Microbiology of Fruits and Vegetables

by Sapers; Gerald M.

• ISBN13: 9780849322617
• ISBN10: 0849322618
• Edition: 1st
• Format: Hardcover
• Copyright: 2005-08-29
• Publisher: CRC Press

Summary

Microbiology of Fruits and Vegetables presents a holistic view of the problem of produce contamination that examines both pre-harvest and post-harvest sources and practices. It addresses a number of topical issues relating to the microbiological quality and safety of fresh and processed fruits and vegetables and explores the linkage between microbial attachment, the state of microbial contaminants on produce surfaces, and the problem of decontamination. This volume focuses on five distinct areas, and within these areas, provides in-depth coverage of scientific issues important to an understanding of the field and technical issues of economic and public health significance.

Table of Contents

SECTION I Contamination and State of Micro flora on Fruits and Vegetables
1 Microbial Contamination of Fresh Fruits and Vegetables	3	(30)
Jim Gorny
1.1 Introduction	4	(1)
1 2 Produce Contamination	5	(2)
1.3 Microorganisms of Concern	7	(1)
1.4 Incidence and Association of Human Pathogens with Produce	8	(5)
1.4.1 FDA Imported Produce Survey	8	(1)
1.4.2 FDA Domestic Produce Survey	9	(1)
1.4.3 USDA Microbiological Data Program (MDP)	10	(2)
1.4.4 Produce-Associated Foodborne Illness Traceback Investigation Results	12	(1)
1.5 Potential Sources of Produce Contamination by Human Pathogens	13	(8)
1.5.1 Food Safety. Risk Factors Associated with Production of Fresh Produce	13	(1)
1.5.1.1 Land Use	14	(1)
1.5.1.2 Soil Amendments	14	(1)
1.5.1.3 Wild and Domestic Animal Control	14	(1)
1.5.1.4 Irrigation Water	15	(1)
1.5.1.5 Harvest Operations	15	(1)
1.5.2 Food Safety Risk Factors Associated with Postharvest Handling of Produce	16	(1)
1.5.2.1 Employee Hygiene	16	(1)
1.5.2.2 Equipment	16	(1)
1.5.2.3 Wash and Hydrocooling Water	17	(1)
1.5.2.4 Cold Storage Facilities	17	(1)
1.5.2.5 Packaging Materials	18	(1)
1.5.2.6 Modified Atmosphere Packaging of Fresh Produce	18	(1)
1.5.2.7 Refrigerated Transport, Distribution, and Cold Storage	19	(1)
1.5.3 Food Safety Risk Factors Associated with Foodservice, Restaurant, and Retail Food Stores Handling of Produce	20	(1)
1.5.4 Consumer Handling of Produce from Purchase to Plate	21	(1)
1.6 Effective Management Strategies: Contamination Prevention and Intervention	21	(4)
1.6.1 Good Agricultural Practices (GAPs)	22	(1)
1.6.2 Current Good Manufacturing Practices (cGMPs)	23	(1)
1.6.3 Hazard Analysis Critical Control Point (HACCP)	24	(1)
1.7 Research Needs	25	(2)
1.7.1 Microbial Ecology of Human Pathogens in the Agricultural Production Environment	26	(1)
1.7.2 Agricultural Water	26	(1)
1.7.3 Soil Amendments	26	(1)
1.7.4 Proximity Risk of Potential Contaminant Sources	27	(1)
1.7.5 Intervention Strategies to Reduce the Risk of Human Pathogen Contamination of Fresh Produce	27	(1)
1.8 Summary	27	(1)
References	28	(5)
2 Attachment of Microorganisms to Fresh Produce	33	(42)
Robert E. Mandrell, Lisa Gorski, and Maria T. Brandl
2.1 Introduction	34	(1)
2.2 Basic Anatomy and Biochemistry of Roots and Leaves	35	(2)
2.2.1 Rhizoplane	35	(1)
2.2.2 Phylloplane	36	(1)
2.3 Microbial Flora of Plants	37	(1)
2.4 Attachment by Plant Nitrogen Fixing, Epiphytic, and Pathogenic Bacteria to Plants	38	(10)
2.4.1 Rhizobium spp. (Rhsp)	38	(1)
2.4.1.1 Two-Step Model of Attachment	40	(1)
2.4.1.2 Attachment Factors	40	(1)
2.4.2 Agrobacterium tumefaciens (Agt)	41	(1)
2.4.2.1 Agt and Rhicadhesin	43	(1)
2.4.2.2 Pili	43	(1)
2.4.2.3 Cellulose	43	(1)
2.4.3 Ralstonia (Pseudomonas) solanacearum (Rs)	43	(1)
2.4.3.1 EPS and LPS	43	(1)
2.4.3.2 Type III Secretion System (T3SS)	44	(1)
2.4.3.3 Type II Secretion System (T2SS)	45	(1)
2.4.3.4 Rs Lectins, Fimbriae, FHA	45	(1)
2.4.4 Erwinia spp.	45	(1)
2.4.5 Pseudomonas spp.	46	(1)
2.4.6 Xanthomonas campestris (Xc)	47	(1)
2.4.7 Azospirillum spp.	48	(1)
2.4.8 Klebsiella spp.	48	(1)
2.5 Fungi and Viruses and Plants	48	(1)
2.6 Potential Attachment Factors of Enteric Bacterial Pathogens for Plants	48	(4)
2.7 Attachment of Human Enteric Pathogens to Plants and other Interactions	52	(8)
2.7.1 Lettuce and E. coli O157:H7	52	(2)
2.7.2 Tomatoes and Apples and Salmonella emerita (Se)	54	(1)
2.7.3 Sprouts and E. coli 0157 (EcO157) and Se	54	(2)
2.7.4 Cilantro and Se Thompson (SeT)	56	(1)
2.7.5 Produce Samples and L. monoutogenes (Lin)	56	(2)
2.7.6 Cantaloupe and Se, EcO157, and Lm	58	(1)
2.7.7 Arabidopsis thaliana and EcO157 and Se	58	(1)
2.7.8 Plant—Microbe Bioelms	59	(1)
2.8 Conclusions	60	(1)
Acknowledgments	61	(1)
References	61	(14)
3 Internalization and Infiltration	75	(20)
Jerry A. Bartz
3.1 Overview of Internalized Microorganisms	75	(2)
3.2 Location of Internalized Organisms in Plants	77	(1)
3.3 Structures that Enable Internalization	78	(2)
3.4 Process of Internalization	80	(1)
3.5 Internal Structures of the Plant Involved in Internalization	80	(2)
3.6 Types of Internalization	82	(5)
3.6.1 Aerosols	82	(1)
3.6.2 Water Channels and Water Congestion	82	(1)
3.6.3 Internalization in Wounds	83	(1)
3.6.4 Infiltration of the Plant Surface by Aqueous Cell Suspensions	84	(1)
3.6.5 Events in Plant Development	85	(2)
3.7 Implications and Control	87	(3)
References	90	(5)
4 Microbial Stress Adaptation and Safety of Produce	95	(22)
Luis A. Rodriguez-Romo and Ahmed E. Yousef
4.1 Microbial Stress Adaptation Phenomenon	95	(3)
4.1.1 Stress	95	(1)
4.1.2 Stress Response	96	(1)
4.1.3 Stress Adaptation and the General Stress Response	96	(1)
4.1.4 Regulation of the General Stress Response	97	(1)
4.2 Produce Microbiota as Influenced by Stress History	98	(8)
4.2.1 Preharvest Stress	98	(1)
4.2.1.1 Temperature Fluctuation	99	(1)
4.2.1.2 Ultraviolet Radiation	100	(1)
4.2.1.3 Osmotic Stress	101	(1)
4.2.2 Postharvest Stress	102	(1)
4.2.2.1 Cold Stress	102	(1)
4.2.2.2 Acid Stress	104	(1)
4.2.2.3 Oxidative Stress	105	(1)
4.2.2.4 Minimal Processing	106	(1)
4.3 Microbial Stress Adaptation on Produce	106	(1)
4.4 Assessing Stress Adaptation and Associated Risks	107	(1)
4.5 Summary	108	(1)
References	108	(9)
SECTION II Microbial Spoilage of Fruits and Vegetables
5 Bacterial Soft Rot	117	(18)
Ching-Hsing Liao
5.1 Introduction	117	(1)
5.2 Diversity of Soft-Rot Bacteria	118	(2)
5.2.1 Pectolytic Erwinia spp.	119	(1)
5.2.2 Pectolytic Fluorescent (PF) Pseudomonads	119	(1)
5.3 Factors Affecting the Survival of Soft-Rot Bacteria in Nature	120	(2)
5.3.1 Plant Vegetation	120	(1)
5.3.2 Temperature and Atmospheric Conditions	121	(1)
5.3.3 Latent Infection and Internalization	121	(1)
5.4 Enzymatic and Molecular Mechanism of Tissue Maceration by Soft-Rot Bacteria	122	(3)
5.4.1 Biochemical Characterization of Pectate Lyase (PL)	122	(1)
5.4.1.1 Analysis of PL Isozymes	122	(1)
5.4.1.2 Production of Other Pectic Enzymes	122	(1)
5.4.2 PL as the Principal Tissue-Macerating Factor	123	(1)
5.4.2.1 Transposon Mutagenesis	123	(1)
5.4.2.2 Cloning and Analysis of PL Genes	123	(1)
5.4.3 Control of PL Production and Pseudomonas Rot	123	(1)
5.4.3.1 Two-Component Regulatory Gene System	123	(1)
5.4.3.2 Role of Calcium Ions	124	(1)
5.4.3.3 Use of Ion-Chelating Agents for Control of Pseudomonas Rot	125	(1)
5.5 Interactions Between Soft-Rot and Human Pathogens on Fresh Produce	125	(2)
5.5.1 Synergistic Interactions	126	(1)
5.5.2 Antagonistic Interactions	126	(1)
5.6 Selected Farm Practices for Control of Both Soft-Rot and Human Pathogens	127	(1)
References	128	(7)
6 Microbial Spoilage of Fresh Mushrooms	135	(24)
Naveen Chikthimmah and Robert B. Beelman
6.1 Fresh Mushrooms	135	(3)
6.1.1 Introduction	135	(1)
6.1.2 Commercial Growing Practices	136	(1)
6.1.3 General Composition	137	(1)
6.2 Microbiology of Fresh Mushrooms	138	(1)
6.3 Spoilage of Fresh Mushrooms	139	(13)
6.3.1 Sources of Microorganisms Causing Spoilage	142	(1)
6.3.2 Cultural (Growing) Practices Favoring Spoilage	142	(1)
6.3.3 Cultural Practices to Suppress Spoilage of Fresh Mushrooms	142	(4)
6.3.4 Postharvest Conditions Favoring Spoilage of Fresh Mushrooms	146	(1)
6.3.5 Postharvest Practices to Suppress Spoilage of Fresh Mushrooms	147	(1)
6.3.5.1 Packaging	148	(1)
6.3.5.2 Washing Treatments	149	(1)
6.3.5.3 Irradiation	150	(1)
6.3.5.4 Pulsed Ultraviolet Light Treatment	151	(1)
6.4 Conclusions	152	(1)
References	153	(6)
7 Spoilage of Juices and Beverages by Alicyclobacillus spp.	159	(28)
Mickey E. Paris
7.1 Introduction	160	(1)
7.2 Taxonomic History	160	(4)
7.3 Physiological and Phenotypic Characteristics	164	(1)
7.3.1 Distinguishing Features	164	(1)
7.3.2 Thermoacidophilic Growth	164	(1)
7.3.3 Alicyclic Fatty Acids in Membrane	165	(1)
7.4 Thermal Resistance Characteristics	165	(7)
7.4.1 D- and z-values	165	(1)
7.4.2 Factors Affecting Thermal Resistance	166	(5)
7.4.3 Other Control Measures	171	(1)
7.5 Industrial Importance	172	(2)
7.5.1 Emergence as Spoilage Organisms	172	(1)
7.5.2 Types of Spoilage	172	(1)
7.5.3 Sanitation	173	(1)
7.6 Detection and Identification	174	(5)
7.6.1 Controversy	174	(1)
7.6.2 Media	175	(2)
7.6.3 Heat Shock Conditions	177	(1)
7.6.4 Enumeration	177	(1)
7.6.5 Detection by Enrichment	178	(1)
7.6.6 Identification and Confirmation	178	(1)
7.7 Significance of Detection/Isolation from Foods	179	(1)
7.8 Future Direction	179	(1)
Acknowledgment	180	(1)
References	180	(7)
SECTION III Food Safety Issues
8 Interventions to Ensure the Microbial Safety of Sprouts	187	(24)
William F. Fett
8.1 Introduction	187	(1)
8.2 Foodborne Illness Associated with Sprouts	188	(3)
8.3 Interventions: Seeds	191	(7)
8.3.1 Chemical and Physical	191	(6)
8.3.2 Biological	197	(1)
8.4 Interventions: Sprouts	198	(2)
8.5 Reducing the Risk of Future Outbreaks	200	(1)
8.6 Research Needs	201	(1)
Acknowledgments	202	(1)
References	202	(9)
9 Microbiological Safety of Fresh Citrus and Apple Juices	211	(20)
Susanne E. Keller and Arthur J. Miller
9.1 Introduction	211	(1)
9.2 Juice Production	212	(1)
9.3 Physicochemical Properties and Endogenous Juice Microflora	213	(3)
9.3.1 Citrus Juice	213	(1)
9.3.2 Apple Cider	214	(2)
9.4 Pathogens Associated with Fresh Juice and Their Environmental Sources	216	(3)
9.4.1 Enterohemorrhagic Escherichia coli	216	(1)
9.4.2 Salmonella Species	217	(1)
9.4.3 Cryptosporidium parvum	218	(1)
9.4.4 Listeria monocytogenes	218	(1)
9.5 Juice HACCP Rule	219	(1)
9.6 Importance of SSOPs to HACCP	219	(2)
9.7 Application of the 5-Log Standard	221	(1)
9.8 Intervention Treatments	222	(1)
9.9 Other Juice HACCP Considerations	223	(1)
9.10 Labeling	224	(1)
9.11 Conclusion	224	(1)
References	224	(7)
10 Microbiological Safety Issues of Fresh Melons	231	(1)
Dike O. Ukuku and Gerald M. Sapers
10.1 Introduction	231	(1)
10.2 Microflora of Melons	232	(2)
10.2.1 Spoilage Organisms	233	(1)
10.2.2 Human Bacterial Pathogens	233	(1)
10.3 Factors Contributing to Melon Contamination	234	(3)
10.3.1 Preharvest and Harvest Conditions	234	(1)
10.3.2 Postharvest Conditions	235	(1)
10.3.3 Mode of Microbial Attachment to Melons	236	(1)
10.4 Efficacy of Conventional Washing	237	(2)
10.4.1 Washing in the Packinghouse	237	(1)
10.4.2 Laboratory-Scale Washing Studies	237	(2)
10.5 Novel Disinfection Treatments	239	(3)
10.5.1 Hydrogen Peroxide	239	(1)
10.5.2 Hot Water	240	(1)
10.5.3 Steam	241	(1)
10.5.4 Other	242	(1)
10.6 Issues with Fresh-Cut Melons	242	(2)
10.6.1 Transfer of Bacteria from Rind to Flesh	243	(1)
10.6.2 Outgrowth on Flesh	243	(1)
10.6.3 Suppression of Outgrowth	244	(1)
10.7 Methodology for Microbiological Evaluation of Melons	244	(2)
10.8 Research Needs	246	(1)
References	247	(6)
11 Fresh-Cut Vegetables	253	(1)
Pascal Delaquis
11.1 Introduction	253	(1)
11.2 Fresh-Cut Carrots	254	(1)
11.3 Fresh-Cut Cabbage	255	(1)
11.4 Fresh-Cut Lettuce	256	(1)
11.5 Occurrence and Behavior of Human Pathogens in Fresh-Cut Vegetables	257	(2)
11.6 Interactions Between Microorganisms and Plant Tissues	259	(3)
References	262	(5)
12 Outbreaks Associated with Cyclospora and Cryptosporidium	267	(1)
Ynes R. Ortega and Charles R. Sterling
12.1 Introduction	267	(1)
12.2 Overview of the Parasites	267	(2)
12.3 Sources of Contamination	269	(1)
12.4 Description of the Foodborne Outbreaks for Both Parasites	270	(1)
12.5 Detection and Enumeration Methodologies	271	(2)
12.6 Interventions for Decontamination	273	(1)
12.7 Conclusions	274	(1)
References	275	(6)
13 Patulin	281	(1)
Lauren Jackson and Mary Ann Dombrink-Kurtzman
13.1 Introduction	282	(1)
13.2 Methods of Analysis	283	(3)
13.2.1 Introduction	283	(1)
13.2.2 Thin-Layer Chromatography (TLC)	283	(1)
13.2.3 Gas Chromatography (GC)	284	(1)
13.2.4 Liquid Chromatography (LC)	284	(1)
13.2.5 Micellar Electrokinetic Capillary Chromatography(MECC)	285	(1)
13.2.6 Other Methods	285	(1)
13.3 Toxicological Effects of Patulin	286	(2)
13.3.1 Introduction	286	(1)
13.3.2 Acute Toxicity Studies	286	(1)
13.3.3 Immunotoxicity Studies	286	(1)
13.3.4 Reproductive Toxicity and Teratogenicity Studies	287	(1)
13.3.5 Genotoxicity Studies	287	(1)
13.3.6 Carcinogenicity Studies	287	(1)
13.3.7 Mechanism(s) of Toxicity	288	(1)
13.4 Regulatory Aspects	288	(1)
13.5 Fungal Species Producing Patulin in Foods	288	(1)
13.6 Natural Occurrence of P. expansum and Patulin in Fruits and Vegetables	289	(1)
13.7 Factors Affecting Patulin Production	290	(3)
13.7.1 Introduction	290	(1)
13.7.2 Physical, Chemical, and Microbial Properties of Apples	291	(1)
13.7.3 Environmental Factors	292	(1)
13.8 Approaches for Controlling Patulin Levels	293	(7)
13.8.1 Introduction	293	(1)
13.8.2 Preharvest	294	(1)
13.8.3 Harvest	295	(1)
13.8.4 Postharvest	295	(1)
13.8.4.1 Introduction	295	(1)
13.8.4.2 Washing Treatments	296	(1)
13.8.4.3 Culling, Sorting, and Trimming	297	(1)
13.8.4.4 Chemical, Heat, and Biological Control, and Irradiation Treatments	297	(1)
13.8.4.5 Storage	299	(1)
13.8.4.6 Controls for Processed Apple Products	300	(1)
13.9 Conclusions	300	(1)
References	301	(12)
14 Safety of Minimally Processed, Acidified, and Fermented Vegetable Products	313	(1)
F. Breidt, Jr.
14.1 Introduction	314	(1)
14.2 Vegetable Microflora	314	(4)
14.2.1 Washing Procedures	316	(1)
14.2.2 Biocontrol in Minimally Processed Vegetable Products	316	(2)
14.3 Fermented Vegetables	318	(1)
14.3.1 Fermentation Chemistry	319	(1)
14.4 Acidified Vegetables	319	(3)
14.4.1 Definitions and Regulations for Acid and Acidified Foods	320	(1)
14.4.2 Pathogenic Bacteria	321	(1)
14.5 Organic Acids and Destruction of Pathogens	322	(5)
14.5.1 Specific Effects of Acids	323	(2)
14.5.2 Genetic Regulation of Acid Resistance	325	(2)
14.6 Conclusions	327	(1)
Acknowledgments	327	(1)
References	327	(12)
SECTION IV Interventions to Reduce Spoilage and Risk of Foodborne Illness
15 HACCP: A Process Control Approach for Fruit and Vegetable Safety	339	(204)
William C. Hurst
15.1 Introduction	339	(1)
15.2 What Is HACCP?	340	(2)
15.3 Applying the HACCP Concept	342	(1)
15.4 Prerequisites for HACCP	343	(1)
15.5 Planning and Conducting an HACCP Study	344	(1)
15.6 Conducting a Hazard Analysis/Risk Assessment Study (HACCP Principle 1)	345	(2)
15.7 Using SPC to Ensure HACCP Control	347	(1)
15.8 Identifying and Stabilizing Variability at CCPs (HACCP Principle 2)	348	(3)
15.9 Conducting Process Capability Analyses to Verify Critical Limits (HACCP Principle 3)	351	(3)
15.10 Establishing SPC Monitoring Procedures (HACCP Principle 4)	354	(2)
15.11 Determining Corrective Action Procedures (HACCP Principle 5)	356	(1)
15.12 Confirming HACCP Implementation Through Verification Activities (HACCP Principle 6)	357	(2)
15.13 Establishing Documentation and Record Keeping (HACCP Principle 7)	359	(2)
15.14 Summary	361	(1)
References	362	(3)
16 Effect of Quality Sorting and Culling on the Microbiological Quality of Fresh Produce	365	(1)
Susanne E. Keller
16.1 Introduction	365	(1)
16.2 Grade Standards	366	(1)
16.3 Effectiveness of Good Agricultural Practices (GAPs)	366	(1)
16.4 Effectiveness of Sorting and Sorting Methods	367	(3)
16.5 Impact on Food Safety	370	(1)
References	371	(4)
17 Washing and Sanitizing Treatments for Fruits and Vegetables	375	(1)
Gerald M. Sapers
17.1 Introduction	376	(1)
17.2 Conventional Washing Technology	376	(11)
17.2.1 Washing Agents	376	(1)
17.2.1.1 Chlorine	376	(1)
17.2.1.2 Alternatives to Chlorine	378	(5)
17.2.2 Washing Equipment	383	(1)
17.2.2.1 Types of Washers	383	(1)
17.2.2.2 Efficacy of Washers	385	(2)
17.2.3 Factors Limiting the Efficacy of Washing	387	(1)
17.3 Novel Washing Technology	387	(4)
17.3.1 Hydrogen Peroxide	387	(1)
17.3.2 Trisodium Phosphate and Other Alkaline Washing Agents	388	(1)
17.3.3 Organic Acids	389	(1)
17.3.4 Other Experimental Antimicrobial Washing Agents	390	(1)
17.3.5 Synergistic Treatment Combinations	390	(1)
17.4 Foodservice and Home Applications	391	(3)
17.4.1 FDA Recommendations	391	(1)
17.4.2 Other Options	392	(1)
17.4.3 Commercial Equipment and Wash Formulations for Home or Foodservice Use	393	(1)
17.5 Conclusions	394	(1)
Acknowledgments	394	(1)
References	394	(7)
18 Gas/Vapor-Phase Sanitation (Decontamination) Treatments	401	(1)
Richard H. Linton, Yingchang Han, Travis L. Selby, and Philip E. Nelson
18.1 Introduction	402	(1)
18.2 Chlorine Dioxide Gas	402	(12)
18.2.1 Physical, Chemical, and Safety Properties of C10, Gas	402	(2)
18.2.2 Antimicrobial Properties of Aqueous and Gaseous C102	404	(1)
18.2.3 C102 Gas Generation	404	(3)
18.2.4 General Gas/Vapor Treatment Systems	407	(2)
18.2.5 Mechanisms for Microbial Inactivation	409	(1)
18.2.6 Factors Influencing ClO2 Gas Treatment	409	(3)
18.2.7 Efficacy in Reducing Microorganisms on Different Produce Surfaces	412	(2)
18.2.8 Effects of ClO2 Gas Treatment on Quality of Produce	414	(1)
18.3 Ozone Gas	414	(8)
18.3.1 Properties of Ozone	414	(1)
18.3.2 Potential Applications of Ozone in the Food Industry	415	(1)
18.3.3 Generation of Ozone	415	(1)
18.3.4 Treatment Systems	416	(1)
18.3.5 Mechanisms of Inactivation of Microbes	417	(1)
18.3.6 Factors Influencing Sanitation Treatment by Ozone Gas	417	(1)
18.3.7 Efficacy in Reducing Foodborne Microorganisms on Produce Surfaces	418	(3)
18.3.8 Effects of Ozone Gas Treatments on Quality of Fruits and Vegetables	421	(1)
18.4 Allyl Isothiocyanate Gas	422	(1)
18.4.1 Properties	422	(1)
18.4.2 Mechanisms and Factors Influencing Sanitation Treatment	422	(1)
18.4.3 Efficacy in Reducing Foodborne Pathogens on Produce Surfaces	422	(1)
18.4.4 Effects of AITC Vapor Treatment on Quality of Fruits and Vegetables	422	(1)
18.5 Other Gases/Vapors	423	(3)
18.5.1 Hydrogen Peroxide Vapor	423	(1)
18.5.2 Acetic Acid Vapor	424	(1)
18.5.3 Other Natural Plant Volatiles	425	(1)
18.6 Present and Future Applications of Gaseous/Vapor-Phase Antimicrobials for Decontamination of Fresh Produce	426	(1)
18.7 Regulatory Considerations	427	(1)
References	428	(9)
19 Modified Atmosphere Packaging	437	(1)
B.G. Werner and J.H. Hotchkiss
19.1 Introduction	437	(2)
19.1.1 Definitions	438	(1)
19.2 Antimicrobial Activity of MAP Gases	439	(2)
19.2.1 CO2	439	(1)
19.2.2 Superatmospheric O2	440	(1)
19.3 Packaging and Films for MAP Produce Systems	441	(4)
19.3.1 Film Permeability and CO2/O2 Permselectivity	441	(1)
19.3.2 Active Packaging: Antimicrobial Films	442	(1)
19.3.2.1 Synthetic Polymer Films	442	(1)
19.3.2.2 Edible and Biodegradable Films	443	(2)
19.4 An Integrated Approach: Multiple Barriers and MAP	445	(3)
19.4.1 Background	445	(1)
19.4.2 Biopreservation and Protective Cultures	445	(2)
19.4.3 O2/CO2 Absorbers and Generators	447	(1)
19.4.4 Pretreatments and Miscellaneous Strategies	447	(1)
19.5 Microbiology of Map Fruits and Vegetables	448	(7)
19.5.1 Minimally Processed Fruits and Vegetables	448	(2)
19.5.2 Spoilage Organisms and Commodity Shelf Life	450	(1)
19.5.3 Pathogenic Organisms and Shelf Life	451	(1)
19.5.3.1 Food Safety Risk of MAP Produce	451	(1)
19.5.3.2 Psychrotrophic Pathogens	452	(1)
19.5.3.3 Other Pathogens of Concern	453	(1)
19.5.4 Microbial Ecology of MAP Systeins	454	(1)
19.6 Mathematical Predictive Modeling	455	(1)
19.7 Future Directions	456	(1)
References	456	(5)
20 Hot Water Treatments for Control of Fungal Decay on Fresh Produce	461	(1)
Elazar Fallik
20.1 Introduction	461	(2)
20.2 Technologies	463	(1)
20.3 Heat Treatments	464	(6)
20.3.1 In Vitro Studies	464	(1)
20.3.2 In Vivo Studies	465	(4)
20.3.3 Heat Damage	469	(1)
20.4 Mode of Action	470	(2)
20.5 Conclusions	472	(1)
Acknowledgments	472	(1)
References	472	(7)
21 Surface Pasteurization with Hot Water and Steam	479	(1)
Bassam A. Annous and Michael F. Kozempel
21.1 Introduction	479	(1)
21.2 Surface Pasteurization with Hot Water	480	(3)
21.3 Surface Pasteurization with Steam	483	(10)
21.3.1 Thermosafe Process	485	(1)
21.3.1.1 Process Operation	485	(1)
21.3.1.2 Process Effectiveness	485	(1)
21.3.1.3 Product Quality	486	(1)
21.3.2 University of Bristol Process	486	(1)
21.3.2.1 Process Operation	486	(1)
21.3.2.2 Process Effectiveness	486	(1)
21.3.2.3 Product Quality	487	(1)
21.3.3 Ventilex Continuous Steam Sterilizing System	487	(1)
21.3.3.1 Process Operation	487	(1)
21.3.3.2 Process Effectiveness	487	(1)
21.3.3.3 Product Quality	488	(1)
21.3.4 Vacuum—Steam—Vacuum (VSV) Process	488	(1)
21.3.4.1 Process Operation	491	(1)
21.3.4.2 Process Effectiveness	491	(1)
21.3.4.3 Product Quality	493	(1)
21.4 Conclusions	493	(1)
References	494	(3)
22 Novel Nonthermal Treatments	497	(1)
Dongsheng Guan and Dallas G. Hoover
22.1 Introduction	498	(1)
22.1.1 Nonthermal Processing Methods	498	(1)
22.1.2 Advantages and Disadvantages of Application	498	(1)
22.2 High Hydrostatic Pressure Processing (HPP)	499	(6)
22.2.1 Introduction	499	(1)
22.2.1.1 Definition and Historical Perspective	499	(1)
22.2.1.2 Equipment	500	(1)
22.2.1.3 Critical Processing Factors	500	(1)
22.2.2 Inactivation of Problematic Microorganisms	501	(1)
22.2.2.1 Spores and Vegetative Bacteria	501	(1)
22.2.2.2 Viruses	504	(1)
22.2.2.3 Parasites	505	(1)
22.2.3 Summary	505	(1)
22.3 Irradiation	505	(4)
22.3.1 Introduction	505	(1)
22.3.2 Application to Fruits, Vegetables, and Juices	506	(1)
22.3.2.1 Spores and Vegetative Bacteria	506	(1)
22.3.2.2 Parasites	508	(1)
22.3.2.3 Viruses	508	(1)
22.3.3 Summary	509	(1)
22.4 Pulsed Electric Fields in Juice Processing	509	(3)
22.4.1 Introduction	509	(2)
22.4.2 Application to Juices	511	(1)
22.4.3 Summary	512	(1)
22.5 Ultrasonic Waves for Preservation of Fruit and Vegetable Products	512	(2)
22.5.1 Introduction and Description of Process	512	(1)
22.5.2 Microbial Inactivation	513	(1)
22.5.3 Summary	514	(1)
22.6 Electrolyzed Water	514	(2)
22.6.1 Introduction	514	(1)
22.6.2 Application as a Novel Disinfectant for Fruits and Vegetables	515	(1)
22.6.3 Summary	516	(1)
22.7 Final Remarks and Future Perspectives	516	(1)
Acknowledgment	517	(1)
References	517	(6)
23 Biological Control of Microbial Spoilage of Fresh Produce	523	(1)
Julien Mercier and Pamela G. Marrone
23.1 Introduction	523	(1)
23.2 Approaches to Biocontrol in Postharvest Situations	524	(4)
23.2.1 Use of Naturally Occurring Antagonists for Colonization of Infection Sites	524	(1)
23.2.1.1 Postharvest Applications	524	(1)
23.2.1.2 Preharvest Applications	525	(1)
23.2.1.3 Possible Mechanisms for Biocontrol	526	(1)
23.2.2 Use of Mutant Pathogen Strains	527	(1)
23.2.3 Biological Fumigation	528	(1)
23.3 Advantages and Limitations of Postharvest Biocontrol	528	(2)
23.3.1 Advantages of Postharvest Biocontrol	528	(1)
23.3.2 Disadvantages of Biocontrol Agents	529	(1)
23.4 Enhancing Biocontrol Activity	530	(3)
23.4.1 In Combination with Other Treatments	530	(1)
23.4.2 Improvement in Formulation	531	(1)
23.4.3 Screening and Selection of the Microorganism	532	(1)
23.4.4 Collaborative Research Among Industry, University Researchers, Government, and Growers/Packers	532	(1)
23.5 Regulatory Process for Biocontrol Agents	533	(1)
23.5.1 U.S. Environmental Protection Agency (EPA)	533	(1)
23.5.2 California and International Regulations	534	(1)
23.6 Concluding Remarks	534	(1)
References	535	(8)
SECTION V Microbiological Evaluation of Fruits and Vegetables
24 Sampling, Detection, and Enumeration of Pathogenic and Spoilage Microorganisms	543	(78)
Larry R. Beuchat
24.1 Introduction	543	(2)
24.2 Pathogen or Spoilage Microorganism Under Study	545	(6)
24.2.1 Media for Routine Microbiological Analyses	546	(2)
24.2.2 Selection of Test Strains for Sanitizes Efficacy and Challenge Studies	548	(3)
24.3 Types of Produce and Methods for Preparing Samples	551	(5)
24.4 Procedures for Inoculation	556	(1)
24.5 Efficiency of Retrieval	557	(1)
24.6 Efficacy of Decontamination Treatment	558	(1)
24.7 Procedures for Detection and Enumeration	558	(1)
24.8 Number of Samples Analyzed and Reporting the Results	559	(2)
References	561	(4)
25 Rapid Detection of Microbial Contaminants	565	(1)
Daniel Y.C. Fung
25.1 Introduction	565	(1)
25.2 Sample Preparation and Treatments	566	(1)
25.3 Total Viable Cell Count Methodologies	567	(5)
25.4 Advances in Miniaturization and Diagnostic Kits	572	(3)
25.5 Immunological Testing	575	(4)
25.6 Instrumentation and Biomass Measurements	579	(4)
25.7 Genetic Testing	583	(5)
25.8 Biosensors	588	(2)
25.9 U.S., World Market, and Testing Trends (1999-2008)	590	(2)
25.10 Predictions of the Future	592	(1)
Acknowledgment	593	(1)
References	593	(2)
26 Methods in Microscopy for the Visualization of Bacteria and Their Behavior on Plants	595	(1)
Maria T. Brandl and J.-M. Monier
26.1 Introduction	596	(1)
26.2 Visualization of Bacteria on Plants: Available Tools	596	(4)
26.2.1 Labeling of Bacteria with Fluorescent Proteins	596	(2)
26.2.2 Labeling of Bacteria with Dyes and Fluorescent Conjugates	598	(2)
26.3 Applications	600	(12)
26.3.1 Spatial Distribution	600	(2)
26.3.2 Cell—Cell Interactions	602	(2)
26.3.3 Measurement of Biological Parameters	604	(1)
26.3.3.1 Kogure Assay for Cell Viability	605	(1)
26.3.3.2 Indicators of Membrane Integrity	606	(1)
26.3.3.3 GFP Fluorescence and Cell Viability	607	(1)
26.3.3.4 Other Fluorescent Indicators of Bacterial Physiology	607	(1)
26.3.4 Bacterial Gene Expression In Situ on Plants	608	(1)
26.3.4.1 GFP as a Reporter of Gene Expression	608	(1)
26.3.4.2 Practical Note on the Use of GFP for Gene Expression Measurements	610	(1)
26.3.4.3 FISH for the Detection of Bacterial mRNA	611	(1)
26.3.4.4 Immunolabeling of Gene Products	611	(1)
26.4 Other Types of Microscopy	612	(2)
26.4.1 Multiphoton Excitation Fluorescence Microscopy	612	(1)
26.4.2 Fluorescence Stereomicroscopy	613	(1)
26.4.3 Immunoelectron Microscopy	613	(1)
26.5 Concluding Remarks	614	(1)
References	615	(6)
Index	621