ebook img

Fundamentals of food process engineering PDF

584 Pages·2007·12.172 MB·English
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview Fundamentals of food process engineering

Fundamentals of Food Process Engineering Third Edition FOOD SCIENCE TEXT SERIES The Food Science Text Series provides faculty with the leading teaching tools. The Editorial Board has outlined the most appropriate and complete content for each food science course in a typical food science program, and has identified textbooks of the highest quality, written by leading food science educators. Series Editor Dennis R. Heldman, Ph.D.,Heldman Associates, San Marcos, California Editorial Board David A. Golden, Ph.D., Professor of Food Microbiology, Department of Food Science and Technology, University of Tennessee Richard W. Hartel,Professor of Food Engineering, Department of Food Science, University of Wisconsin Hildegarde Heymann,Professor of Food Sensory Science, Department of Food Science and Technology, University of California—Davis Joseph H. Hotchkiss,Professor, Institute of Food Science and Institute for Comparative and Environmental Toxicology, and Chair, Food Science Department, Cornell University Michael G. Johnson, Ph.D.,Professor of Food Safety and Microbiology, Department of Food Science, University of Arkansas Joseph Montecalvo, Jr.,Professor, Department of Food Science and Nutrition, California Polytechnic and State University—San Luis Obispo S. Suzanne Nielsen,Professor and Chair, Department of Food Science, Purdue University M. Shafiur Rahman, Ph.D.,Associate Professor and Head, Department of Food Science and Nutrition, Sultan Qaboos University, Oman Juan L. Silva,Professor, Department of Food Science, Nutrition and Health Promotion, Mississippi State University Titles Elementary Food Science, Fourth Edition,Ernest R. Vieira (1996) Essentials of Food Sanitation,Norman G. Marriott (1997) Essentials of Food Science, Second Edition,Vickie A. Vaclavik and Elizabeth W. Christian (2003) Food Analysis, Third Edition,S. Suzanne Nielsen (2003) Food Analysis Laboratory Manual,S. Suzanne Nielsen (2003) Food Science, Fifth Edition,Norman N. Potter and Joseph H. Hotchkiss (1995) Fundamentals of Food Process Engineering, Third Edition,Romeo T. Toledo (2007) Introduction to Food Processing,P.G. Smith (2003) Modern Food Microbiology, Seventh Edition,James M. Jay, Martin J. Loessner, and David A. Golden (2005) Physical Properties of Food, Serpil Sahin and Servet Gülüm Sumnu (2006) Principles of Food Chemistry, Third Edition,John M. de Man (1999) Principles of Food Processing,Dennis R. Heldman and Richard W. Hartel (1997) Principles of Food Sanitation, Fifth Edition,Norman G. Marriott and Robert B. Gravani (2006) Sensory Evaluation of Food: Principles and Practices,Harry T. Lawless and Hildegarde Heymann (1998) Fundamentals of Food Process Engineering Third Edition Romeo T. Toledo University of Georgia Athens, Georgia Romeo T. Toledo Department of Food Science and Technology University of Georgia Athens, GA 30602 USA [email protected] Library of Congress Control Number: 2005935292 ISBN-10: 0-387-29019-2 e-ISBN-10: 0-387-29241-1 ISBN-13: 978-0-387-29019-5 e-ISBN-13: 978-0-387-29241-0 Printed on acid-free paper. First and second editions ©1999, 1991 by Aspen Publishers, Inc. All rights reserved. ©2007 Springer Science+Business Media, LLC All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. 9 8 7 6 5 4 3 2 1 springer.com Preface Since the publication of the first edition in 1981 and the second edition in 2001, this textbook has beenwidelyadoptedforFoodEngineeringcoursesworldwide.Theauthorexpresseshisgratitudeto colleagues who have adopted this textbook and to those who have made constructive criticisms on thematerial.Thisneweditionnotonlyincorporateschangessuggestedbycolleagues,butadditional material has been added to include facilitated problem solving using a computer, and new food processing and food product technologies. New sections have been added in most of the chapters reflectingthecurrentstateofthetechnology.Theexpandedcoveragemayresultinnotenoughtime availableinaschooltermtocoverallareas;therefore,instructorsareadvisedtocarefullyperusethe bookandselectthemostappropriatesectionstocoverinaschoolterm.Theadvantageoftheexpanded coverageistheeliminationoftheneedforasupplementarytextbook. Thesuccessofthistextbookhasbeenattributedtotheexpansivecoverageofsubjectareasspecified intheInstituteofFoodTechnologistsmodelcurriculumforfoodsciencemajorsintheUnitedStatesof Americaandtheuseofexamplesutilizingconditionsencounteredinactualfoodprocessingoperations. Thisthemecontinuesinthethirdedition.Inadditiontotheemphasisonproblemsolving,technological principlesthatformthebasisforaprocessarepresentedsothattheprocesscanbebetterunderstood and selection of processing parameters to maximize product quality and safety can be made more effective. The third edition incorporates most of what was in the second edition with most of the material updated to include the use of computers in problem solving. Use of the spreadsheet and macros such as the determinant for solving simultaneous linear equations, the solver function, and programminginVisualBASICareusedthroughoutthebook.Themanualproblem-solvingapproach hasnotbeenabandonedinfavorofthecomputerapproach.Thus,userscanstillapplytheconcepts to better understand a process rather than just mechanically entering inputs into a pre-programmed algorithm. Entirelynewsectionsincludeenthalpychangecalculationsinfreezingbasedonthefreezingpoint depression,evaporativecooling,interpretationofpumpperformancecurves,determinationofshape factorsinheatexchangebyradiation,unsteady-stateheattransfer,kineticdataforthermaldegrada- tionoffoodsduringthermalprocessing,pasteurizationparametersforshelf-stablehigh-acidfoodsand long-liferefrigeratedlow-acidfoods,high-pressureprocessingoffluidandpackagedfoods,concen- tration of juices, environmentally friendly refrigerants, modified atmosphere packaging of produce, sorptionequationsforwateractivityofsolidfoods,theosmoticpressureandwateractivityrelation- ships, vacuum dehydration, new membranes commercially available for food processing and waste treatment,andsupercriticalfluidextraction. v vi Preface This edition contains much new hard-to-find data needed to conduct food process engineering calculationsandwillbeveryusefulasasourcebookofdataandcalculationtechniquesforpracticing foodengineers. Athens,Georgia RomeoT.Toledo Contents Preface............................................................................ v 1 ReviewofMathematicalPrinciplesandApplicationsinFoodProcessing............ 1 1.1 GraphingandFittingEquationstoExperimentalData........................... 1 1.1.1 VariablesandFunctions.............................................. 1 1.1.2 Graphs............................................................. 2 1.1.3 Equations.......................................................... 2 1.1.4 LinearEquations.................................................... 3 1.1.5 NonlinearEquations................................................. 4 1.2 LinearizationofNonlinearEquations......................................... 5 1.3 NonlinearCurveFitting..................................................... 6 1.4 LogarithmicandSemi-LogarithmicGraphs.................................... 8 1.5 InterceptofLog-LogGraphs................................................ 14 1.6 RootsofEquations......................................................... 16 1.6.1 Polynomials........................................................ 16 1.6.1.1 QuadraticEquation........................................... 16 1.6.1.2 Factoring.................................................... 16 1.6.1.3 IterationTechnique........................................... 17 1.7 ProgrammingUsingVisualBASICforApplicationsinMicrosoftExcel........... 18 1.8 UseofSpreadsheetstoSolveEngineeringProblems............................ 20 1.9 SimultaneousEquations .................................................... 23 1.9.1 Substitution ........................................................ 23 1.9.2 Elimination......................................................... 23 1.9.3 Determinants....................................................... 25 1.10 SolutionstoaSystemofLinearEquationsUsingthe“Solver”MacroinExcel...... 27 1.11 PowerFunctionsandExponentialFunctions................................... 29 1.12 LogarithmicFunctions...................................................... 31 1.13 DifferentialCalculus....................................................... 32 1.13.1 DefinitionofaDerivative............................................. 32 1.13.2 DifferentiationFormulas ............................................. 33 1.13.3 MaximumandMinimumValuesofFunctions........................... 35 1.14 IntegralCalculus........................................................... 38 1.14.1 IntegrationFormulas................................................. 38 vii viii Contents 1.14.2 IntegrationTechniques............................................... 39 1.14.2.1 Constants.................................................. 39 1.14.2.2 IntegrationbyParts.......................................... 39 1.14.2.3 PartialFractions............................................. 39 1.14.2.4 Substitution................................................ 39 1.15 GraphicalIntegration....................................................... 41 1.15.1 RectangularRule.................................................... 41 1.15.2 TrapezoidalRule.................................................... 42 1.15.3 Simpson’sRule..................................................... 42 1.16 DifferentialEquations...................................................... 43 1.17 FiniteDifferenceApproximationofDifferentialEquations....................... 44 Problems...................................................................... 46 SuggestedReading.............................................................. 50 2 UnitsandDimensions.......................................................... 51 2.1 DefinitionofTerms ........................................................ 51 2.2 SystemsofMeasurement.................................................... 52 2.3 TheSISystem............................................................. 52 2.3.1 UnitsinSIandTheirSymbols ........................................ 52 2.3.2 PrefixesRecommendedforUseinSI................................... 53 2.4 ConversionofUnits........................................................ 54 2.4.1 Precision,Rounding-OffRule,SignificantDigits......................... 54 2.5 TheDimensionalEquation.................................................. 55 2.6 ConversionofUnitsUsingtheDimensionalEquation........................... 55 2.7 TheDimensionalConstant(G ).............................................. 57 c 2.8 DeterminationofAppropriateSIUnits........................................ 57 2.9 DimensionalConsistencyofEquations........................................ 58 2.10 ConversionofDimensionalEquations ........................................ 59 Problems...................................................................... 61 SuggestedReading.............................................................. 63 3 MaterialBalances.............................................................. 65 3.1 BasicPrinciples ........................................................... 65 3.1.1 LawofConservationofMass......................................... 65 3.1.2 ProcessFlowDiagrams .............................................. 65 3.1.3 SystemBoundaries.................................................. 67 3.1.4 TotalMassBalance.................................................. 67 3.1.5 ComponentMassBalance............................................ 69 3.1.6 Basisand“TieMaterial” ............................................. 71 3.2 MaterialBalanceProblemsInvolvedinDilution,Concentration, andDehydration........................................................... 72 3.2.1 SteadyState........................................................ 72 3.2.2 VolumeChangesonMixing........................................... 73 3.2.3 ContinuousVersusBatch............................................. 74 3.2.4 Recycle............................................................ 75 3.2.5 UnsteadyState...................................................... 77 3.3 BlendingofFoodIngredients................................................ 80 3.3.1 TotalMassandComponentBalances................................... 80 Contents ix 3.3.2 UseofSpecifiedConstraintsinEquations............................... 85 3.4 MultistageProcesses........................................................ 89 Problems...................................................................... 98 SuggestedReading.............................................................. 103 4 GasesandVapors.............................................................. 105 4.1 EquationsofStateforIdealandRealGases..................................... 105 4.1.1 TheKineticTheoryofGases............................................ 105 4.1.2 AbsoluteTemperatureandPressure...................................... 106 4.1.3 QuantityofGases ..................................................... 107 4.1.4 TheIdealGasEquation................................................. 108 4.1.4.1 P-V-TRelationshipsforIdealGases............................... 108 4.1.5 vanderWaal’sEquationofState......................................... 110 4.1.6 CriticalConditionsforGases............................................ 112 4.1.7 GasMixtures ......................................................... 112 4.2 Thermodynamics ........................................................... 114 4.2.1 ThermodynamicVariables.............................................. 115 4.2.2 TheRelationshipBetweenC andC forGases............................ 116 p v 4.2.3 P-V-TRelationshipsforIdealGasesinThermodynamicProcesses............ 117 4.2.4 ChangesinThermodynamicProperties,Work,andHeatAssociated withThermodynamicProcesses ......................................... 117 4.2.5 WorkandEnthalpyChangeonAdiabaticExpansionorCompression ofanIdealGas........................................................ 118 4.2.6 WorkandEnthalpyChangeonIsothermalExpansionorCompression ofanIdealGas........................................................ 118 4.3 Vapor-LiquidEquilibrium.................................................... 119 4.3.1 TheClausius-ClapeyronEquation........................................ 120 4.3.2 LiquidCondensationfromGasMixtures.................................. 120 Problems...................................................................... 123 SuggestedReading.............................................................. 124 5 EnergyBalances............................................................... 125 5.1 GeneralPrinciples .......................................................... 125 5.2 EnergyTerms .............................................................. 126 5.2.1 Heat................................................................. 126 5.2.2 HeatContent,Enthalpy................................................. 126 5.2.3 SpecificHeatofSolidsandLiquids...................................... 126 5.3 EnthalpyChangesinFoodsDuringFreezing.................................... 131 5.3.1 CorrelationEquationsBasedonFreezingPointsofFoodProducts UnmodifiedfromtheNaturalState....................................... 131 5.3.2 EnthalpyChangesDuringtheFreezingofFoodsCalculated fromMolalityofLiquidWaterFractionoftheFood........................ 133 5.3.3 FreezingPointDepressionbySolutes .................................... 134 5.3.4 AmountofLiquidWaterandIceatTemperaturesBelowFreezing............ 134 5.3.5 SensibleHeatofWaterandIceatTemperaturesBelowthe FreezingPoint ........................................................ 134 5.3.6 TotalEnthalpyChange................................................. 135 5.3.7 SpecificHeatsofGasesandVapors...................................... 136 x Contents 5.4 PropertiesofSaturatedandSuperheatedSteam.................................. 138 5.4.1 TheSteamTables...................................................... 139 5.4.1.1 TheSaturatedSteamTable....................................... 139 5.4.1.2 TheSuperheatedSteamTables................................... 141 5.4.1.3 DoubleInterpolationfromSuperheatedSteamTables................ 142 5.4.2 PropertiesofSteamHavingLessThan100%Quality....................... 143 5.5 HeatBalances.............................................................. 143 Problems...................................................................... 149 SuggestedReading.............................................................. 152 6 FlowofFluids................................................................. 153 6.1 TheConceptofViscosity .................................................... 153 6.2 Rheology.................................................................. 155 6.2.1 Viscometry........................................................... 155 6.2.1.1 ViscometersBasedonFluidFlowThroughaCylinder............... 156 6.2.1.2 DerivationofthePoiseuilleEquation.............................. 156 6.2.1.3 VelocityProfileandShearRateforaPowerLawFluid............... 158 6.2.1.4 GlassCapillaryViscometers ..................................... 160 6.2.1.5 ForcedFlowTubeorCapillaryViscometry......................... 161 6.2.1.6 EvaluationofWallEffectsinTubeViscometry ..................... 166 6.2.1.7 GlassCapillaryViscometerUsedasaForcedFlowViscometer ....... 167 6.2.2 EffectofTemperatureonRheologicalProperties........................... 170 6.2.3 BackExtrusion........................................................ 172 6.2.4 DeterminationofRheologicalPropertiesofFluidsUsing RotationalViscometers................................................. 178 6.2.4.1 WideGapRotationalViscometer................................. 180 6.2.4.2 WideGapViscometerwithCylindricalSpindles.................... 182 6.3 ContinuousViscosityMonitoringandControl................................... 186 6.3.1 CapillaryViscometer................................................... 186 6.3.2 RotationalViscometer.................................................. 186 6.3.3 ViscositySensitiveRotameter........................................... 186 6.4 FlowofFallingFilms........................................................ 187 6.4.1 FilmsofConstantThickness............................................ 187 6.4.2 Time-DependentFilmThickness......................................... 189 6.4.3 ProcessesDependentonFluidFilmThicknesses........................... 192 6.5 TransportationofFluids...................................................... 193 6.5.1 MomentumBalance ................................................... 193 6.5.2 TheContinuityPrinciple................................................ 195 6.6 FluidFlowRegimes......................................................... 196 6.6.1 TheReynoldsNumber ................................................. 196 6.6.2 PipesandTubes....................................................... 198 6.6.3 FrictionalResistancetoFlowofNewtonianFluids......................... 198 6.6.4 FrictionalResistancetoFlowofNon-NewtonianFluids..................... 202 6.6.5 FrictionalResistanceOfferedbyPipeFittingstoFluidFlow................. 204 6.7 MechanicalEnergyBalance:TheBernoulliEquation ............................ 205 6.8 Pumps..................................................................... 210 6.8.1 TypesofPumpsandTheirCharacteristics................................. 210

See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.