Table Of Content

Preface The7theditionofModernFoodMicrobiology,likepreviouseditions,focusesonthegeneralbiology ofthemicroorganismsthatarefoundinfoods.Allbutoneofthe31chaptershavebeenextensively revisedandupdated.Thenewmaterialinthiseditionincludesover80newbacterialand10newgenera offungi.Thistitleissuitableforuseinasecondorsubsequentcourseinamicrobiologycurriculum, orasaprimaryfoodmicrobiologycourseinafoodscienceorfoodtechnologycurriculum.Although organicchemistryisadesirableprerequisite,itisnotnecessaryforonetogetagoodgraspofmostof thetopicscovered. When used as a microbiology text, the following sequence may be used. A synopsis of the information in Chapter 1 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. ThematerialinChapter2includesasynopsisofmodernmethodscurrentlyusedtoclassifybacteria, taxonomicschemesforyeastsandmolds,andbriefinformationonthegeneraofbacteriaandfungi encounteredinfoods.Thismaterialmaybecombinedwiththeintrinsicandextrinsicparametersof growthinChapter3astheyexistinfoodproductsandastheyaffectthecommonfoodborneorganisms. Chapters4to9dealwithspecificfoodproducts,andtheymaybecoveredtotheextentdesiredwith appropriatereviewsoftherelevanttopicsinChapter3.Chapters10to12covermethodsforculturing and identifying foodborne organisms and/or their products, and these topics may be dealt with in thissequenceorjustbeforefoodbornepathogens.ThefoodprotectionmethodsinChapters13to19 includesomeinformationthatgoesbeyondtheusualscopeofasecondcourse,buttheprinciplesthat underlieeachofthesemethodsshouldbecovered. Chapters20and21dealwithfoodsanitation,indicatororganisms,HACCP,andFSOsystems;and coverageofthesetopicsissuggestedbeforedealingwiththepathogens.Chapters22to31dealwiththe known(andsuspected)foodbornepathogensincludingtheirbiologyandmethodsofcontrol.Chapter 22isintendedtoprovideanoverviewofthechaptersthatfollow.Someofitincludeswaysinwhich foodbornepathogensdifferfromnonpathogens,theirbehaviorinbiofilms,andsomeinformationon theknownrolesofsigmafactorsandquorumsensingamongfoodborneorganisms.Theothermaterial inthischapterthatdealswiththemechanismsofpathogenesisisprobablybestdealtwithwhenthe specific pathogens are covered in their respective chapters. The new Appendix section presents a simplifiedschemeforgroupingfoodborneandsomegeneralenvironmentalbacterialgenerabyuseof Gram,oxidase,andcalalasereactionsalongwithcolonypigmentation. v vi ModernFoodMicrobiology Formostsemestercourseswitha3-creditlectureandaccompanying2or3creditlaboratory,only about65-70%ofthematerialinthistextislikelytobecovered.Theremainderismeantforreference puiposes. Thefollowingindividualsassistedusbycritiquingvariouspartsorsectionsofthisedition,andwe extendspecialthankstoeach:B.P.Hedlund,K.E.Kesterson,J.Q.Shen,andH.H.Wang.Thosewho assistedwiththeprevioussixeditionsareacknowledgedintherespectiveeditions. Contents PartI—HISTORICALBACKGROUND............................................... 1 1—HistoryofMicroorganismsinFood................................................ 3 HistoricalDevelopments............................................................ 4 FoodPreservation ............................................................... 5 FoodSpoilage................................................................... 6 FoodPoisoning.................................................................. 7 FoodLegislation................................................................. 8 PartII—HABITATS,TAXONOMY,ANDGROWTHPARAMETERS................... 11 2—Taxonomy,Role,andSignificanceofMicroorganismsinFoods...................... 13 BacterialTaxonomy................................................................ 14 rRNAAnalyses.................................................................. 14 AnalysisofDNA................................................................ 15 TheProteobacteria............................................................... 15 PrimarySourcesofMicroorganismsFoundinFoods .................................. 17 SynopsisofCommonFoodborneBacteria............................................ 20 SynopsisofCommonGeneraofFoodborneMolds.................................... 27 SynopsisofCommonGeneraofFoodborneYeasts.................................... 31 3—IntrinsicandExtrinsicParametersofFoodsThatAffectMicrobialGrowth.......... 39 IntrinsicParameters................................................................ 39 pH............................................................................. 39 MoistureContent................................................................ 45 Oxidation–ReductionPotential.................................................... 49 NutrientContent................................................................. 52 AntimicrobialConstituents....................................................... 53 BiologicalStructures............................................................. 54 ExtrinsicParameters............................................................... 54 TemperatureofStorage........................................................... 54 RelativeHumidityofEnvironment................................................ 56 PresenceandConcentrationofGasesintheEnvironment............................ 56 PresenceandActivitiesofOtherMicroorganisms................................... 56 vii viii ModernFoodMicrobiology PartIII—MICROORGANISMSINFOODS ........................................... 61 4—FreshMeatsandPoultry.......................................................... 63 BiochemicalEventsThatLeadtoRigorMortis ....................................... 64 TheBiotaofMeatsandPoultry...................................................... 64 Incidence/PrevalenceofMicroorganismsinFreshRedMeats........................... 66 Bacteria........................................................................ 68 Soy-ExtendedGroundMeats ..................................................... 73 MechanicallyDebonedMeats..................................................... 74 Hot-BonedMeats................................................................ 75 OrganandVarietyMeats......................................................... 77 MicrobialSpoilageofFreshRedMeats.............................................. 78 Mechanism..................................................................... 82 SpoilageofFreshLivers............................................................ 87 Incidence/PrevalenceofMicroorganismsinFreshPoultry.............................. 88 MicrobialSpoilageofPoultry....................................................... 89 CarcassSanitizing/Washing......................................................... 91 5—ProcessedMeatsandSeafoods..................................................... 101 ProcessedMeats................................................................... 101 Curing.......................................................................... 101 Smoking........................................................................ 103 Sausage,Bacon,Bologna,andRelatedProducts....................................... 103 Spoilage........................................................................ 104 BaconandCuredHams............................................................. 108 Safety.......................................................................... 108 Seafoods.......................................................................... 109 FishandShellfish................................................................ 109 Microorganisms................................................................. 109 SpoilageofFishandShellfish....................................................... 115 Fish............................................................................ 115 Shellfish........................................................................ 118 6—VegetableandFruitProducts...................................................... 125 FreshandFrozenVegetables........................................................ 125 Spoilage........................................................................ 128 BacterialAgents................................................................. 128 FungalAgents................................................................... 134 SpoilageofFruits.................................................................. 137 Fresh-CutProduce................................................................. 138 MicrobialLoad.................................................................. 138 SeedSprouts.................................................................... 139 Pathogens....................................................................... 140 InternalizationofPathogens...................................................... 142 DiseaseOutbreaks............................................................... 143 Contents ix 7—Milk,Fermentation,andFermentedandNonfermentedDairyProducts............. 149 Fermentation...................................................................... 149 Background..................................................................... 149 DefinedandCharacterized........................................................ 150 TheLacticAcidBacteria......................................................... 150 MetabolicPathwaysandMolarGrowthYields...................................... 154 AceticAcidBacteria............................................................... 155 DairyProducts..................................................................... 156 Milk............................................................................ 156 Processing...................................................................... 157 Pasteurization................................................................... 157 GeneralMicrobiotaofMilk....................................................... 158 Milk-BornePathogens........................................................... 158 Spoilage........................................................................ 160 ProbioticsandPrebiotics ........................................................... 161 LactoseIntolerance................................................................ 162 StarterCultures,FermentedProducts................................................. 163 FermentedProducts.............................................................. 164 Cheeses......................................................................... 168 DiseasescausedbyLacticAcidBacteria............................................. 169 8—NondairyFermentedFoodsandProducts.......................................... 175 MeatProducts..................................................................... 175 FishProducts...................................................................... 178 Breads............................................................................ 179 PlantProducts..................................................................... 180 Sauerkraut...................................................................... 180 Olives.......................................................................... 180 Pickles......................................................................... 181 Beer,Ale,Wines,Cider,andDistilledSpirits......................................... 182 BeerandAle.................................................................... 182 Wines.......................................................................... 184 Cider........................................................................... 185 DistilledSpirits.................................................................. 186 MiscellaneousProducts............................................................. 188 9—MiscellaneousFoodProducts...................................................... 197 DelicatessenandRelatedFoods..................................................... 197 Eggs.............................................................................. 198 MayonnaiseandSaladDressing..................................................... 202 Cereals,Flour,andDoughProducts.................................................. 203 BakeryProducts................................................................... 203 FrozenMeatPies.................................................................. 204 Sugars,Candies,andSpices......................................................... 204 Nutmeats.......................................................................... 205 DehydratedFoods.................................................................. 206