食品专业英语-第三章 LESSON 3　ISSUES IN FOOD SAFETY

食品专业英语FoodProfessionalEnglish01OVERVIEWOFFOODSAFETY02FOODRAWMATERIALINGREDIENTANDNUTRITION03ISSUESINFOODSAFETY04FOODADDITIVES目录CONTENTS06FOODSAFETYTRACING07FOODSAFETYANDMICROBIALINFLUENCEFACTORS08FOODQUALITYMANAGEMENT09FOODQUALITYCONTROLANDSAFETYEVALUATION05FOODRISKANALYSISANDFOODQUALITY10CRISISMANAGEMENTFORFOODINDUSTRYLESSON3ISSUESINFOODSAFETYInrecentyears,withtherapiddevelopmentofeconomic,people'slivingstandardsarecontinuouslyimproving,moreandmorepeoplearepayingtheirattentionsonfoodsafetyissues,whichalsohavebecomeaglobalpublichealthissue.Otherwise,theglobalfoodsupplychainhaschanged,whichmeansthatourfoodonthetablecanpossiblycomefromanycornerintheworld.Therefore,therearenoboundariesforfoodsafetyissues;peoplefromallovertheworldaretryingtheirbesttosolveit.Althoughthegovernmentsofentireworldaretakingaserieseffectivemeasuretoreduceandpreventtheoccurrenceoffoodsafetyaccidents,theyhappenedfrequentlyineachyearintheworld.Foodsafetyissuesalsoreflectedthereweremanyhiddendangersintoday'sfoodproducts,themainreasonsincluding:inferiorrawmaterialsareusedinthefoodprocess,theadditionoftoxicsubstances,overuseoffoodadditives,abuseofnon-foodprocessingchemicaladditives.Atpresent,howtoprovidesafefoodforconsumersisstillamajorchallengeforsomedevelopedanddevelopingcountries,whichisalsothefocusofpolicy-makersallovertheworld.Tosolvetheproblemoffoodsafety,itisnecessarytoknowthepossiblelinksoffoodsafetyissuesoccurrenceandthefactorsthataffectfoodsafety.Atlast,theoccurrenceoffoodsafetyproblemscanbereducedoreveneliminatedbyenactinglawsandstrengtheningsupervision.Thischaptermainlyanalysesthepossiblefoodsafetyproblemsthatoccurinthewholefoodsupplychain.Itintroducestheimportantfoodsafetyaccidentsoccurredinrecentyearsallovertheworld.Theobjectivesaretomakepeopleunderstandthepossiblelinksoffoodsafetyissuesoccurrencefromplantingtotablefoodandreducetheoccurrenceoffoodsafetyissuesaspossibleaspeoplecan.Finally,somecorrespondentmeasuresareputforwardtothefoodsafetyissuesofthefoodsupplychain.Foodsafetyissuesoccurredintheentirefoodsupplychain,everylinksincludingmaterialsgrowthenvironment,climateandsoil,process,package,storage,transportationandsale,possiblecausedfoodsafetyissues.Figure1summarythepossiblefoodsafetyissuesandrisksoccurrenceinfoodsupplychain.Theseissuesandrisksarelargelyduetohumanactivities.Theypresentahighdegreeofcomplexityanduncertainty,beingrelatedtothetypeoffoodandfoodattribute,typeofsubstance,technology,region,etc.1.1FoodsafetyissuesoriginatefromtheentirefoodsupplychainFigure1summarythepossiblefoodsafetyissuesandrisksoccurrenceinfoodsupplychain2.1Environment,climateandsoilThesourcesoffoodsafetyissuesoccurrencearegrowthenvironmentoffoodprocessmaterials,climateandsoil,theeffectsofmainfactorsonenvironment,climateandsoilarenaturaldisasters,pollutionandclimate.Effectsofenvironment,climateandsoilonfoodcontaminationareshowninFigure2.Figure2Effectsofenvironment,climateandsoilonfoodcontamination2.1.1EnvironmentPollutionandbiospherefromhumanactivesareposingasteadilyrisingthreattomaintenanceoflifeintheworld.Variousenvironmentpollutionsresultedinfoodcontaminations,whichplayanultimateroleindamagingDNAhumangeneticmaterial.Humanbeingsbringenvironmentpollutionandenvironmentposesonathreatonmankindsimultaneously.Householdwaste,animalfeed,andplantfertilizersarepresentedtobeseriouscarriersforenvironmentalpollutantsandfoodcontaminants.Theeffectsoffactorsonenvironmentincludingphysicalfactorssuchasheatstress(heatwavesandcoldwaves)andirradiation;chemicalfactorssuchasplantfertilizerandtoxicsubstances;biologicalfactorssuchasmicroorganisms,parasites,insectsandworms,etc.Environmentalpollutionalsoaffectsconverselytheatmosphere,soil,water,animals,plantsandmicrobes,whichwilleventuallyresultinfoodsafetyissues.2.1.2ClimateThepotentialimpactofclimatechangeonfoodsafetyisawidelydebatedandinvestigatedissue.Theclimatechangeimpactsmycotoxinsforminplantproductsinthefieldorduringstorage.Theclimatechangealsocausesalargenumberofinsectstopropagate,thusaffectingthegrowthofplantcrops.Climatechangealsoaffectsthegrowthofweedsinthefield.Theclimatechangeleadtoalargenumberofpesticidesandinsecticidesareused,theusesofpesticideandherbicidecausepesticideresiduesaswellasharmfulchemicalsresiduesincrops.Thepathogenicbacteriapropagatequicklyfollowingmorefrequentunderextremeweatherconditions,suchasfloodingandheatwaves.However,theconsequencesofclimatechangearethetransformationforthefoodsystem,whichcomprisesallthestagesfrom“farmtofork”(mainlyprimaryproduction,processing,transportandtrading).2.1.3SoilThecropscanhardlygrowwithoutsoil,thequalityofsoilisdirectlyrelatedtothesafetyoffoodrawmaterials.Atpresent,domesticwastewateranduntreatedindustrialwastewaterarethemainpollutionsourcesofsoil.2.1.3.1PathogencontaminantsDomesticwastewater,sewagefromlivestockandpoultryfarm,leatherindustry,slaughterhouseandwastewaterfromhospitalsoftencontainvariouspathogens,suchasviruses,pathogensandparasites.Thesepathogensareretainedinsoilandtransferredfromsoiltocrops,causingfoodsafetyproblems.Thesoilcontaminatedbythepathogenscanleadmicrobiologytogrowrapidly,manyofwhicharepathogenicbacteria,insectwormsandviruses.TheyoftencoexistwithotherbacteriaandEscherichiacoli.Pathogencontaminantscantransferfromsoiltothecropsbyvariouspathways.Oncetheconditionsaresuitable,theywillcausehumanillness.2.1.3.2ToxicpollutantsToxicpollutantsrefertotheaccumulationinlivingorganismstoacertainqualitycanmakebodyfluidandtissuestakebiologicalandphysiologicalfunctionalchanges,causingatemporaryorpersistentpathologicalstate,andeventhreatenlife,suchasheavymetalsanddecomposableorganicpollutants.Thetoxicityofpollutantsiscloselyrelatedtotheamountofintake.Soiltoxicpollutantscausedbythedischargeofdomesticsewageandindustrialwastewatermainlyincluding:(1)heavymetals,Ithasbeenlongrecognizedthatheavymetalsareamongthemajorcontaminantsoffoodsupplyandmaybeconsideredasthemostimportantproblemtoourenvironment.Cropscanabsorbheavymetalsfromcontaminatedsoilandatmosphere,whichcanbeaccumulatedforalongtime.Alargeamountofheavymetalscanleadtoseriousfoodsafetyproblems.HeavymetalssuchasCdandPbhavebeenshowntohavecarcinogeniceffects,andhighconcentrationsofCu,Cd,andPbinfruitsandvegetableswererelatedtohighprevalenceofuppergastrointerestinalcancer.Heavymetalsarenoteasytodisappearinnature;theycanbeaccumulatedthroughfoodchain.Theyhavepreferentialaccumulationinhumantissues.(2)Inorganicanion,consistsofsomecarcinogenssuchasNO2-、F-andCN-anions.Thetoxiccyanideismainlyfromindustrialwastewaterdischarge,theseinorganicanionsaffecteddirectlyandindirectlycropsandresultedinfoodsafetyissues.(3)Organicpesticidesandpolychlorobiphenyls.Atpresent,therearealmost6000kindsoforganicpesticidesintheworld,andmorethan200arecommonpesticides.Pesticidesaresprayedinfarmlandandenterthesoilthroughleaching,resultinginpollution.Organicpesticidescanbedividedintoorganophosphoruspesticidesandorganochlorinepesticides.Althoughorganophosphoruspesticideshaveveryhightoxicity,theyaregenerallyeasytodegradeandpooraccumulation,andhavenoobviouseffectsonecosystem.Themajorityoforganochlorinepesticidesarehighlytoxic,hardlydegradable,highlyaccumulativeandhaveasignificantimpactontheecosystem.Cropscanalsoabsorborganicpesticidesfromcontaminatedsoilandcausepesticideresidues,whichcanleadtoseriousfoodsafetyissuesbyalong-termaccumulation.2.2AnimalsandplantsAnimalsandplantsarefoodprocessmaterials,whichgrewundertheconditionsofenvironment,climateandsoil.Theseconditionsarerelatedtothequalityoffoodprocessmaterialsandalsorelatedtofoodsafetyissues.Forplants,somechemicaltoxicsubstancesuchasheavymetals,inorganicanionsandorganicpesticides,thisresultedfoodsafetyissues.SomebiologicalsubstancessuchasMycotoxinsandPhycotoxinsalsocausetheoccurrenceoffoodsafetyissues.Thefactorsaffectedanimalsafetyincludingintheuseofantibiotics,clonedanimals,andpathogenicCampylobacterparasiticintheintestinesofmammalsandbirds.2.3Foodprocessingandpackaging

Foodmaterialsleadingtofoodsafetyissues,whichoccursfrequentlyinfoodprocessing,suchasmelamineaddition,dioxinandfoodprocessedfrominferiorrawmaterial.Foodsafetyissuesoccurrenceinfoodprocessincludingincompletephysicalremovalofcontaminants,incompleteinactivationofmicro-organisms,spores,viruses,parasites(specialrisksforthechilledstorageoffoodsofanimalorigin),incompleteinactivationofnaturalanti-nutrients,allergens,andtoxins.Nutrientsarelostbecauseofdecreaseinnutrientbioavailabilitybecauseofover-processing,formationoftoxicmolecules(acrylamide,heterocyclicamines,HMF),andenhancementofmicrobialgrowth(slicing,grinding,longstorage).Toxicchemicalsubstancesfrompackagematerialsaretransferredfrompackagematerialstofood.Thefollowingarethemainsubstancesthatmayoccurinfoodsafetyissuesduringtheprocessoffoodprocessingandpackaging.3.1Toxicsubstancesinfoodprocessandpackage3.1.1AcrylamideAcrylamide(Molecularformula:C3H5NO)possibleformedinsomecarbohydrate-richfoods,suchaspotatoesandcereal-basedproducts(potatochips,Frenchfries,bread,crisp-breads,biscuits,breakfastcereals,coffee),theseproductspossibleformedacrylamideduringcookingprocessessuchasfrying,baking,roasting,microwavingat>120°C.Acrylamidelevelswereobservedupto5mg/kginpotatochipsand2mg/kginbiscuits.Acrylamidemayalsoforminheatedfat-richdryfoodssuchasnuts.Atpresent,theexactmechanismsofformationremainunsure,butinvolveMaillardreactionsbetweenasparagineandreducingsugars/reactivecarbonyls.Acrylamideisalsoahighlyreactiveindustrialchemicalsubstanceusedfortheproductionofplasticsandmaterials.Itmaymigrateintofoodsfromsomefoodcontactmaterials.Acrylamideisaknowncarcinogentoexperimentalanimals,andmaybeareproductivetoxicant.Thelinkbetweenacrylamideandcancerriskinhumansisuncertain,althoughpeoplehavebeenexposedtoacrylamideintheirdietforalongtime.Recentstudiessuggestthattolerabledailyintakesofacrylamideforcarcinogeniclevelsshouldbesetat2.6mg/kgb.w.,Canadian,SwedishandUSstudiesestimatetheaverageexposureofadultstoacrylamideinfoodsis0.3,0.5and0.4mg/kgb.w.perday,respectively.3.1.2BisphenolABisphenolA(BPA)(4,4-dihydroxy-2,2-diphenylpropane)isused,usuallyincombinationwithotherchemicals,tomanufactureplasticsandresins.BPAisthuspresentinpolycarbonatefoodcontainerssuchasreturnablebeveragebottles,infantfeedingbottles,tableware,andstoragecontainers.BPAresiduesarealsopresentinepoxyresinsusedtomakeprotectivecoatingsforfoodandbeveragecansandvats.Duringfoodstorage,BPAmaymigrateinsmallamountsintofoodanddrinks.BisphenolAhassideeffectsonfemalegenitals.ConcerningthesafetyofBPA,EuropeanFoodSafetyAuthority(EFSA)setaTolerableDailyIntake(TDI)of50mg/kgbodyweight.EFSAnotedthatintakesofnewborninfants,childrenandadultswerewellbelowtheTDI.TherearestrongcontroversiesaboutvariouspossibletoxiceffectsofBPA.BPAispermittedinfoodcontactmaterialsintheEU,USA,Japan,butsomeUSstatesorEUcountrieshavealreadybanneditsuseforinfantfoodcontainers.3.2FraudandAdulteratedFoods

Profit-basedcriminalfraudshavecausedanumberoffoodcrisesthroughdirectorindirectadditionoftoxicsubstancestofoodsorfeeds.Thefollowingaresomefoodsafetyissuesaboutfraudandadulteratedfood:3.2.1FraudandoilsadulteratedIn2011,ditchoilaccidenthappenedinChina.Ditchoilgenerallyreferstoallkindsofinferioroilsthatexistinlife,suchasrecoverededibleoil,andrepeateduseoffriedoil.Thelargestsourceofditchoilisfromhotelandrestaurantdrainagepipesforhumanconsumption,andlongtermconsumptionmaycausecancerandgreatharmtothehumanbody.Itsmaincomponentsarestilltriglycerides,butithasmuchmorepathogenicandcarcinogenictoxinthanrealedibleoils.Therewere60,000tonditchoilrecalledfromrestaurants.3.2.2MelamineInthe2008,melaminemilkcasehappenedinChina,andabout300000infantsandyoungchildrendrankinfantmilkcontainingmelamine,whichcausedkidneyandurinarytractdiseases,withsixreporteddeaths.Investigationsshowedthatmelaminehadbeendeliberatelyaddedtodiluterawmilktoboostitsapparentproteincontent.Becausemelamineischeapandeasilyaccessible,thereisaneconomicincentiveforitsillegaladdition.ThemolecularformulaofmelamineisC3H6N6,Nitrogenlevelisveryhighinmelamine’s,accountfor66%oftotalmass.Butmelamineispresentinnonproteinaceousmolecule.Thus,theadditionofmelaminecanleadtoanincorrectlyhighproteinreading.Theacutetoxicityofmelaminewaslow,andthemedianlethaldosewas3000mg/kgbodyweightinmiceandrats.Whenthedoseincreasedupto18000mg/kgfeed,thetoxicitywasfoundtoaffecttheexcretoryorgans,kidneyandbladder,andtheseeffectsweremoreobviousinmaleorgansthaninwomen.3.2.3DioxinsDioxinsarecolorless,tasteless,fatsolublesubstanceswithserioustoxicity.In2008,RapidAlertSystemforFood&Feed(RASFF)alertnotificationsfordioxins(presentabovelegallimits)infoods.AnexampleisthatofporkfromIreland,withalargetraceandrecalloperation(from54countries)ofpigmeatandmanyprocessedporkproducts(RASFFannualreport2008).Dioxinswerefoundinpigmeatat100foldtheEUmaximumlimitof1pg/gfat.Thesourceofthiscontamination/adulterationwasasfollows.Pigsfromabout50farmswerefedwithcontaminatedbakerywastes.Thesewastesconsistedinbreadcrumbswhichhadbeendriedbydirectcontactwithcombustiongases.Andthefuelburnedtomakethecombustiongaseshadbeencontaminatedbyaddingillegallyoil.3.3FoodadditivesThemaincategoriesofadditivesarecolors,preservatives,antioxidants,emulsifiersandstabilizers,andsweeteners.Somefoodadditivesareneurotoxic,whichmeanstheyarecapableofalteringthenormalactivityofthenervoussystem–andevenkillingneurons.Theillegalproductionoffoodsandtheuseofnonauthorisedfoodorfeedadditivesarenotsinglecases.In2010,someChinesewheatflourwasadulteratedwithpulverisedlimeaddedtobleachingagent.3.4Fraud、CounterfeitedFoodsandDrinksAccordingthestatisticsin2009,thegloballeveloffraudascounterfeitinginthefoodanddrinkindustryisestimatedatabout$50bn/year.Themostfrequentlycounterfeitedfoodsanddrinksare:fruits,conservedvegetables,babyfood,milkpowder,butter,instantcoffee,spirits,drinks,confectionaries.Manycounterfeitingfoodsanddrinksobtainedhighprofitthroughdamagetofamousbrands.Foodsafetyissuesarecausedbythequalityofcounterfeitproducts.3.5‘Emerging’FoodTechnologiesSome“emerging”foodprocessingtechnologieswillalsoposeapotentialthreattofoodsafetyissues,andsometechnologiesarealsowidelyusedinthefoodindustry.Thefollowingisabriefintroductiontosomenewtechnologiesthatpossiblecausefoodsafetyissues.3.5.1‘New’physicaltreatmentsHighpressurepasteurization:incompletemicrobialinactivation,nosporeinactivation,somechemicalreactions.Pulsedelectricfields:nosporeinactivation,electrochemicalreactions;metaltransferfromelectrodes.Coldplasma:freeradicals,oxidations.LightpulsesandUV:photo-oxidativereactions.Ultrasound:incompletemicrobialandsporeinactivation.Ohmicheating:metaltransferfromelectrodes.Ionisingradiation:freeradicals,oxidativereactions.3.5.2New”chemicaltreatmentsModifiedatmosphere:candelaymicrobialgrowth,buttendtoover-extendshelf-lifeandstoragetime.Anti-microbialagents:incompletemicrobialandsporeinactivation;microbialgrowthonlydelayedinstorage,potentialtoxicity.3.6NanotechnologiesEngineerednanomaterials(ENM)ornanoparticulesarealreadyusediningredients,additives,fertilizers,pesticides,drugsandpackagingmaterials.ENMhavespecificphysico-chemicalproperties.Thefollowingisthemainusesofnanotechnologiesinfood:(1)Asfoodingredientsandadditives:increasedsolubility,dispersibility,stableemulsionswithoutemulsifier,improvedtexture;(2)Asdeliverysystemsforbioactivecompounds:protectandtargeteddeliveryofnutrients;improvetheavailabilityofbioactivecompounds.(3)Ininnovativepackaging:anti-bacterialfilms.3.7SomeAdditionalChallengesFoodsafetyissuesarefacingthecontradictionsbetweentheneedofinnovationtechnologyandfoodsafetyissues.InspiteofEFSAandfoodlaw,strictersafetyandqualitystandards,intensifiedqualitycontrolandmonitoring.Thenumberofreportedfoodsafetyincidentshasincreased,andconsumers’trustinfoodsafetyhasdecreased.Someagro-foodtechnologiestendtoelicitconsumerrejection:Ionisingirradiationoffoods;Hormonal(andantibiotic)treatmentofanimalstohastengrowthandincreasemeatormilkproduction(bannedintheEU);Variousfoodadditives;Excessiveuseofcropfertilizersandpesticides;Geneticallymodifiedfood(GMF)cropsandgeneticallymodifiedanimals.3.8ActivefoodpackageActivefoodpackagereferstowhichcansupplytheinformationofpackagedfoodpropertiesduringthecirculationandstorageperiodsbydeterminetheenvironmentconditionsofpackagedfood.Suchastime-temperatureindicator,ripenessindicator,andpackagingleakage,etc.Activefoodpackagebringsafetyrisktofoodsafetyissuesisthatmigrationofchemicalsandtheirdegradationproductsintothefood.Nanosizescouldincreaserisks.EuropeanFoodSafetyAuthority(EFSA)hasanauthorizationscheme,focusingonmigrationdataofchemicalsandtheirtoxicologicalproperties.4FoodtransportationandstorageIntheprocessoffoodtransportationandstorage,ifthemanagementofrefrigerateddistributionchannelsisimproper,foodwillbecontaminatedbysomemicroorganisms.ForsomeReady-to-EatFoods,thegrowthofListeriamonocytogenesisveryfastifpH>4.5and/orAw>0.91.Somemajoroutbreaksareassociatedwithfreshvegetablesandfruits,suchassaladgreens,lettuce,sprouts,andmelonsareleadingvehicles,withnorovirus,SalmonellaandE.coliO157asmostfrequentpathogens.5DistributionandsalesoffoodThedistributionsandsalesoffoodarethesamewiththetransportationandstorageoffoodstuffswillleadtomicrobialcontaminationiftheyarenothandledproperly.CountermeasuresagainstfoodsafetyissuesFoodsafetyissuesmayoccurinanylinkofthefoodsupplychain.Ifanylinkismonitoredandmanagedimproperly,foodsafetyissueswilloccur.Therefore,controllingandreducingtheoccurrenceoffoodsafetyisagreatchallengeforallovertheworld.Tothepossibleproblemsoffoodsafetyinfoodsupplychain,somecorrespondingcountermeasureswereputforward:1EstablishmentofreasonablefoodsafetymanagementtoolReasonablefoodsafetymanagementtoolplaysacriticalroleintheoccurrenceoffoodsafetyproblems.Thesetools,includingfoodlegislation,nationalandinternationalstandards,qualitymanagementsystems,riskanalysis,risk-basedinspectionsandcontrols,monitoringandalertsystemsforfoodcontaminantsandquantitativemicrobialriskassessment,nutritionandtoxicologystudies,andelaboratefoodprocessingtechnologieshavebroughttoconsumersandconsumershadtherighttobeinformedchoice'ofsafefoods.2Establishmentofpredictive,earlywarningandcommunicationsystemsEstablishmentofpredictive,earlywarningandcommunicationsystemscantakepreventionmeasuresbeforefoodhazardsbecomerealrisks.3SupervisionofeverylinkoffoodsupplychainFoodprocessmaterials,processtechnology,transportation,storageanddistributionneedavoidvariousbiologicalandchemicalpollutions.Asevidencedbyrecenteventsorcrises,thedioxin,acrylamide,melamine,bisphenolAcases,andthenumerouspathogenoutbreaksarestillmainreasonsofoccurrenceoffoodsafetyissues.Toreduceandeliminatefoodsafetyissues,monitoredeverylinkstrictlyinthefoodsupplychainareneeded.4EstablishmentofstrictmarketregulationsystemThemelaminestory,theinternationalandnationaltrafficofcounterfeitedfoodsanddrinksshowthatprofit-motivatedfraudandadulterationaremainthreatsoftheseincidentsoccurrence,whichneedstrictmarketregulationsystemtosupervise.5Establishmentofsafetyassessmentandpre-marketauthorizationproc