Statistical Aspects of the Microbiological Examination of Foods, Third Edition, updates some important statistical procedures following intensive collaborative work by many experts in microbiology and statistics, and corrects typographic and other errors present in the previous edition. Following a brief introduction to the subject, basic statistical concepts and procedures are described including both theoretical and actual frequency distributions that are associated with the occurrence of microorganisms in foods. This leads into a discussion of the methods for examination of foods and the sources of statistical and practical errors associated with the methods. Such errors are important in understanding the principles of measurement uncertainty as applied to microbiological data and the approaches to determination of uncertainty.
The ways in which the concept of statistical process control developed many years ago to improve commercial manufacturing processes can be applied to microbiological examination in the laboratory. This is important in ensuring that laboratory results reflect, as precisely as possible, the microbiological status of manufactured products through the concept and practice of laboratory accreditation and proficiency testing. The use of properly validated standard methods of testing and the verification of ‘in house’ methods against internationally validated methods is of increasing importance in ensuring that laboratory results are meaningful in relation to development of and compliance with established microbiological criteria for foods.
The final chapter of the book reviews the uses of such criteria in relation to the development of and compliance with food safety objectives. Throughout the book the theoretical concepts are illustrated in worked examples using real data obtained in the examination of foods and in research studies concerned with food safety.
1. Chapter 1: Introduction - p. xxiv 2. Chapter 2: Some basic statistical concepts - p. 2 3. Chapter 3: Frequency distributions - p. 12 4. Chapter 4: The distribution of microorganisms in foods in relation to sampling - p. 45 5. Chapter 5: Statistical aspects of sampling for microbiological analysis - p. 70 6. Chapter 6: Errors associated with preparing samples for analysis - p. 101 7. Chapter 7: Errors associated with colony count procedures - p. 118 8. Chapter 8: Errors associated with quantal response methods - p. 140 9. Chapter 9: Statistical considerations of other methods in quantitative microbiology - p. 169 10. Chapter 10: Measurement uncertainty in microbiological analysis - p. 184 11. Chapter 11: Estimation of measurement uncertainty - p. 194 12. Chapter 12: Statistical process control using microbiological data - p. 227 13. Abstract - p. 227 14. What is statistical process control? - p. 229 15. Tools for statistical process control - p. 230 16. Shewhart’s control charts for variables data - p. 235 17. CUSUM charts - p. 247 18. The moving windows average - p. 255 19. Control charts for attribute data - p. 257 20. Recent developments in statistical process control - p. 264 21. Chapter 13: Validation of microbiological methods for food - p. 265 22. Chapter 14: Risk assessment and microbiological criteria for foods - p. 294 23. Subject Index - p. 319
Statistical Aspects of the Microbiological Examination of Foods, Third Edition, updates some important statistical procedures following intensive collaborative work by many experts in microbiology and statistics, and corrects typographic and other errors present in the previous edition. Following a brief introduction to the subject, basic statistical concepts and procedures are described including both theoretical and actual frequency distributions that are associated with the occurrence of microorganisms in foods. This leads into a discussion of the methods for examination of foods and the sources of statistical and practical errors associated with the methods. Such errors are important in understanding the principles of measurement uncertainty as applied to microbiological data and the approaches to determination of uncertainty.
The ways in which the concept of statistical process control developed many years ago to improve commercial manufacturing processes can be applied to microbiological examination in the laboratory. This is important in ensuring that laboratory results reflect, as precisely as possible, the microbiological status of manufactured products through the concept and practice of laboratory accreditation and proficiency testing. The use of properly validated standard methods of testing and the verification of ‘in house’ methods against internationally validated methods is of increasing importance in ensuring that laboratory results are meaningful in relation to development of and compliance with established microbiological criteria for foods.
The final chapter of the book reviews the uses of such criteria in relation to the development of and compliance with food safety objectives. Throughout the book the theoretical concepts are illustrated in worked examples using real data obtained in the examination of foods and in research studies concerned with food safety.
1. Chapter 1: Introduction - p. xxiv 2. Chapter 2: Some basic statistical concepts - p. 2 3. Chapter 3: Frequency distributions - p. 12 4. Chapter 4: The distribution of microorganisms in foods in relation to sampling - p. 45 5. Chapter 5: Statistical aspects of sampling for microbiological analysis - p. 70 6. Chapter 6: Errors associated with preparing samples for analysis - p. 101 7. Chapter 7: Errors associated with colony count procedures - p. 118 8. Chapter 8: Errors associated with quantal response methods - p. 140 9. Chapter 9: Statistical considerations of other methods in quantitative microbiology - p. 169 10. Chapter 10: Measurement uncertainty in microbiological analysis - p. 184 11. Chapter 11: Estimation of measurement uncertainty - p. 194 12. Chapter 12: Statistical process control using microbiological data - p. 227 13. Abstract - p. 227 14. What is statistical process control? - p. 229 15. Tools for statistical process control - p. 230 16. Shewhart’s control charts for variables data - p. 235 17. CUSUM charts - p. 247 18. The moving windows average - p. 255 19. Control charts for attribute data - p. 257 20. Recent developments in statistical process control - p. 264 21. Chapter 13: Validation of microbiological methods for food - p. 265 22. Chapter 14: Risk assessment and microbiological criteria for foods - p. 294 23. Subject Index - p. 319
