Preface . . . .............................................................. xi
List of contributors . . . . . ................................................ xiii
Introduction: the chilled foods market 1
C. Dennis and M. Stringer, Campden and Chorleywood Food Research
Association
I.1 Definition . . . . ................................................ 1
I.2 Drivers in the chilled food sector . . . . ........................ 3
I.3 Overall market size . . . . ...................................... 6
I.4 Individual categories within the chilled food sector .......... 12
I.5 Conclusion . . . ................................................ 15
I.6 References . . . ................................................ 16
Part I Raw materials
1 Raw material selection: fruit and vegetables .................... 19
L. Bedford, Campden and Chorleywood Food Research Association
1.1 Introduction . . ................................................ 19
1.2 Criteria for selection . . . ...................................... 20
1.3 Specifications ................................................ 28
1.4 New trends in raw material production . . . . . ................. 30
1.5 New trends in plant breeding . ............................... 31
1.6 Conclusion . . . ................................................ 32
1.7 Sources of further information and advice . . ................. 33
1.8 References . . . ................................................ 33
Contents
2 Raw material selection: dairy ingredients ...................... 37
L. R. Early, Harper Adams University College
2.1 Introduction . . . . . . ........................................... 37
2.2 Milk composition . ........................................... 37
2.3 Functional approach . . . . . .................................... 38
2.4 Sensory properties ........................................... 39
2.5 Microbiological criteria for milk products . . . . ............... 41
2.6 Chilled dairy products and milk-based ingredients used in
chilled foods . . . . . . ........................................... 41
2.7 Chilled desserts . . . ........................................... 52
2.8 Ready meals . . . . . . ........................................... 53
2.9 Maximising quality in processing . . . . . . ...................... 53
2.10 Food safety issues ........................................... 55
2.11 Future trends . . . . . ........................................... 57
2.12 References . . . . . . . . ........................................... 58
3 Raw material selection: meat and poultry ...................... 63
S. J. James, Food Refrigeration and Process Engineering Research
Centre
3.1 Introduction . . . . . . ........................................... 63
3.2 The influence of the live animal ............................. 65
3.3 Pre- and post-slaughter handling ............................. 69
3.4 Conclusions . . . . . . . ........................................... 72
3.5 References . . . . . . . . ........................................... 73
Part II Technologies and processes
4 The refrigeration of chilled foods ............................... 79
R. D. Heap, Cambridge Refrigeration Technology
4.1 Introduction . . . . . . ........................................... 79
4.2 Principles of refrigeration .................................... 81
4.3 Safety and quality issues .................................... 81
4.4 Refrigerant fluids and the environment ...................... 82
4.5 Chilled foods and refrigeration . ............................. 83
4.6 Chilling . ..................................................... 84
4.7 Chilling equipment . . . . . . .................................... 85
4.8 Chilled storage . . . ........................................... 87
4.9 Refrigerated transport . . . . .................................... 90
4.10 Refrigerated display cabinets . . . ............................. 94
4.11 Regulations and legislation . . . . . ............................. 96
4.12 Sources of further information . . ............................. 97
4.13 References . . . . . . . . ........................................... 97
vi Contents
5 Temperature monitoring and measurement ..................... 99
M. Wolfe, Food Standards Agency, London
5.1 Introduction . . ................................................ 99
5.2 Importance of temperature monitoring . . . . . . ................. 101
5.3 Principles of temperature monitoring ........................ 102
5.4 Temperature monitoring in practice . . ........................ 105
5.5 Equipment for temperature monitoring . . . . . . ................. 116
5.6 Temperature and time–temperature indicators . . . . . . .......... 126
5.7 Temperature modelling and control . . ........................ 130
5.8 Further reading . . . . . . . . ...................................... 131
5.9 References . . . ................................................ 131
6 Chilled food packaging ........................................... 135
B. P. F. Day, Campden and Chorleywood Food Research Association
6.1 Introduction . . ................................................ 135
6.2 Requirements of chilled food packaging materials . .......... 135
6.3 Chilled food packaging materials . . . . ........................ 136
6.4 Packaging techniques for chilled food . . . . . . ................. 139
6.5 Future trends . ................................................ 147
6.6 Sources of further information ............................... 149
6.7 References . . . ................................................ 149
Part III Microbiological and non-microbiological hazards
7 Chilled foods microbiology ...................................... 153
S. J. Walker and G. Betts, Campden and Chorleywood Food Research
Association
7.1 Introduction . . ................................................ 153
7.2 Why chill? . . . ................................................ 154
7.3 Classification of growth ...................................... 154
7.4 The impact of microbial growth . . . . . ........................ 156
7.5 Factors affecting the microflora of chilled foods . . . .......... 157
7.6 Spoilage microorganisms . . . . . ............................... 162
7.7 Pathogenic microorganisms . . . ............................... 167
7.8 Temperature control . . . ...................................... 173
7.9 Predictive microbiology ...................................... 174
7.10 Conclusions . . ................................................ 178
7.11 References . . . ................................................ 179
8 Conventional and rapid analytical microbiology ................ 187
R. P. Betts, Campden and Chorleywood Food Research Association
8.1 Introduction . . ................................................ 187
8.2 Sampling . . . . . ................................................ 188
8.3 Conventional microbiological techniques . . . ................. 188
8.4 Rapid and automated methods ............................... 191
Contents vii
8.5 Microbiological methods – the future . . ...................... 214
8.6 References and further reading . ............................. 214
9 Non-microbial factors affecting quality and safety ............. 225
H. M. Brown and M. H. Hall, Campden and Chorleywood Food
Research Association
9.1 Introduction . . . . . . ........................................... 225
9.2 Characteristics of chemical reactions . . ...................... 226
9.3 Chemical reactions of significance in chilled foods . . . . . ..... 226
9.4 Characteristics of biochemical reactions . . . . . . ............... 231
9.5 Biochemical reactions of significance in chilled foods . ..... 233
9.6 Characteristics of physico-chemical reactions . ............... 238
9.7 Physico-chemical reactions of significance in chilled foods . 238
9.8 Non-microbiological safety issues of significance in chilled
foods . . ..................................................... 243
9.9 Conclusions . . . . . . . ........................................... 248
9.10 References . . . . . . . . ........................................... 248
Part IV Safety and quality issues
10 Shelf-life determination and challenge testing . . . ............... 259
G. Betts and L. Everis, Campden and Chorleywood Food Research
Association
10.1 Introduction . . . . . . ........................................... 259
10.2 Factors affecting shelf-life . . . . . . ............................. 260
10.3 Modelling shelf-life . . . . . . .................................... 268
10.4 Determination of product shelf-life . . . . ...................... 270
10.5 Maximising shelf-life . . . . .................................... 278
10.6 Challenge testing . ........................................... 279
10.7 Future trends . . . . . ........................................... 283
10.8 References . . . . . . . . ........................................... 283
11 Microbiological hazards and safe process design ............... 287
M. H. Brown, Unilever Research, Sharnbrook
11.1 Introduction . . . . . . ........................................... 287
11.2 Definitions . . . . . . . . ........................................... 290
11.3 Microbiological hazards . .................................... 304
11.4 Risk classes . . . . . . . ........................................... 307
11.5 Safe process design 1: equipment and processes . . . . . . . . ..... 308
11.6 Safe process design 2: manufacturing areas . . ............... 316
11.7 Safe process design 3: unit operations for decontaminated
products ..................................................... 323
11.8 Control systems . . ........................................... 328
11.9 Conclusions . . . . . . . ........................................... 332
11.10 References . . . . . . . . ........................................... 333
viii Contents
12 Quality and consumer acceptability . . . . . ........................ 341
S. R. P. R. Durand, HP Foods Ltd
12.1 Introduction . . ................................................ 341
12.2 What defines sensory quality? ............................... 342
12.3 Sensory evaluation techniques ............................... 344
12.4 Determining consumer acceptability . ........................ 349
12.5 Future trends and conclusion . . ............................... 351
12.6 References . . . ................................................ 352
13 The hygienic design of chilled foods plant . . . . . ................. 355
J. Holah and R. H. Thorpe, Campden and Chorleywood Food Research
Association
13.1 Introduction . . ................................................ 355
13.2 Segregation of work zones . . . . ............................... 357
13.3 High-risk barrier technology . . ............................... 363
13.4 Hygienic construction . . ...................................... 380
13.5 Equipment . . . ................................................ 389
13.6 Conclusion . . . ................................................ 394
13.7 References . . . ................................................ 394
14 Cleaning and disinfection . . ...................................... 397
J. Holah, Campden and Chorleywood Food Research Association
14.1 Introduction . . ................................................ 397
14.2 Sanitation principles . . . ...................................... 398
14.3 Sanitation chemicals . . . ...................................... 402
14.4 Sanitation methodology ...................................... 409
14.5 Sanitation procedures . . ...................................... 414
14.6 Evaluation of effectiveness . . . ............................... 416
14.7 Management responsibilities . . ............................... 421
14.8 References . . . ................................................ 423
15 Total quality management . ...................................... 429
D. J. Rose, Campden and Chorleywood Food Research Association
15.1 Introduction . . ................................................ 429
15.2 The scope of a quality system ............................... 433
15.3 Developing a quality system . . ............................... 435
15.4 Implementation . . . . . . . . ...................................... 442
15.5 Performance measuring and auditing . ........................ 446
15.6 Benefits . . . . . . ................................................ 448
15.7 Future trends . ................................................ 449
15.8 References and further reading ............................... 450
16 Legislation 451
K. Goodburn, Chilled Food Association
16.1 Introduction . . ................................................ 451
Contents ix
16.2 Food law is reactive . . . . . .................................... 451
16.3 Food laws and international trade . . . . . ...................... 452
16.4 Chilled foods are. . . . . . . . .................................... 453
16.5 Approaches to legislation .................................... 454
16.6 Codex . . ..................................................... 455
16.7 ATP . . . . ..................................................... 457
16.8 Canada . ..................................................... 458
16.9 European Union . . ........................................... 458
16.10 Australia/New Zealand . . .................................... 461
16.11 France . . ..................................................... 462
16.12 The Netherlands . . ........................................... 463
16.13 United Kingdom . . ........................................... 464
16.14 United States . . . . . ........................................... 465
16.15 Summary . . . . . . . . . ........................................... 468
16.16 References and further reading . ............................. 468
Index ................................................................... 474
x Contents