Introduction to Food Process Engineering

Introduction to Food Process Engineering treats the principles of processing in a scientifically rigorous yet concise manner, and can be used as a lead in to more specialized texts for higher study. It is equally relevant to those in the food industry who desire a greater understanding of the principles of the food processes with which they work. Written from a quantitative and mathematical perspective, this textbook is not simply a descriptive treatment of food processing. The aim is to give readers the confidence to use mathematical and quantitative analyses of food processes. To further this goal, each chapter includes a large number of worked examples and problems, with solutions provided in the back of the book. The mathematics necessary to read this book is limited to elementary differential and integral calculus and the simplest kind of differential equation. This second edition includes two additional chapters, Mass Transfer Operations and Minimal Processing Technology, as well as numerous new and revised figures.

Texte du rabat

This is a new book on food process engineering which treats the principles of processing in a scientifically rigorous yet concise manner, and which can be used as a lead in to more specialized texts for higher study. It is equally relevant to those in the food industry who desire a greater understanding of the principles of the food processes with which they work. This text is written from a quantitative and mathematical perspective and is not simply a descriptive treatment of food processing. The aim is to give readers the confidence to use mathematical and quantitative analyses of food processes and most importantly there are a large number of worked examples and problems with solutions. The mathematics necessary to read this book is limited to elementary differential and integral calculus and the simplest kind of differential equation.

Contenu

Preface 1 An introduction to food process engineering 2 Dimensions, quantities and units 2.1 Dimensions and units 2.2 Definitions of some basic physical quantities 2.2.1 Velocity and speed 2.2.2 Acceleration 2.2.3 Force and momentum 2.2.4 Weight 2.2.5 Pressure 2.2.6 Work and energy 2.2.7 Power 2.3 Dimensional analysis 2.3.1 Dimensional consistency 2.3.2 Dimensional analysis 3 Thermodynamics and equilibrium 3.1 Introduction 3.1.1 Temperature and the zeroth law of thermodynamics 3.1.2 Temperature scale 3.1.3 Heat, work and enthalpy 3.1.4 Other definitions 3.2 The gaseous phase 3.2.1 Kinetic theory of gases 3.2.2 Perfect gases 3.2.3 Pure component vapour pressure 3.2.4 Partial pressure and pure component volume 3.3 The liquid-vapour transition 3.3.1 Vaporisation and condensation 3.3.2 Isotherms and critical temperature 3.3.3 Definition of gas and vapour 3.3.4 Vapour-liquid equilibrium 3.4 First law of thermodynamics 3.5 Heat capacity 3.5.1 Heat capacity at constant volume 3.5.2 Heat capacity at constant pressure 3.5.3 The relationship between heat capacities for a perfect gas 3.5.4 The pressure, volume, temperature relationship for gases 3.6 Second law of thermodynamics 3.6.1 The heat pump and refrigeration 3.6.2 Consequences of the second law 4 Material and energy balances 4.1 Process analysis 4.2 Material balances 4.2.1 Overall material balances 4.2.2 Concentration and composition 4.2.3 Component material balances 4.2.4 Recycle and by-pass 4.3 The steady-flow energy equation 4.4 Thermochemical data 4.4.1 Heat capacity 4.4.2 Latent heat of vaporisation 4.4.3 Latent heat of fusion 4.4.4 Steam tables 4.5 Energy balances 5 The fundamentals of rate processes 5.1 Introduction 5.2 Heat transfer 5.3 Momentum transfer 5.4 Mass transfer 5.5 Transport properties 5.5.1 Thermal conductivity 5.5.2 Viscosity 5.5.3 Diffusivity 5.6 Similarities between heat, momentum and mass transfer 6 The flow of food fluids 6.1 Introduction 6.2 Fundamental principles 6.2.1 Velocity and flow rate 6.2.2 Reynolds' experiment 6.2.3 Principle of continuity 6.2.4 Conservation of energy 6.3 Laminar flow in a pipeline 6.4 Turbulent flow in a pipeline 6.5 Pressure measurement and fluid metering 6.5.1 The manometer 6.5.2 The orifice meter 6.5.3 The venturi meter 6.6. Pumping of liquids 6.6.1 The centrifugal pump 6.6.2 Positive displacement pumps 6.6.3 Net positive suction head 6.6.4 Hygienic design 6.7 Non-Newtonian flow 6.7.1 Introduction 6.7.2 Stress, strain and flow 6.8 Time-independent rheological models 6.8.1 Hookean solids 6.8.2 Newtonian fluids 6.8.3 Bingham fluids 6.8.4 The power law 6.8.5 Laminar flow of power law fluids 6.8.6 Other time-independent models 6.9 Time-dependent rheological models 6.10 Visco-elasticity 6.10.1 Introduction 6.10.2 Mechanical analogues 6.11 Rheological measurements 6.11.1 Measurement of dynamic viscosity 6.11.2 Rheological measurements for non-Newtonian fluids 7 Heat processing of foods 7.1 Introduction 7.2 Conduction 7.2.1 Steady-state conduction in a uniform slab 7.2.2 Conduction in a composite slab 7.2.3 Radial conduction 7.2.4 Conduction in a composite cylinder 7.2.5 Conduction through a spherical shell 7.3 Convection 7.3.1 Film heat transfer coefficient 7.3.2 Simultaneous convection and conduction 7.3.3 Radial convection 7.3.4 Critical thickness of insulation 7.3.5 Correlations for film heat transfer coefficients 7.3.6 Overall heat transfer coefficient 7.4 Heat exchangers 7.4.1 Types of industrial heat exchanger 7.4.2 Sizing of heat exchangers 7.5 Boiling and condensation 7.5.1 Boiling heat transfer 7.5.2 Condensation 7.6 Heat transfer to non-Newtonian fluids 7.7 Principles of radiation 7.7.1 Absorption, reflection and transmission 7.7.2 Black body radiation 7.7.3 Emissivity and real surfaces 7.7.4 Radiative heat transfer 7.7.5 View factors 7.8 Microwave heating of foods 7.8.1 Microwaves 7.8.2 Generation of microwaves 7.8.3 Energy conversion and heating rate 7.8.4 Microwave ovens and industrial plant 7.8.5 Advantages and applications of microwave heating 7.9 Temperature measurement 7.9.1 Principles of temperature measurement 7.9.1 Expansion thermometers 7.9.3 Electrical methods 7.9.4 Radiation pyrometry 8 Mass Transfer 8.1 Introduction 8.2 Molecular diffusion 8.2.1 Fick's law 8.2.2 Diffusivity 8.2.3 Concentration 8.3 Convective mass transfer 8.3.1 Whitman's theory 8.3.2 Film mass transfer coefficients 8.3.3 Overall mass transfer coefficients 8.3.4 Addition of film mass transfer coefficients 8.3.5 Resistances to mass transfer in food processing 8.3.6 Effect of solubility on mass transfer coefficients 8.3.7 Alternative units for mass transfer coefficients 8.3.8 Units of Henry's constant 8.4 Binary diffusion 8.4.1 General diffusion equation 8.4.2 Other forms of the general diffusion equation 8.4.3 Diffusion through a stagnant gas film 8.4.4 Particles, droplets and bubbles 8.5 Correlations for mass transfer coefficients 8.6 Mass transfer and food packaging 9 Psychrometry 9.1 Introduction 9.2 Definitions of some basic quantities 9.2.1 Absolute humidity 9.2.2 Saturated humidity 9.2.3 Percentage saturation 9.2.4 Relative humidity 9.2.5 Relationship between percentage saturation and relative humidity 9.2.6 Humid heat 9.2.7 Humid volume 9.2.8 Dew point 9.3 Wet bulb and dry bulb temperatures 9.3.1 Definitions 9.3.2 The wet bulb equation 9.3.3 Adiabatic saturation temperature 9.3.4 Relationship between wet bulb temperature and adiabatic saturation temperature 9.4 The psychrometric chart 9.4.1 Principles 9.4.2 Mixing of humid air streams 9.5 Application of psychrometry to drying 10 Thermal processing of foods 10.1 Unsteady-state heat transfer 10.1.1 Introduction 10.1.2 The Biot number 10.1.3 Lumped analysis 10.2 Unsteady-state conduction 10.2.1 Fourier's first law of conduction 10.2.2 Conduction in a flat plate 10.2.3 The Fourier number 10.2.4 Gurney-Lurie charts 10.2.5 Heisler charts 10.3 Food preservation techniques using heat 10.3.1 Introduction to thermal processing 10.3.2 Pasteurisation 10.3.3 Commercial sterilisation 10.4 Kinetics of microbial death 10.…