Preface The 7th edition of Modern Food Microbiology, like previous editions, focuses on the general biology of the microorganisms that are found in foods All but one of the 31 chapters have been extensively revised and updated The new material in this edition includes over 80 new bacterial and 10 new genera of fungi This title is suitable for use in a second or subsequent course in a microbiology curriculum, or as a primary food microbiology course in a food science or food technology curriculum Although organic chemistry is a desirable prerequisite, it is not necessary for one to get a good grasp of most of the topics covered When used as a microbiology text, the following sequence may be used A synopsis of the information in Chapter will provide students with a sense of the historical developments that have shaped this discipline and how it continues to evolve Memorization of the many dates and events is not recommended since much of this information is presented again in the respective chapters The material in Chapter includes a synopsis of modern methods currently used to classify bacteria, taxonomic schemes for yeasts and molds, and brief information on the genera of bacteria and fungi encountered in foods This material may be combined with the intrinsic and extrinsic parameters of growth in Chapter as they exist in food products and as they affect the common foodborne organisms Chapters to deal with specific food products, and they may be covered to the extent desired with appropriate reviews of the relevant topics in Chapter Chapters 10 to 12 cover methods for culturing and identifying foodborne organisms and/or their products, and these topics may be dealt with in this sequence or just before foodborne pathogens The food protection methods in Chapters 13 to 19 include some information that goes beyond the usual scope of a second course, but the principles that underlie each of these methods should be covered Chapters 20 and 21 deal with food sanitation, indicator organisms, HACCP, and FSO systems; and coverage of these topics is suggested before dealing with the pathogens Chapters 22 to 31 deal with the known (and suspected) foodborne pathogens including their biology and methods of control Chapter 22 is intended to provide an overview of the chapters that follow Some of it includes ways in which foodborne pathogens differ from nonpathogens, their behavior in biofilms, and some information on the known roles of sigma factors and quorum sensing among foodborne organisms The other material in this chapter that deals with the mechanisms of pathogenesis is probably best dealt with when the specific pathogens are covered in their respective chapters The new Appendix section presents a simplified scheme for grouping foodborne and some general environmental bacterial genera by use of Gram, oxidase, and calalase reactions along with colony pigmentation v vi Modern Food Microbiology For most semester courses with a 3-credit lecture and accompanying or credit laboratory, only about 65-70% of the material in this text is likely to be covered The remainder is meant for reference puiposes The following individuals assisted us by critiquing various parts or sections of this edition, and we extend special thanks to each: B P Hedlund, K E Kesterson, J Q Shen, and H H Wang Those who assisted with the previous six editions are acknowledged in the respective editions Contents Part I—HISTORICAL BACKGROUND 1—History of Microorganisms in Food Historical Developments Food Preservation Food Spoilage Food Poisoning Food Legislation Part II—HABITATS, TAXONOMY, AND GROWTH PARAMETERS 11 2—Taxonomy, Role, and Significance of Microorganisms in Foods Bacterial Taxonomy rRNA Analyses Analysis of DNA The Proteobacteria Primary Sources of Microorganisms Found in Foods Synopsis of Common Foodborne Bacteria Synopsis of Common Genera of Foodborne Molds Synopsis of Common Genera of Foodborne Yeasts 13 14 14 15 15 17 20 27 31 3—Intrinsic and Extrinsic Parameters of Foods That Affect Microbial Growth Intrinsic Parameters pH Moisture Content Oxidation–Reduction Potential Nutrient Content Antimicrobial Constituents Biological Structures Extrinsic Parameters Temperature of Storage Relative Humidity of Environment Presence and Concentration of Gases in the Environment Presence and Activities of Other Microorganisms 39 39 39 45 49 52 53 54 54 54 56 56 56 vii viii Modern Food Microbiology Part III—MICROORGANISMS IN FOODS 61 4—Fresh Meats and Poultry Biochemical Events That Lead to Rigor Mortis The Biota of Meats and Poultry Incidence/Prevalence of Microorganisms in Fresh Red Meats Bacteria Soy-Extended Ground Meats Mechanically Deboned Meats Hot-Boned Meats Organ and Variety Meats Microbial Spoilage of Fresh Red Meats Mechanism Spoilage of Fresh Livers Incidence/Prevalence of Microorganisms in Fresh Poultry Microbial Spoilage of Poultry Carcass Sanitizing/Washing 63 64 64 66 68 73 74 75 77 78 82 87 88 89 91 5—Processed Meats and Seafoods Processed Meats Curing Smoking Sausage, Bacon, Bologna, and Related Products Spoilage Bacon and Cured Hams Safety Seafoods Fish and Shellfish Microorganisms Spoilage of Fish and Shellfish Fish Shellfish 101 101 101 103 103 104 108 108 109 109 109 115 115 118 6—Vegetable and Fruit Products Fresh and Frozen Vegetables Spoilage Bacterial Agents Fungal Agents Spoilage of Fruits Fresh-Cut Produce Microbial Load Seed Sprouts Pathogens Internalization of Pathogens Disease Outbreaks 125 125 128 128 134 137 138 138 139 140 142 143 Contents ix 7—Milk, Fermentation, and Fermented and Nonfermented Dairy Products Fermentation Background Defined and Characterized The Lactic Acid Bacteria Metabolic Pathways and Molar Growth Yields Acetic Acid Bacteria Dairy Products Milk Processing Pasteurization General Microbiota of Milk Milk-Borne Pathogens Spoilage Probiotics and Prebiotics Lactose Intolerance Starter Cultures, Fermented Products Fermented Products Cheeses Diseases caused by Lactic Acid Bacteria 149 149 149 150 150 154 155 156 156 157 157 158 158 160 161 162 163 164 168 169 8—Nondairy Fermented Foods and Products Meat Products Fish Products Breads Plant Products Sauerkraut Olives Pickles Beer, Ale, Wines, Cider, and Distilled Spirits Beer and Ale Wines Cider Distilled Spirits Miscellaneous Products 175 175 178 179 180 180 180 181 182 182 184 185 186 188 9—Miscellaneous Food Products Delicatessen and Related Foods Eggs Mayonnaise and Salad Dressing Cereals, Flour, and Dough Products Bakery Products Frozen Meat Pies Sugars, Candies, and Spices Nutmeats Dehydrated Foods 197 197 198 202 203 203 204 204 205 206 ... Dehydrated Foods 197 197 198 20 2 20 3 20 3 20 4 20 4 20 5 20 6 ... 125 125 128 128 134 137 138 138 139 140 1 42 143 Contents ix 7—Milk, Fermentation, and Fermented and Nonfermented Dairy Products Fermentation...vi Modern Food Microbiology For most semester courses with a 3-credit lecture and accompanying or credit laboratory, only about 65-70% of the material in this text is likely to be covered The