Infodoc : Sciences, Techniques et Culture

1 Introduction
1.1 Thermal Processing Principles
1.1.1 Thermal Processing
1.1.2 The Process
1.2 Canning Operations
1.2.1 General
1.2.2 Methods of Processing
1.3 Packaging Materials
1.3.1 Introduction
1.3.2 Metal Containers
1.3.3 Glass Containers
1.3.4 Rigid Plastic Containers
1.3.5 Retortable Pouches
1.4 Some Historical Details
References
2 Heat Transfer
2.1 Introduction
2.[...]

1 Introduction
1.1 Thermal Processing Principles
1.1.1 Thermal Processing
1.1.2 The Process
1.2 Canning Operations
1.2.1 General
1.2.2 Methods of Processing
1.3 Packaging Materials
1.3.1 Introduction
1.3.2 Metal Containers
1.3.3 Glass Containers
1.3.4 Rigid Plastic Containers
1.3.5 Retortable Pouches
1.4 Some Historical Details
References
2 Heat Transfer
2.1 Introduction
2.1.1 General Aspects
2.1.2 Mechanisms of Heat Transfer
2.2 Heat Transfer by Conduction
2.2.1 Introduction
2.2.2 Formulation of Problems Involving Conduction Heat Transfer
2.2.3 Initial and Boundary Conditions
2.2.4 Mean or Volume Average Temperatures
2.2.5 Summary of Basic Requirements
2.2.6 Some Analytical Methods for Solving the Equations
2.2.7 Some Numerical Techniques of Solution
2.2.8 Some Analytical Solutions of the Heat Transfer Equation
2.2.9 Heat Transfer in Packaged Foods by Microwave Heating
2.2.10 Dielectric Heating
2.3 Heat Transfer by Convection
2.3.1 Introduction
2.3.2 Basic Concepts in Convection Heat Transfer
2.3.3 Models for Convection Heat Transfer
2.3.4 Some Experimental Work and Correlations
2.3.5 Conclusions
2.4 Radiation Heating
2.5 Some Computer Programs
2.5.1 Conduction Heat Transfer Analysis Programs
References
3 Kinetics of Thermal Processing
3.1 Introduction
3.1.1 General Effects of Thermal Processing
3.1.2 The Nature of Microbial Behaviour
3.1.3 Other Factors Affecting Heat Resistance
3.1.4 Measuring Heat Resistance
3.1.5 The Statistical Nature of Microbial Death
3.1.6 Practical Aspects
3.2 Methods of Representing Kinetic Changes
3.2.1 Basic Kinetic Equations
3.2.2 Decimal Reduction Time
3.2.3 More Complex Inactivation Models
3.2.4 Temperature Dependence of Death Rate
3.3 Kinetics of Food Quality Factor Retention
3.3.1 Introduction
3.3.2 Kinetic Representation
3.3.3 Kinetic Factors
3.3.4 Experimental Procedures
3.3.5 Specific Components
3.6 Summary
References
4 Sterilization, Pasteurization and Cooking Criteria
4.1 Sterilization Value
4.1.1 Definitions
4.1.2 Lethal Rates
4.1.3 Reference Temperatures
4.1.4 A processing Point of View to Derive F value
4.1.5 Integrated F-values, Fs
4.1.6 F-values for Cans of Differing Sizes
4.1.7 Arrhenius Approach
4.2 Cooking Values
4.2.1 Historical Perspective
4.2.2 Origin and Rationale of Cooking Value
4.2.3 Quality Retention
4.3 Pasteurization Value
4.4 Minimally Processed Foods
4.4.1 Acidified Products
4.4.2 Pasteurized/Chilled Products
4.4.3 Electrical Methods of Heating
4.4.4 Other Processes
4.5 Process Achievement Standards
4.5.1 Sterilization
4.5.2 Cooking
References
5 Heat Penetration in Packaged Foods
5.1 Introduction
5.1.1 Heat Transfer and Product Characteristics
5.2 Experimental Determination
5.2.1 Temperature Monitoring
5.2.2 Thermocouple Errors
5.2.3 Thermocouple Calibration
5.2.4 Thermocouple Location: Slowest Heating Point
5.2.5 Model Systems
5.3 Graphical Analysis of Heat Penetration Data
5.3.1 The Linear Plot
5.3.2 The Semi-logarithmic Plot
5.3.3 Analysis of Heat Penetration Graphs
5.4 Theoretical Analysis of Heat Penetration Curves
5.4.1 Conduction-Heating Packs
5.4.2 Convection-Heating Packs
5.4.3 Computer Modeling
5.5 Factors Affecting Heat Penetration
5.5.1 Effect of Container Shape and Dimensions
5.5.2 Effect of Initial Temperature
5.5.3 Effect of Position Inside the Container
5.5.4 Effect of Headspace
5.5.5 Effect of Variation of Physical Properties with Temperature
5.5.6 Effect of External Heat-transfer Coefficients
5.5.7 Effect of Container Material and Thickness
5.5.8 Effect of Can Rotation
5.5.9 Statistical Aspects of Heat Penetration Data
5.5.10 Extrapolation of Heat Penetration Data
5.6 Simulation of Thermal Processing of Non-symmetric and Irregular-Shaped Foods Vacuum Packed in Retort Pouches: A Numerical Example
5.6.1 Reverse Engineering by 3-D Digitizing
5.6.2 Simulation of Heat Conduction Processes
5.6.3 Finite Element Analysis
5.6.4 Experimental Validation
References
6 Process Evaluation Techniques
6.1 Determination of F - Values: Process Safety
6.2 The General Method
6.2.1 Graphical Methods
6.2.2 Numerical Methods
6.2.3 An Extension of General Method: Revisited General Method (RGM)
6.3 Analytical Methods
6.3.1 Constant Temperature with Time
6.3.2 Linear Temperature Gradient
6.3.3 Exponential Temperature Rise
6.3.4 The Exponential Integral
6.4 Some Formula Methods
6.4.1 Introduction
6.4.2 Ball's Methods
6.4.3 Gillespi's Method
6.4.4 Hayakawa's Method
6.4.5 Other Methods
6.5 Mass-average Sterilizing Values
6.6 Some Factors Affecting F-Values
6.6.1 Introduction
6.6.2 Statistical Variability of F-Values
6.7 Microbiological Methods
6.7.1 Introduction
6.7.2 lnoculated Pack Method
6.7.3 Encapsulated Spore Method
6.7.4 Biological and Chemical lndicators
6.7.5 Conclusion
6.8 A Guide to Sterilization Values
6.9 Computerised Process Calculations
References
7 Quality Optimization
7.1 Introduction
7.2 Cooking versus Microbial Inactivation
7.3 Process Evaluation
7.3.1 Some Models for Predicting Nutrient and Cooking Effects
7.3.2 Some Typical C-values
7.4 Optimization of Thermal Processing Conditions
7.4.1 Graphical Approach
7.4.2 Optimization Models
7.5 Quality Assessment Through Mass Balance
7.5.1 Demonstration Examples
7.5.2 Corollary
7.6 Conclusions
References
8 Engineering Aspects of Thermal Processing
8.1 Thermal Processing Equipment
8.1.1 Introduction
8.1.2 Batch Retorts
8.1.3 Continuous Cookers
8.1.4 Heat Transfer Media
8.2 Total and Transient Energy Consumption in Batch Retort Processing
8.2.1 Mathematical Model for Food Material
8.2.2 Mass and Energy Balance During Venting
8.2.3 Mass and Energy Consumption between Venting and Holding Time (To Reach Process Temperature)
8.2.4 Mass and Energy Balance During Holding Time
8.2.5 Numerical Results
8.3 Pressures in Containers
8.3.1 Development of Internal Pressures
8.3.2 Internal Pressure Calculation
8.3.3 Processing Requirements
8.3.4 Semi-rigid Containers
8.4 Mechanical Agitation and Rotation of Cans
8.4.1 End-over-end Agitation
8.4.2 Axial Rotation and Spin Cooking
8.4.3 Steritort and Orbitort Processes
8.4.4 Shaka@ Retort Process
8.5 Commercial Pasteurizers
8.6 Computer Simulation of Fluid Dynamics Heat Transfer
8.7 Batch Processing and Retort Scheduling
8.7.1 Batch Processing Problem Structure in Canned Foods
8.7.2 Batch Processing in Canned Food Plants
8.7.3 The Hierarchical Approach
8.7.4 Retort Scheduling
8.8 Simultaneous Sterilization of Different Product Lots in the Same Retort
8.8.1 Simultaneous Sterilization Characterization
8.8.2 Mathematical Formulation for Simultaneous Sterilization
8.8.3 Computational Procedure
8.8.4 Expected Advantages on the Implementation of Simultaneous Sterilization
References
9 Retort Control
9.1 Process Instrumentation
9.1.1 Introduction
9.1.2 Temperature Measurement
9.1.3 Pressure Measurement
9.1.4 Water Level
9.1.5 Rotation Monitors
9.1.6 Lethality Measurement
9.2 Process Control
9.2.1 Introduction
9.2.2 Control Valves and Actuators
9.2.3 Interfaces
9.2.4 Control Systems
9.2.5 Computer Control
9.2.6 Process Dynamics
9.3 Retort Control
9.3.1 Control of Batch Retorts
9.3.2 Efficient and General On-line Correction of Process Deviations in Batch Retort
9.3.3 Control of Hydrostatic Sterilizers
9.3.4 Control of Continuous Reel and Spiral Pressure Cookers
9.3.5 Derived-value Control
9.3.6 Guidelines for Computer Control
9.4 lndustrial Automation of Batch Retorts
References
10 Safety Aspects of Thermal Processing
10.1 Introduction
10.2 Information Sources
10.2.1 Legislation and Codes of Practice
10.2.2 GMP Guidelines and Recommendations
10.2.3 Technical Training
10.3 Some Techniques for the Implementation of GMP
10.3.1 HACCP Techniques
10.3.2 Process Audits
10.4 Aspects of GMP
10.4.1 Identification of Critical Factors
10.4.2 Process Deviations
10.5 Thermal Process Validation
10.5.1 Process Establishment
10.5.2 Lethality Assurance
10.5.3 Records
References
Appendix A: Kinetic Factors for Microbial Inactivation
Appendix B: Kinetic Factors for Quality Attributes
Appendix C: Heat Penetration Protocols
Appendix D: FDA Food Process Filing
Index