocessingandagroenterprisedevelopment.Hisworkincludedpreparationofinformationresources,designoftrainingcourses,programme managementandprojectevaluation.Heprovidedsupportforthelocalproductionofready-to-usetherapeuticfoodsin AfricaandAsiatotreatchildrensufferingfromsevere-acutemalnutrition,andhehasheldtheUNESCOChairin PostharvestTechnologyatMakerereUniversity,Uganda.Beforehisconsultancywork,hewastheheadofagroprocessingattheinternationaldevelopmentagency,PracticalAction(previouslytheIntermediateTechnologyDevelopment Group),wherehemanagedfoodprocessingprogrammespredominantlyinSouthAsia.Priortothis,hewasaseniorlecturerinfoodtechnologyatOxfordBrookesUniversity.HegraduatedfromtheUniversityofReading(NationalCollege ofFoodTechnology)and,afterspending2yearsinNigeriamanagingaweaningfoodproductionproject,hereturned toReadingUniversitytocompletehisPhD,studyingthesymbioticgrowthofedibleyeastsonfruitprocessingwastes. Inadditiontothepreviousfoureditionsof FoodProcessingTechnology,hehaswritten33otherbookspublishedby theFoodandAgricultureOrganisationoftheUnitedNations,theUnitedNationsIndustrialDevelopmentOrganisation, PracticalActionPublications,theInternationalLabourOrganisationoftheUnitedNationsandtheTechnicalCentrefor AgriculturalandRuralCooperationACP-EU(CTA).Hehasbeenaneditorofthejournal FoodChain,publishedby PracticalActionandhaswrittenmorethan50papersandarticlesondifferentaspectsoffoodprocessing.Hehaslived inruralDerbyshireintheUnitedKingdomfornearly30yearsandisactiveinresearchinglocalhistory,helpingtopublishthreebooksonthehistoryofhisvillageandcoeditingthevillagenewsletter.Heisapart-ownerofasharednarrowboatandaneditorofthemagazine,NABONews,fortheNationalAssociationofBoatOwners.
Acknowledgements Iamindebtedtothelargenumberofpeoplewhohavegivenfreelyoftheirtime,expertiseandexperience,providedme withinformation,checkedthetextandgivenmesupportduringthislatestrevisionof FoodProcessingTechnology.My thankstoIvyDawnTorre,EditorialProjectManageratElsevier,forheradministrativesupport.Myparticularthanks alsotothepeopleinmanycompanieswhorespondedpositivelytomyrequestsforinformationabouttheirequipment andproducts;someofwhomwentoutoftheirwaytosharetheirdetailedspecialistknowledge.Finally,butnotleast, myspecialthankstoWenforherconstructivesupport,encouragementandforbearanceatmyhoursinfrontofacomputerscreenovermanymonthsduringthelockdownscausedbytheCovid-19pandemic.
Introduction Thefoodindustrytodaywouldbeunrecognizabletopeopleeventwogenerationsago.Thepaceatwhichscientific knowledgeandtechnologicaldevelopmentshasbeenappliedtofoodprocessingcontinuestoaccelerate,andthousands ofnewproductsandprocessesarebeingdevelopedandcommercialisedeveryyear.Theaimofthisfiftheditionof FoodProcessingTechnology istobringreadersuptodatewiththecurrentstatusoftheprocessesusedbythefood industryandthosethatmayshortlybecommercialized.Ahighlyselectivesummaryofimportanthistoricaldevelopmentsinfoodprocessing(Fig.1)helpstoplacethecurrentstatusincontext.
Theaimsofthefoodindustrytoday,asinthepast,arefourfold:
1. Toextendtheperiodduringwhichafoodremainswholesome(theshelflife)bypreservationtechniquesthatinhibit microbiologicalorbiochemicalchangesandallowtimefordistribution,salesandhomestorage.
2. Toincreasevarietyinthedietbyprovidingarangeoftastes,colours,aromas,shapesandtexturesinfoods.
3. Toprovidefoodsthatgivethenutrientsrequiredforhealth.
4. Togenerateincomeforthemanufacturingcompanyandprofitsforitsownersorshareholders.
Thefocusofthisbookisthefirsttwoaims.Thetechnicalconsiderationsincludethepropertiesoffoodsandprocessingconditions,whichaffectchangesthattakeplaceduringprocessingandstorage.Theyalsoincludequalityand safetymanagement,engineeringandtheselectionofequipment,scaleofoperationanddesignandconstructionofprocessingfacilities.Otherchangestofoods,causedbymicrobialspoilageorfoodsbecomingunsafe,aswellasintentional changestoaltertheeatingqualityand/ornutritionalvalueoffoods,arealsoincludedineachchapter.
Asexamplesofthedifferentaimsofprocessing,freezingisintendedtopreservetheorganolepticandnutritional qualitiesoffoodsascloselyaspossibletothefreshproduct,butwithashelflifeofseveralmonthsinsteadofafew daysorweeks.Incontrastthemainaimintheproductionofsugarconfectionery,bakeryproductsandsnackfoodsisto provideavarietyofspecificorganolepticqualitiesandaddvaluetobasicrawmaterials.
Therearealsonowglobalconsiderationstotakeintoaccount.Theseinclude:
● energyconsumption,resourceuseandsustainabilityofprocessing;
● environmentalissues(e.g.greenhousegasemissionsandglobalheating,plasticspollution);
● rawmaterialsources,includinglossofbiodiversity,ecosystemdegradationanddeforestationduetocropproduction, overfishing,animalhusbandryandwelfare;
● valuechainsandinternationalmanufacturingoperations,includingtheenvironmentalimpactofinternationaltransportationofrawmaterialsandprocessedfoodsand
● ethicalconsiderations,suchasemploymentandworkingconditionsinsuppliers’factoriesandfarms.
Theseconsiderationsarereferredtowheretheyaredirectlyrelevanttoparticularaspectsofprocessing(e.g.preventingozonedepletionbyrefrigerants,technologiesthatreduceenergyconsumption,orhealtheffectsofmicro-andnanoplasticscausedbydegradationofplasticpackagingmaterials).Similarly,businessconsiderationsinthefourthaimare onlyreferredtowheretheyhavespecificrelevance(e.g.food-relatedregulations,theroleofpackaginginmarketing andadvertising).
1Stagesinfoodprocessing Thereareusuallysixgeneralstagesinanyfoodprocess:(1)rawmaterialpreparation;(2)mixingingredients;(3)processing;(4)packaging;(5)storageand(6)distribution.Allfoodprocessinginvolvesacombinationofproceduresto achievetheintendedchangestotherawmaterials.Theseareknownas‘unitoperations’(Table1),andeachhasaspecific,identifiableandpredictableeffectonafood.Itisthecombinationandsequenceofunitoperationsateachstage thatdeterminesthenatureandqualityofthefinalproduct(Fig.2).
100 000
c. 200 000 years ago
First food processing in hunter-gatherer societies in Africa using heat from open fires to roast and smoke meats, roots and vegetables. This made foods more palatable and killed parasites and bacteria, which helped people to stay healthier.
Evidence of bread making from starch grains of cattail and fern roots, found on mortars and pestles in today’s Italy, Czech Republic and Russia. This nutrient-dense portable food was more resistant to spoilage and assisted nomadic peoples to travel.
7000 4000
Milk fat in perforated ceramic containers found in Poland indicates they were strainers to make cheese, which kept for much longer than milk without spoiling.
Mesopotamians first used vinegar to store vegetables out of season. Egyptians preserved fish and poultry meat by sun drying. Salted pork produced in China. Salt made from dried seaweed used to preserve foods and soybeansprocessed to soy sauce and miso (soy paste) to flavour foodsin Japan.
c. 2000 years ago
Sugar made from cane in the Indus Valley, India. All of the main food plants used today were cultivated somewhere in the world.
Vandals introduced butter to Europe. Mechanical equipment using water, wind and animal power developed to reduce time and labour in milling cereals, crushing olives for oil in Mediterranean countries and crushing apples for cider in Northern Europe.
European merchants established spice trade with the Orient. Specialised trades evolved, including millers, bakers, cheese-makers, brewers and distillers, each with their own distinctive local varieties of foods.
c. 200 years ago
First patent for a tin-plated steel container issued in Britain.
A can-making machine developed in USA enabled two unskilled workers to make 1500 cans per day, compared to 120 cans per day made by two skilled tinsmiths. First mechanical refrigerator using liquid ammonia invented in France. French chemist and microbiologist, Louis Pasteur, developed the pasteurisation process. First successful refrigerant compressor developed in Sweden. Pressure-cooking retort using steam invented.
Domesday Book lists nearly 6000 water- and wind-powered flour mills in England, one for every 400 inhabitants.
Knights returning to Europe from 2nd Crusade brought sugar from Middle East. Marco Polo returned to Venice with noodles from China. Mongols spread technologies to Central Asia and Eastern Europe to make kumiss (fermented mare’s milk), dried cheese and ales made from fermented millet.
Portuguese brought cloves from East Indies for use in preserves and sauces and introduced chilli peppers and cayenne from Latin America to India. Spanish conquistadors returned from South America with avocado, papaya, tomato, vanilla, kidney beans and potatoes.
African slaves were sold to sugar planters in the Caribbean and Latin America.
Income from sales of sugar, and rum made from molasses, supplied by slave traders used to buy more slaves. Similar circular trade in salted cod-fish and slaves between Britain, America, Africa, the Caribbean and Latin America. Ships returning from delivering slaves to Brazil took maize, cassava, sweet potato, peanuts and beans to Africa.
In industrialised countries, scale of processing increased during Industrial Revolution to meet needs of growing urban populations, but processes still based on craft skills, handed down within families. Cocoa from West Africa brought to Europe and the first chocolate company began operation. Artificial refrigeration first demonstrated in Scotland.
First ‘new’ food process developed in France. Parisian brewer and pickler, Nicholas Appert, opened first ‘vacuum bottling factory’ (cannery) boiling meat and vegetables, sealing them in jars using corks and tar. Five years later, he won a 12 000 Franc prize from Napoleon Boneparte for preserving foods for military and naval forces. Artificial refrigerators produced commercially.
High pressure processing developed in the USA to preserve milk, fruit juices and meat but abandoned due to difficulties in manufacturing pressure vessels. Resumed in 1980s in Japan and commercialised in 1990. ‘Instant’ coffee invented. Transparent ‘cellophane’ wrapping patented in France.
Specialist electric machinery, including dough mixers, food cutters and potato peelers developed by the Hobart Co. in the USA. Plate heat exchanger invented. Ohmic heating developed for milk pasteurisation, but then abandoned. Research resumed in 1980s after new materials and controls were developed.
Sources: Adapted from: Levanduski, M., 2020a. History of Food Processing, Part 1. Million BC – 3500 BC.Nutrition Tribune. Available at https://nutritiontribune.com/history-of-food-processing-part-1 (last accessed September 2021); Levanduski, M., 2020b. History of Food Processing, Part 2. Modern Era of Processing.Nutrition Tribune. Available at https://nutritiontribune.com/history-of-food-processing-part-2 (last accessed September 2021); WRI, 2016. Creating a Sustainable Food Future. World Resources Report, World Resources Institute. Available at www.wri.org/our-work/topics/food (last accessed September 2021); Ohlsson, T., 2014. Sustainability and food production. In: Motarjemi, Y. and Lelieveld, H. (Eds.), Food Safety Management: A Practical Guide for the Food Industry. Academic Press, San Diego, CA. pp. 10851098. https://doi.org/10.1016/B978-0-12-381504-0.00043-3; Kurlansky, M., 2002. Salt: A World History. Vintage, Random House, London. ISBN: 978-0099281993; Kurlansky, M., 1997. Cod: A Biography of the Fish That Changed the World. Vintage, Random House, London. ISBN: 978-0099268703; and Trager, J., 1995. The Food Chronology, Aurum Press, London. ISBN 13: 9781854103994
FIGURE1 Timelinefordevelopmentoffoodprocessing.
Cured canned ‘shoulder of pork and ham’ (Spam) developed and used to help feed soldiers in World War II. Food extruder developed for snackfood pellets and pasta. Dole aseptic process developed for soups, specialty sauces, fruits and dairy products. ‘Luxury’ markets for canned tropical fruits, snackfoods and convenience foods developed. Food science and technology first taught at university level.
In industrialised economies, increased ownership of refrigerators, freezers and microwave ovens reduced demand for processed foods with a long shelf life at ambient temperature. Demand increased for ‘healthy’ or ‘natural’ foods with fewer synthetic additives. Development of functional foods containing probiotic microorganisms or cholesterol-reducing ingredients. ‘Minimal’ processing methods developed that reduced damage to organoleptic and nutritional properties, including processing using highpressures and pulsed electric fields. Low-fat, sugar-free or low-salt products introduced. Developments in information and communications technologies, later including the internet and cloud computing, led to global sourcing of raw materials, production and distribution (or ‘global value chains’).
Present day
Increased demand for organic ingredients and plant-based alternatives to meat products. Increasingly sophisticated levels of microprocessor control of equipment and computer control of processing operations, warehousing and distribution logistics. Manufacturers’ focus to reduce resource use and processing costs, enable rapid change-over between shorter production runs, improve product quality, records for management, traceability, food safety and quality assurance. Entire processes automated. Sustainability’ became a key concept in food processing to reduce use of resources, energy, pollution and waste production in response to increased public awareness of environmental impacts.
TABLE1 Examplesofunitoperationsinfoodprocessing.
Stageinprocessa
Examplesofunitoperations
RawmaterialpreparationCleaningfoods,sortingorgrading,peeling,coring,skinning Extractionandseparationof foodcomponents
Centrifugation,filtration,expression,solventextraction, membraneseparation
SizereductionChopping,cutting,slicingdicing,mincing,shredding,flaking, milling(powdersorpastes),emulsification,homogenisation
MixingBlending,dispersion,kneading
FormingMoulding,depositing,extrusion,3Dprinting
CoatingEnrobing,dusting,breading,panning,microencapsulation
Processing—near-ambient temperatures
Fermentation,highpressureprocessing,irradiation,pulsed electricfields,pulsedlight
Processing—heatingBlanching,cooking(simmering,boiling,steaming,braising, stewing),pasteurization,sterilisation(canning,aseptic/UHT), baking/roasting,extrusioncooking,frying,dielectric,ohmicand infraredheating
Processing—reduced temperature
Processing—moistureremoval usingheat
Processing—moistureremoval withoutheat
Hydrocooling,chilling,freezing
Dehydration,evaporation,distillation
Freezedrying,freezeconcentration
PostprocessingFilling,packaging,labelling,checkweighing,metaldetection, storage(ambient,chill,modifiedatmosphere,frozen),distribution
aEachstageinaprocessalsoinvolvestheunitoperationofmaterialshandling(usingpumps,conveyors,trucks,etc.)andmayalsoinvolvefoodinspection andanalyses,andtheapplicationofqualityassuranceprocedures.
Decisionsonwhichunitoperationstoselectneedtotakeintoaccountthenatureoftherawmaterialsandingredients,theintendedchangestoorganolepticandnutritionalqualities,theintendedreductionsinmicroorganismsand/or inactivationofenzymesandtherequiredproductshelflife.Aflowchartisavisualrepresentationofthesequenceof stagesanddecisionsneededinaprocess,linkedbyconnectinglinesanddirectionalarrows.Thisenablesareadertofollowaprocessfromthebeginningtotheend.Detailsoftheconstructionofflowchartsareavailablefromsoftwaresuppliers(e.g. Smartdraw,2021),andexamplesofflowchartsareshownin Fig.2 andFig.24.1.
Therearethreetypesofprocessingusedinnearlyallunitoperations;batch,semicontinuousandcontinuous.In batchprocessing,onebatchofproductismadebeforethenextisstarted.Semicontinuousprocesseshavesomeoperationsthatarebatchandothersthatarecontinuous(e.g.inabakeryanumberofbatchmixersandmouldingmachines producedoughthatisloadedinturnintoanoventhatoperatescontinuously,withsubsequentpackagingalsooperating continuously).Theadvantagesofbatchprocessingareitsflexibilitytoeasilychangeproducts,andtheequipmentis likelytobelessexpensiveandhavesimplercontrolsthatcontinuousequipment.Additionally,intheeventofafailure onlyonebatchwillbeaffected.Theadvantagesofcontinuousprocessingaremoreconsistentqualityoftheproduct, lowerlabourrequirementsthanprocessesthatusebatchequipmentandgreatersuitabilityforlarge-scaleproduction.
2Thefoodindustryinthefuture Untilrecently,consumershadlittledirectinfluenceontheoperationsoffoodcompanieswithonlyindirectinfluence viatheirpurchasingdecisions.Thishasnowchangedinindustrialisedcountriesduetotheincreasinglywidespreaduse ofinformationtechnology,whichhasenabledconsumerstoaccess,shareandquestioninformationaboutprocessed foodproductsandtheirmanufacture.Theyhavedevelopedanunderstandingofwhathappenstofoodsalongthewhole supplychain(sometimestermed‘fromfarmtofork’or‘frompaddocktoplate’).Thishaschangedthewayinwhich
Ferment under water for 3 – 4 days, ambient temperature
Wash/sieve to remove fibre
Filter/press to remove water
Slice to large pieces
Ferment under water for 3 – 4 days, ambient temperature
Grate to a paste
Ferment in water for 3 – 4 days, ambient temperature
Filter/press to remove water
Sieve wet cake to form grits
Sieve to separate fibre
Sieve or mill to break large granules
FIGURE2 Unitoperationsusedtoproducethreeproductsfromcassava.Note:Differencesinthesequenceofoperationsandmethodsusedto removewater,resultinproductswithverydifferenteatingqualities.
manufacturersrelatetoconsumersandpromotetheirimagetothegeneralpublic.Environmental,ethicalandsustainabilityconsiderationsarenowtotheforeinmanufacturers’businessstrategiesandwaysofoperating.Withmobile phonetechnologyandaccesstotheinternet,consumersworldwideareexpectedtodevelopsimilarunderstandingand concernsabouttheprocessedfoodsthattheybuyandconsume,withsimilareffectsontheoperationsoffoodcompanies inmostcountries.
3Dmodellingsoftwareisnowusedtodesignmachinery,factorylayoutsandproductionflows(Bakalisetal.,2015). ComputerizedvirtualisationusingaCloud-based‘digitaltwin’allowsanentiremanufacturingprocesstobecreatedvirtually.Designerscanperformmodellingandtestingoftheprocessbeforeinvestingtimeandmoneyintheconstruction andcommissioningofproductionlines.Afterthemanufacturinghasstarted,thevirtualplantisabletomakedecisions usingdatafromprocesssensorstooperateaprocessinrealtime(Hartonoetal.,2013).Additionally,anewapproachto manufacturing,sometimestermed‘thefourthindustrialrevolution’or‘Industry4.0’,mightinfuturerevolutionisefood manufacture.ItinvolvestheuseoftheInternetofThings(anetworkofphysicalobjectsthathavesensors,softwareand othertechnologiesthatenablesthemtobeconnectedandexchangedatawithotherdevicesandsystemsusingthe Internet).Thisinterconnectivity,or‘digitalmanufacturing’,isnowbeingdesignedintoallaspectsofrawmaterialsupply,processinganddistribution.Italsoenablesremotediagnosticsofboththeprocessandindividualpiecesofequipment.Networkscanbeusedtoremotelymanageaprocessandcontrolequipment,predictmaintenancerequirementsto
Harvested cassava tubers
maximizeequipmentreliabilityandoptimiseenergyconsumption(AppelqvistandDeWet,2021;Martin,2019).Atthe timeofwriting,digitalmanufacturingisnotwidespreadinthefoodindustryworldwide,butitmayturnouttobethe futureoffoodprocessing.
References Appelqvist,I.,DeWet,H.,2021.TheFutureofFoodManufacturing:NewDigitalRealities.AureconGroupPty.Ltd.Availableat.Availablefrom: www.aurecongroup.com/thinking/thinking-papers/future-food-manufacturing-digital-realities (lastaccessedNovember2021).
Bakalis,S.,Knoerzer,K.,Fryer,P.J.(Eds.),2015.ModelingFoodProcessingOperations.WoodheadPublishing,Cambridge.Availablefrom: https:// doi.org/10.1016/C2013-0-16519-1
Hartono,D.,Joglekar,G.,Okos,M.,2013.Useofcomputersinthedesignoffoodmanufacturingfacilities.In:Baker,C.(Ed.),HandbookofFood FactoryDesign.Springer,NewYork,NY,pp.257 279.Availablefrom: https://doi.org/10.1007/978-1-4614-7450-0_10
Kurlansky,M.,1997.Cod:ABiographyoftheFishThatChangedtheWorld.Vintage,RandomHouse,London,ISBN:978-0099268703. Kurlansky,M.,2002.Salt:AWorldHistory.Vintage,RandomHouse,London,ISBN:978-0099281993.
Levanduski,M.,2020a.HistoryofFoodProcessing,Part1.MillionBC—3500BC.NutritionTribune.Availableat https://nutritiontribune.com/history-of-food-processing-part-1 (lastaccessedNovember2021).
Levanduski,M.,2020b.HistoryofFoodProcessing,Part2.ModernEraofProcessing.NutritionTribune.Availableat https://nutritiontribune.com/history-of-food-processing-part-2 (lastaccessedNovember2021).
Martin,N.,2019.HowTechnologyIsTransformingtheFoodIndustry.Forbes.Availableat www.forbes.com/sites/nicolemartin1/2019/04/29/howtechnology-is-transforming-the-food-industry/?sh 5 36ca327c20a3 (www.forbes.com)(lastaccessedNovember2021).
Ohlsson,T.,2014.Sustainabilityandfoodproduction.In:Motarjemi,Y.,Lelieveld,H.(Eds.),FoodSafetyManagement:APracticalGuideforthe FoodIndustry.AcademicPress,SanDiego,CA,pp.1085 1098.Availablefrom: https://doi.org/10.1016/B978-0-12-381504-0.00043-3 SmartDraw,2021.Flowchart.SmartDrawLLC.Availableat www.smartdraw.com/flowchart (lastaccessedNovember2021).
Trager,J.,1995.TheFoodChronology.AurumPress,London,ISBN:9781854103994. WRI,2016.CreatingaSustainableFoodFuture.WorldResourcesReport,WorldResourcesInstitute.Availableat www.wri.org/our-work/topics/food (lastaccessedNovember2021).
Furtherreading Kiple,K.F.,Ornelas,K.(Eds.),2000.TheCambridgeWorldHistoryofFood,Vols1&2.CambridgeUniversityPress,NewYork,ISBN: 9780521402149(v.1);9780521402156(v.2).
Chapter1 Propertiesoffoodsandprinciplesof processing Thischapterfirstdescribesphysicalandbiochemicalpropertiesoffoods,followedbyimportantfoodengineeringprinciples,includingheatandmasstransfer,fluidflow,andphaseandglasstransitions.Itthendescribestheeffectsofheat onfoodsandmicroorganisms,methodstoreduceenergyconsumptioninprocessingandmethodstomonitorandcontrol processes.Thechapterconcludeswithhygienicdesign,cleaningandsanitationofprocessingfacilities,andequipment andmethodstoreducewaterconsumptionandwasteproduction.Theseaspectsareexpandedanddevelopedinsubsequentchaptersthatdescribeindividualunitoperations.
Journalsthatincluderesearchinfoodscienceandt echnologyarelistedwithlinkstoeachpublicationat http://www.scimagojr .com/journalrank.php subjectcategory‘FoodScience’ .Suppliersoffood-processing services,includingmanufacturersofprocessingequipmen t,controlandautomationsys tems,suppliersofingredientsandpackaging,sanitatio nandfoodsafetyequipment, arelistedatFoodMaster( http://www.foodmaster.com/ directories ).
1.1Physicalproperties Thephysicalpropertiesoffoods,suchasdensity,geometry,opticalandacousticproperties,areimportantto determinetheoptimalmaturity,ripeningandothereat ingandprocessingqualitiesoffreshproduce.Knowledge ofproperties,suchasthermalconductivity,specificheat,o rrheological,electricalanddielectricproperties,is essentialforthedesignandoperationoffoodprocesse sthatconvertrawmaterialsintomorepalatableand shelf-stableproducts.Thesepropertiesalsoinfluence thechoiceofpackagingmaterialsandstorageconditions forprocessedfoods.
Manyofthecharacteristicsthatdefinefoodquality(e.g.texture,structure,appearance)andstability(e.g.water activity)arelinkedtophysicalproperties.Thesepropertiesareexpandedoninchaptersthatdescribeindividualunit operationswheretheyareparticularlyrelevant(e.g.viscosityinfluidflow,particlesizeinsizereduction,thermalpropertiesinheattransfer).
Thefollowingsectiondescribesthephysicalpropertiesoffoodsandothermaterials,beginningwiththedensityof solidsandspecificgravity(SG)ofliquids.Thesearefollowedbydescriptionsofviscosity,surfaceactivity,wateractivityandredoxpotential.
Furtherinformationonthephysicalpropertiesoffoodsisgivenby Teferra(2019), Berk(2018a), Singhand Heldman(2014a), Rahman(2014), SchilkeandMcGuire(2014), Arana(2012) and Delgadoetal.(2012),andforindividualcommoditygroupsby Sa ´ nchezandPere ´ z(2012) fordairyproducts, Arozarenaetal.(2012) forcerealproducts, and Insaustietal.(2012) formeatproducts.Theelectricalpropertiesoffoodsaredescribedby DevandRaghavan (2012) andinSection18.1.
1.1.1Densityandspecificgravity 1.1.1.1Solidfoods
ThedensityofamaterialisequaltoitsmassdividedbyitsvolumeandhasSIunitsofkgm 3.Examplesofthedensity ofsolidfoodsandothermaterialsusedinfoodprocessingareshownin Table1.1 andexamplesofdensitiesofwater andotherliquidsareshownin Table1.2 and Table1.3.Thedensityofmaterialsisnotconstantandchangeswith
https://doi.org/10.1016/B978-0-323-85737-6.00007-8
