Fundamentals of Food Process Engineering

463 Pages·2018·17.99 MB·English

by  Romeo T. Toledo

Food Science Text Series
Romeo T. Toledo
Rakesh K. Singh
Fanbin Kong
Fundamentals
of Food Process
Engineering
Fourth Edition
Food Science Text Series
SeriesEditor
Dennis R. Heldman, Professor, Department of Food, Agricultural, and
BiologicalEngineering,TheOhioStateUniversity
EditorialBoardMembers
John Coupland, Professor of Food Science, Department of Food Science,
PennStateUniversity
MarioFerruzzi,ProfessorofFoodScienceandNutrition,DepartmentofFood
BioprocessingandNutrition,NorthCarolinaState.
Richard W. Hartel, Professor of Food Engineering, Department of Food
Science,UniversityofWisconsin
RubénMorawicki,AssistantProfessorofFoodScience,DepartmentofFood
Science,UniversistyofArkansas
S. Suzanne Nielsen, Professor and Chair, Department of Food Science,
PurdueUniversity
JuanL.Silva,DepartmentofFoodScience,NutritionandHealthPromotion,
MississippiStateUniversity
TheFoodScienceTextSeriesprovidesfacultywiththeleadingteachingtools.
The Editorial Board has outlined the most appropriate and complete content
for each food science course in a typical food science program and has
identifiedtextbooksofthehighestquality,writtenbytheleadingfoodscience
educators.
Moreinformationaboutthisseriesathttp://www.springer.com/series/5999
(cid:129) (cid:129)
Romeo T. Toledo Rakesh K. Singh
Fanbin Kong
Fundamentals of Food
Process Engineering
Fourth Edition
RomeoT.Toledo RakeshK.Singh
DepartmentofFoodScience& DepartmentofFoodScience&
Technology Technology
UniversityofGeorgia UniversityofGeorgia
Athens,GA,USA Athens,GA,USA
FanbinKong
DepartmentofFoodScience&
Technology
UniversityofGeorgia
Athens,GA,USA
ISSN1572-0330 ISSN2214-7799 (electronic)
FoodScienceTextSeries
ISBN978-3-319-90097-1 ISBN978-3-319-90098-8 (eBook)
https://doi.org/10.1007/978-3-319-90098-8
LibraryofCongressControlNumber:2018941095
#SpringerInternationalPublishingAG,partofSpringerNature2007,2018
2ndedition#AspenPublishers,Inc.1999
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Preface
Sincethepublicationofthefirsteditionin1981,thesecondeditionin2001,
andthethirdeditionin2007,thistextbookhasbeenwidelyadoptedforFood
Engineering courses worldwide. The authors express their gratitude to
colleagues who have adopted this textbook and to those who have made
constructive criticisms on the materials in the previous editions. This new
editionnotonlyincorporateschangessuggestedbycolleagues,butadditional
materials have been added to include facilitated problem-solving using a
computer and new food processing and food product technologies, such
asepticprocessingandemergingfoodprocessingtechnologies.Newsections
have been added in most of the chapters reflecting the current state of the
technology.Theexpandedcoveragemayresultinnotenoughtimeavailable
in a school term to cover all areas; therefore, instructors are advised to
carefully peruse the book and select the most appropriate sections to cover
inaschoolterm.Theadvantageoftheexpandedcoverageistheeliminationof
theneedforasupplementarytextbook.
Thesuccessofthistextbookhasbeenattributedtotheexpansivecoverage
ofsubjectareasspecifiedintheInstituteofFoodTechnologistsmodelcurric-
ulum for food science majors in the USA and the use of examples utilizing
conditions encountered in actual food processing operations. This theme
continues in the fourth edition. In addition to the emphasis on problem-
solving, technological principles that form the basis for a process are
presented so that the process can be better understood and selection of
processing parameters to maximize product quality and safety can be made
moreeffective.Thefourtheditionincorporatesmostofwhatwasinthethird
edition with most of thematerial updated to include the useofcomputers in
problem-solving.Useofthespreadsheetandmacrossuchasthedeterminant
for solving simultaneous linear equations, the solver function, and program-
ming in Visual BASIC are used throughout the book. The manual problem-
solvingapproachhasnotbeenabandonedinfavorofthecomputerapproach.
Thus, users can still apply the conceptsto betterunderstand a processrather
thanjustmechanicallyenteringinputsintoapreprogrammedalgorithm.
Entirely new sections include enthalpy change calculations in freezing
based on the freezing point depression, evaporative cooling, interpretation
ofpumpperformancecurves,determinationofshapefactorsinheatexchange
byradiation,unsteady-stateheattransfer,kineticdataforthermaldegradation
v
vi Preface
offoodsduringthermalprocessing,pasteurizationparametersforshelf-stable
high-acid foods and long-life refrigerated low-acid foods, high-pressure
processingoffluidandpackagedfoods,concentrationofjuices,environmen-
tally friendly refrigerants, modified atmosphere packaging of produce, sorp-
tionequationsforwateractivityofsolidfoods,theosmoticpressureandwater
activity relationships, vacuum dehydration, new membranes commercially
available for food processing and waste treatment, and supercritical fluid
extraction.
Thiseditioncontainsmuchnewhard-to-finddataneededtoconductfood
process engineering calculations and will be very useful as a sourcebook of
dataandcalculationtechniquesforpracticingfoodengineers.
Athens,GA,USA RomeoT.Toledo
RakeshSingh
FanbinKong
Contents
1 UnitsandDimensions. . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . 1
1.1 DefinitionofTerms. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 SystemsofMeasurement. . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 TheSISystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3.1 UnitsinSIandTheirSymbols. . . . . . . . . . . . . 2
1.3.2 PrefixesRecommendedforUseinSI. . . . . . . . 2
1.4 ConversionofUnits. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.1 Precision,Rounding-OffRule,
andSignificantDigits. . . . . . . . . . . . . . . . . . . 3
1.5 TheDimensionalEquation. . . . . . . . . . . . . . . . . . . . . . . 4
1.6 ConversionofUnitsUsingtheDimensionalEquation. . . 4
1.7 TheDimensionalConstant(G ). . . . . . . . . . . . . . . . . . . 5
c
1.8 DeterminationofAppropriateSIUnits. . . . . . . . . . . . . . 6
1.9 DimensionalConsistencyofEquations. . . . . . . . . . . . . . 7
1.10 ConversionofDimensionalEquations. . . . . . . . . . . . . . . 7
Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
SuggestedReading. .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . 10
2 MaterialBalances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1 BasicPrinciples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1.1 LawofConservationofMass. . . . . . . . . . . . . . 11
2.1.2 ProcessFlowDiagrams. . . . . . . . . . . . . . . . . . 11
2.1.3 SystemBoundaries. . . . . . . . . . . . . . . . . . . . . 12
2.1.4 TotalMassBalance. . . . . . . . . . . . . . . . . . . . . 13
2.1.5 ComponentMassBalance. . . . . . . . . . . . . . . . 14
2.1.6 Basisand“TieMaterial”. . . . . . . . . . . . . . . . . 16
2.2 MaterialBalanceProblemsInvolvedinDilution,
Concentration,andDehydration. . . . . . . . . . . . . . . . . . . 16
2.2.1 SteadyState. . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.2 VolumeChangesonMixing. . . . . . . . . . . . . . 17
2.2.3 ContinuousVersusBatch. . . . . . . . . . . . . . . . . 18
2.2.4 Recycle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.5 UnsteadyState. . . . . . . . . . . . . . . . . . . . . . . . 20
2.3 BlendingofFoodIngredients. . . . . . . . . . . . . . . . . . . . . 22
2.3.1 TotalMassandComponentBalances. . . . . . . . 22
2.3.2 UseofSpecifiedConstraintsinEquations. . . . . 25
vii
viii Contents
2.4 MultistageProcesses. . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SuggestedReading. .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . 40
3 GasesandVapors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.1 EquationsofStateforIdealandRealGases. . . . . . . . . . . 41
3.1.1 TheKineticTheoryofGases. . . . . . . . . . . . . . 41
3.1.2 AbsoluteTemperatureandPressure. . . . . . . . . 42
3.1.3 QuantityofGases. . . . . . . . . . . . . . . . . . . . . . 43
3.1.4 TheIdealGasEquation. . . . . . . . . . . . . . . . . . 44
3.1.5 VanDerWaalsEquationofState. . . . . . . . . . . 45
3.1.6 CriticalConditionsforGases. . . . . . . . . . . . . . 47
3.1.7 GasMixtures. . . . . . . . . . . . . . . . . . . . . . . . . 47
3.2 Thermodynamics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.2.1 ThermodynamicVariables. . . . . . . . . . . . . . . . 49
3.2.2 TheRelationshipBetweenC andC
p v
forGases. . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.2.3 P-V-TRelationshipsforIdealGases
inThermodynamicProcesses. . . . . . . . . . . . . . 50
3.2.4 ChangesinThermodynamicProperties,Work,
andHeatAssociatedwithThermodynamic
Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.2.5 WorkandEnthalpyChangeonAdiabatic
ExpansionorCompressionofanIdealGas. . . . 51
3.2.6 WorkandEnthalpyChangeonIsothermal
ExpansionorCompressionofanIdealGas. . . . 52
3.3 Vapor-LiquidEquilibrium. . . . . . . . . . . . . . . . . . . . . . . 52
3.3.1 TheClausius-ClapeyronEquation. . . . . . . . . . . 53
3.3.2 LiquidCondensationfromGasMixtures. . . . . . 53
Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
SuggestedReading. .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . 56
4 EnergyBalances. . . . . . .. . . . . .. . . . . . .. . . . . .. . . . . . .. . 57
4.1 GeneralPrinciples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.2 EnergyTerms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.2.1 Heat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.2.2 HeatContent,Enthalpy. . . . . . . . . . . . . . . . . . 58
4.2.3 SpecificHeatofSolidsandLiquids. . . . . . . . . 58
4.3 EnthalpyChangesinFoodsDuringFreezing. . . . . . . . . . 63
4.3.1 CorrelationEquationsBasedonFreezing
PointsofFoodProductsUnmodified
fromtheNaturalState. . . . . . . . . . . . . . . . . . . 63
4.3.2 EnthalpyChangesDuringtheFreezing
ofFoodsCalculatedfromMolalityofLiquid
WaterFractionoftheFood. . . . . . . . . . . . . . . 64
4.3.3 FreezingPointDepressionbySolutes. . . . . . . . 64
4.3.4 AmountofLiquidWaterandIceatTemperatures
BelowFreezing. . . . . . . . . . . . . . . . . . . . . . . . 65
Contents ix
4.3.5 SensibleHeatofWaterandIce
atTemperaturesBelowtheFreezingPoint. . . . 65
4.3.6 TotalEnthalpyChange. . . . . . . . . . . . . . . . . . 65
4.3.7 SpecificHeatsofGasesandVapors. . . . . . . . . 66
4.4 PropertiesofSaturatedandSuperheatedSteam. . . . . . . . 68
4.4.1 TheSteamTables. . . . . . . . . . . . . . . . . . . . . . 68
4.4.2 PropertiesofSteamHavingLessThan100%
Quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.5 HeatBalances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
SuggestedReading. .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . 79
5 FlowofFluids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.1 TheConceptofViscosity. . . . . . . . . . . . . . . . . . . . . . . . 81
5.2 Rheology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
5.2.1 Viscometry. . . . . . . . . . . . . . . . . . . . . . . . . . . 83
5.2.2 EffectofTemperatureonRheological
Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
5.2.3 BackExtrusion. . . . . . . . . . . . . . . . . . . . . . . . 94
5.2.4 DeterminationofRheologicalProperties
ofFluidsUsingRotationalViscometers. . . . . . 99
5.3 ContinuousViscosityMonitoringandControl. . . . . . . . . 104
5.3.1 CapillaryViscometer. . . . . . . . . . . . . . . . . . . . 105
5.3.2 RotationalViscometer. . . . . . . . . . . . . . . . . . . 105
5.3.3 Viscosity-SensitiveRotameter. . . . . . . . . . . . . 106
5.4 FlowofFallingFilms. . . . . . . . . . . .. . . . . . . . . . . . . . . 106
5.4.1 FilmsofConstantThickness. . . . . . . . . . . . . . 106
5.4.2 Time-DependentFilmThickness. . . . . . . . . . . 108
5.4.3 ProcessesDependentonFluidFilm
Thicknesses. . . . . . . . . . . . . . . . . . . . . . . . . . 110
5.5 TransportationofFluids. . . . . . . . . . . . . . . . . . . . . . . . . 111
5.5.1 MomentumBalance. . . . . . . . . . . . . . . . . . . . 111
5.5.2 TheContinuityPrinciple. . . . . . . . . . . . . . . . . 112
5.6 FluidFlowRegimes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
5.6.1 TheReynoldsNumber. . . . . . . . . . . . . . . . . . . 113
5.6.2 PipesandTubes. . . . . . . . . . . . . . . . . . . . . . . 114
5.6.3 FrictionalResistancetoFlowofNewtonian
Fluids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
5.6.4 FrictionalResistancetoFlowofNon-Newtonian
Fluids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
5.6.5 FrictionalResistanceOfferedbyPipeFittings
toFluidFlow. . . . . . . . . . . . . . . . . . . . . . . . . 119
5.7 MechanicalEnergyBalance:TheBernoulliEquation. . . . 120
5.8 Pumps. . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . . .. . . . 124
5.8.1 TypesofPumpsandTheirCharacteristics. . . . . 124
5.8.2 FactorstoBeConsideredinPumpSelection. . . 124
5.8.3 PerformanceCurvesofPumps. . . . . . . . . . . . . 125
Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
SuggestedReading. .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . 132