Microbiological Analysis of Red Meat, Poultry and Eggs

365 Pages·2006·1.738 MB·English

by  G. Mead

Microbiological analysis of red meat,
poultry and eggs
Related titles:
Improving the safety of fresh meat
(ISBN-13: 978-1-85573-955-0; ISBN-10: 1-85573-955-0)
It is widely recognised that food safety depends on effective intervention
at all stages in the food chain, including the production of raw materials.
Contaminated raw materials from agricultural production increase the
hazards that subsequent processing operations must deal with, together
with the risk that such contamination may survive through to the point
of consumption. This collection provides an authoritative reference
summarising the wealth of research on reducing microbial and other
hazards in raw and fresh red meat.
Food safety control in the poultry industry
(ISBN-13: 978-1-85573-954-3; ISBN-10: 1-85573-954-2)
Consumers’ expectations about the safety of products such as poultry
meat and eggs have never been higher. The need to improve food safety
has led to renewed attention on controlling contamination at all stages of
the supply chain from ‘farm to fork’. This collection reviews the latest
research and best practice in ensuring the safety of poultry meat and
eggs, both on the farm and in subsequent processing operations.
Emerging foodborne pathogens
(ISBN-13: 978-1-85573-963-5; ISBN-10: 1-85573-963-1)
Developments such as the increasing globalisation of the food industry,
constant innovations in technologies and products, and changes in the
susceptibility of populations to disease, have all highlighted the problem of
emerging pathogens. Designed for microbiologists and QA staff in the
food industry, and food safety scientists working in governments and
academia, this collection discusses ways of identifying emerging pathogens
and includes chapters on individual pathogens, their epidemiology,
methods of detection and means of control.
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Microbiological
analysis of red meat,
poultry and eggs
Edited by
G. C. Mead
Cambridge England
Published by Woodhead Publishing Limited, Abington Hall, Abington
Cambridge CB21 6AH, England
www.woodheadpublishing.com
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Contents
Contributor contact details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
1 Microbiological testing in food safety and quality
management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
C. de W. Blackburn, Unilever Colworth, UK
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Control systems used in the food industry . . . . . . . . . . . . 2
1.3 Role of microbiological testing . . . . . . . . . . . . . . . . . . . . . . 9
1.4 Applying microbiological testing . . . . . . . . . . . . . . . . . . . . 21
1.5 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.6 Sources of further information and advice . . . . . . . . . . . . 26
1.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2 Legislation for red meat, poultry and eggs: which
way forward? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
M. Fogden, Consultant, UK
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.2 Codex Alimentarius (food code) . . . . . . . . . . . . . . . . . . . . 34
2.3 Regulation in the EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.4 EU regulation on microbiological criteria . . . . . . . . . . . . . 43
2.5 Annex I: criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.6 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.7 Sources of further information and advice . . . . . . . . . . . . 51
2.8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
vi Contents
3 Escherichia coli O157 and other VTEC in the
meat industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
I. D. Ogden, University of Aberdeen, UK
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.2 Pathogenic potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.3 Key outbreaks of E. coli O157 and other VTEC . . . . . . . 61
3.4 Occurrence in red meat and poultry . . . . . . . . . . . . . . . . . 64
3.5 Regulatory measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.6 Laboratory methods of isolation and
identifi cation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3.7 Industry measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
3.8 Consumer responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.9 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
3.10 Sources of further information and advice . . . . . . . . . . . . 75
3.11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
4 Faecal indicator organisms for red meat and poultry . . . . . . . . . . 83
G. C. Mead, Consultant, UK
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4.2 Origins and terminology of the indicator concept . . . . . . 84
4.3 Enterobacteriaceae, coliforms and E. coli . . . . . . . . . . . . . 85
4.4 Monitoring faecal contamination of meat . . . . . . . . . . . . . 92
4.5 Other indicator organisms . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4.6 Use of E. coli for determining cross-contamination . . . . 95
4.7 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 96
4.8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
5 Spoilage organisms of red meat and poultry . . . . . . . . . . . . . . . . . 101
J. E. L. Corry, University of Bristol, UK
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
5.2 Microfl ora of raw meat immediately after
slaughter (red meat and poultry) . . . . . . . . . . . . . . . . . . . . 102
5.3 Factors affecting fl ora development and
changes leading to spoilage . . . . . . . . . . . . . . . . . . . . . . . . . 103
5.4 Spoilage of vacuum-packed red meat of normal
pH due to psychrophilic or psychrotrophic
Clostridium spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
5.5 Bone taint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
5.6 Spoilage of uneviscerated poultry . . . . . . . . . . . . . . . . . . . . 109
5.7 Effect of storage temperature on spoilage . . . . . . . . . . . . 110
5.8 Metabolic products responsible for spoilage . . . . . . . . . . . 110
5.9 Isolation and identifi cation of spoilage organisms . . . . . . 112
5.10 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
5.11 Sources of further information and advice . . . . . . . . . . . . 115
5.12 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Contents vii
6 Sampling of red meat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
C. O. Gill, Lacombe Research Centre, Canada
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
6.2 Purposes of routine microbiological sampling . . . . . . . . . 123
6.3 Target organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
6.4 Sampling plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
6.5 Sampling sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
6.6 Methods of sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
6.7 Detection methods and enumeration of bacteria . . . . . . . 135
6.8 Interpretation of data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
6.9 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
6.10 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 142
6.11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
7 Sampling methods for poultry-meat products . . . . . . . . . . . . . . . . 148
G. C. Mead, Consultant, UK
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
7.2 Origins and distribution of carcass contaminants . . . . . . . 149
7.3 Microbial attachment to skin and other carcass
surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
7.4 Sampling carcasses in the processing plant . . . . . . . . . . . . 152
7.5 Methods of sampling carcasses . . . . . . . . . . . . . . . . . . . . . . 153
7.6 Sampling frozen meat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
7.7 Cut portions and other raw products . . . . . . . . . . . . . . . . . 157
7.8 Cooked, ready-to-eat products . . . . . . . . . . . . . . . . . . . . . . 158
7.9 Pooling of samples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
7.10 Sample handling and transportation . . . . . . . . . . . . . . . . . 159
7.11 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
7.12 Sources of further information and advice . . . . . . . . . . . . 160
7.13 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
8 Microbiological monitoring of cleaning and disinfection
in food plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
J. F. Rigarlsford, Consultant, UK
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
8.2 Sanitisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
8.3 Sources of product contamination . . . . . . . . . . . . . . . . . . . 168
8.4 Development of a testing programme . . . . . . . . . . . . . . . . 169
8.5 Testing plant surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
8.6 Rapid methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
8.7 Air testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
8.8 Data utilisation and limit values . . . . . . . . . . . . . . . . . . . . . 181
8.9 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
8.10 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 182
8.11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
viii Contents
9 Microbiological analysis of eggs and egg products . . . . . . . . . . . . 183
J. E. L. Corry, University of Bristol, UK
9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
9.2 Shell eggs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
9.3 Bulk liquid egg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
9.4 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
9.5 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 196
9.6 Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
9.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
10 Detection and enumeration of pathogens in meat,
poultry and egg products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
E. de Boer, Food and Consumer Product Safety
Authority (VWA), The Netherlands
10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
10.2 Cultural methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
10.3 Rapid methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
10.4 Factors in the choice of technique . . . . . . . . . . . . . . . . . . . 231
10.5 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
10.6 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 235
10.7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
11 Techniques for identifying foodborne microorganisms . . . . . . . . 246
S. M. Russell and P. C. Vasavada, University of Georgia, USA
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
11.2 Purifi cation of isolates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
11.3 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
11.4 Preliminary examination . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
11.5 Identifi cation systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
11.6 Commonly used selective and differential media . . . . . . . 255
11.7 Automated microbial identifi cation . . . . . . . . . . . . . . . . . . 258
11.8 Systems for typing isolates following identifi cation . . . . . 262
11.9 Genetic methods for typing bacterial strains . . . . . . . . . . 264
11.10 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 270
11.11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
12 Validation of analytical methods used in food
microbiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
M. Uyttendaele and J. Debevere, Gent University,
Belgium
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
12.2 Defi nition of performance characteristics . . . . . . . . . . . . . 277
12.3 Validation protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
12.4 Use of validation schemes for evaluating the
performance of alternative methods . . . . . . . . . . . . . . . . . 290
Contents ix
12.5 Application of validated methods in accredited
laboratories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
12.6 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
12.7 Sources of further information . . . . . . . . . . . . . . . . . . . . . . 300
12.8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
13 Quality Assurance in the food microbiology laboratory . . . . . . . 305
R. Wood, Food Standards Agency, UK
13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
13.2 Legislation and codes of practice . . . . . . . . . . . . . . . . . . . . 306
13.3 Accreditation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
13.4 Internal Quality Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
13.5 Profi ciency testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
13.6 Quality Assurance requirements: analytical methods . . . 319
13.7 Criteria for valid methods of analysis . . . . . . . . . . . . . . . . 322
13.8 Method validation through profi ciency testing . . . . . . . . . 323
13.9 Measurement uncertainty for the microbiologist . . . . . . . 324
13.10 Future trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
13.11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Appendix I: The ISO/IUPAC/AOAC international
harmonised protocol for profi ciency testing of (chemical)
analytical laboratories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Appendix II: Codex guidelines on measurement
uncertainty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335