Potatoes postharvest

1.pdf......Page 1
7F787A7Ed01......Page 2
Contents......Page 6
Preface......Page 12
Acknowledgements......Page 14
B......Page 16
C......Page 17
H......Page 18
R......Page 19
V......Page 20
W......Page 21
1.1 Introduction......Page 22
1.2 Origin of Potatoes......Page 23
1.3 The Growing Tuber......Page 24
1.4 Factors Affecting Growth......Page 33
1.5 Physiology of Potatoes in Store......Page 38
1.6 Summary......Page 49
2.1 Harvester......Page 51
2.2 Into-store Cleaning and Separation......Page 55
2.3 Damage to the Crop......Page 61
2.5 Pesticide Application......Page 64
2.6 Transfer from Cleaner to Bulk Store Loading Elevator......Page 67
2.8 Into-store Drying Systems......Page 69
2.9 Store Loading Equipment......Page 74
2.10 Cleaning and Separating Seed Following Initial Storage and Drying......Page 75
2.11 Summary......Page 76
3.1 Microclimate Surrounding Tubers......Page 78
3.2 Benefit from Sealed, Insulated Buildings......Page 84
3.3 Purpose of Ventilation......Page 86
3.4 The Cooling Process......Page 91
3.5 Causes of Condensation......Page 97
3.6 Climate Zones......Page 109
3.7 Selection of Ventilation System Based on Climate Type......Page 111
3.8 Crop Storage Life......Page 118
3.11 Specific Requirements for Seed......Page 122
3.12 Summary......Page 123
4.1 Introduction......Page 125
4.2 Host–Disease–Environment Triangle......Page 126
4.4 Bacteria......Page 130
4.5 Fungi......Page 134
4.6 How Disease Gains Access to the Tuber Flesh......Page 143
4.8 Hygiene......Page 145
4.9 Holistic Approach......Page 150
4.10 Summary......Page 151
5.1 Low-cost Structures......Page 153
5.2 Building Structures......Page 157
5.3 Building Complexes......Page 162
5.4 Store Aspect and Exposure......Page 165
5.5 Designing for Store Hygiene......Page 166
5.6 Insulation Materials......Page 167
5.7 Building Fabric......Page 170
5.8 Floors......Page 176
5.9 Doors......Page 177
5.10 Health and Safety......Page 179
5.11 Summary......Page 183
6.2 Components of a Ventilation System......Page 185
6.3 Calculation of Airflow Rate and Backpressure in Ducted System......Page 189
6.4 Air Distribution in Bulk Stores......Page 198
6.5 Humidification of Ventilating Air......Page 209
6.6 Airspace Ventilation Systems for Boxes......Page 212
6.7 Airspace Ventilation Systems for Sacks and Big Bags......Page 217
6.8 Positively Ventilated Systems for Boxes......Page 220
6.9 Sprout Control using Chloropropham for Processing and Ware Potatoes......Page 233
6.10 Warming in the Store......Page 236
6.11 Summary......Page 237
7.1 Refrigeration Systems......Page 239
7.4 Combined Refrigeration/Ambient-air Cooling Systems......Page 244
7.5 Comparison between Direct Expansion, Two-stage Water/Glycol and Chilled-water Systems......Page 245
7.7 Sizing a Refrigeration Plant......Page 248
7.8 Summary......Page 252
8.1 Internal Store and External Air Monitoring......Page 254
8.2 Control of Crop Cooling and Cool Storage in Bulk Stores......Page 258
8.3 Control of Crop Cooling and Cool Storage in Box Stores......Page 260
8.4 Controlling Combined Ambient-air/Refrigeration Cooling......Page 262
8.5 Ensuring Uniformity of Temperatures in Store......Page 263
8.6 Control of Ventilation During Drying and Wound Healing......Page 266
8.7 Control Measures to Minimize Energy Use......Page 269
8.8 Sensors to Provide Fuller Information on Store Climate......Page 270
8.9 Sensors to Aid Store Management......Page 275
8.10 Logging Systems......Page 276
8.11 Data Storage, Use and Access......Page 278
8.12 Summary......Page 279
9.2 Store Hygiene and Equipment Inspection......Page 281
9.3 Store Preparation......Page 283
9.4 In-field Sampling......Page 289
9.5 Loading into Store......Page 290
9.6 Drying and Wound-healing Period......Page 296
9.7 Cooling......Page 300
9.8 Store Monitoring......Page 302
9.11 Reconditioning of Crops for Processing......Page 304
9.12 Warming Crops for Grading and Dispatch......Page 305
9.13 Summary......Page 307
10.1 Introduction......Page 309
10.2 Specific Requirements for Seed Storage......Page 310
10.4 Grading of Seed......Page 312
10.5 Chitting, or Pre-sprouting, of Seed......Page 328
10.6 Chitting Store for 300 t of Seed......Page 330
10.7 Communication Between Seed Producer and Customer......Page 332
10.8 Summary......Page 334
11.1 Cleaning and Sizing Prior to Packing......Page 336
11.3 Packhouse Layout......Page 338
11.4 Components of the Packhouse or Processor Intake......Page 343
11.5 Dry Cleaning Equipment......Page 346
11.6 Potato Washing Equipment......Page 349
11.8 Grader Design for Minimum Damage......Page 353
11.9 Graders or Sizers......Page 355
11.10 Inspection......Page 357
11.11 Combined Grading and Automatic Inspection......Page 359
11.12 Packaging......Page 361
11.14 Dispatch Areas and Chills......Page 367
11.15 Reject Potatoes......Page 368
11.16 Summary......Page 369
12.1 Introduction......Page 371
12.2 Quality......Page 372
12.4 Quality Assurance Schemes......Page 373
12.5 Quality Control......Page 374
12.6 HACCP Procedures......Page 375
12.7 Traceability......Page 377
12.9 Labelling Lifted Crops......Page 378
12.10 Sampling Protocols......Page 379
12.11 Sampling of Incoming Product......Page 380
12.12 Crop Assessment Prior to Dispatch......Page 386
12.13 Monitoring Crop In and Out and Waste Produced......Page 387
12.14 Critical Control Points on Inspection, Grading and Packing Line......Page 389
12.16 Accessibility to Quality Assurance System’s Information......Page 390
12.17 Summary......Page 393
13.1 Cost and Returns from Storage and Grading......Page 395
13.3 Effect of Climatic Area on Production......Page 397
13.4 Continuous Supply to the Market......Page 399
13.5 Calculating Storage and Grading Costs......Page 400
13.6 Storage Capital Costs......Page 404
13.7 Calculation of Store Variable Costs......Page 407
13.8 Calculation of Store Operating Costs......Page 409
13.19 Calculation of the Cost of Grading......Page 410
13.10 Summary......Page 411
Appendix 1: Metric–US Imperial Conversion Tables......Page 412
Appendix 2: Weather Data for World Climatic Zones......Page 415
Appendix 3: Thermal Conductivity (λ Values) for Various Building Structural Components......Page 418
Appendix 4: Theoretical Derivation of the Dimensions of Lateral Ducts used in Bulk Storage......Page 420
References......Page 428
B......Page 438
C......Page 439
D......Page 440
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H......Page 442
M......Page 443
P......Page 444
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T......Page 447
X......Page 448