机械类文献翻译保持微创新鲜已加工果蔬的微生物和感官质量的新兴技术1文档格式.docx
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机械类文献翻译保持微创新鲜已加工果蔬的微生物和感官质量的新兴技术1文档格式.docx
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食品科学与工程(物流工程)
班级:
高地一班
姓名:
xxx
学号:
xxx
指导教师:
20**年5月
Emergingtechnologiesforkeepingmicrobialandsensoryqualityofminimallyfreshprocessedfruitsandvegetables
Theemphasisinpost-harvestfruitprotectionagainstqualityattributeslosses,physiologicaldisorders,diseasesandinsectshasshiftedfromusingagro-chemicalstovariousalternativetechniques,includingbiologicalcontrol,culturaladaptationsandphysicalmethodssuchascontrolledatmosphere(CA),MAPandirradiation.Giventherestrictionsofchemicaluseinplantfoodsandbecausemanyofthemcauseecologicalproblemsorarepotentiallyharmfultohumansandmaybewithdrawnfromuse,theadvantageofthesealternativetechniquesisthatnochemicalsareinvolved(Arté
s,1995;
GrahamandStevenson,1997;
Reddyetal.,1998;
Mathreetal.,1999;
Sanzetal.,1999;
Daugaard,2000;
Harkeretal.,2000;
Marquenieetal.,2003).Additionally,preservationtechniquesarebecomingmilderinresponsetodemandsofconsumersforhigherquality,moreconvenientfoodsthatarelessheavilyprocessedandpreservedandlessreliantonchemicalpreservatives(AbeeandWounters,1999).
Theuniquewaytoassuremicrobialandsensoryqualityofminimallyfreshprocessedplantproductsreliesonrefrigeratedstorageanddistribution,althoughcombinationofrefrigerationandsubinhibitorypreservationtechniquescouldprolongtheirshelf-life.
Asmentionedabove,manynon-conventionalmethodsarenowbeinginvestigated;
however,therearesomelimitationstotheirapplicationsincesomemethodsarenotapplicabletofresh-cutfruitsandvegetablesbecauseofdamagetoplanttissuebutonlytoliquidfoodssuchasfruitjuices(CarlinandNguyen-the,1997).Therefore,inthissectionthosetechniquesthatcanbeusedtopreservefreshprocessedplantfoodswillberevised.
Themostcriticalstepintheproductionchainofminimalfreshprocessingoffruitsandvegetablesiswashing-disinfection.Forthisreason,specialattentiontothealternativesanitizingagentsaswellasthenewtechnologiesfordisinfectionofthesecommoditieswillbegiven.Todeveloporimprovewashingandsanitizingtreatments,specialattentionshouldbepaidtothecompatibilityoftreatmentswithcommercialpractices,cost,absenceofinducedadverseeffectsonproductqualityandtheneedforregulatoryapprovalandconsumeracceptance(Sapers,2001).Somealternativestosanitizingagentsare:
O3,ClO2,peraceticacid(about90–100ppm),H2O2,organicacids(acetic,lactic,citric,malic,sorbicandpropionicacidsat300–500mg/ml),electrolysedwater,radiofrequency,hotwatertreatmentsandUV-Cradiation(Adamsetal.,1989;
Masson,1990;
Castañ
eretal.,1996;
Tomá
s-Barberá
netal.,1997;
Delaquisetal.,1999,2000,2004;
Sapers,2001;
Suslow,2002;
Jacxsens,2002;
Aguayo,2003;
Allende,2003).
1.Hydrogenperoxide
Treatmentsofhydrogenperoxide(H2O2)seemtobeapromisingalternativetochlorinefordisinfectingminimallyfreshprocessedvegetables(Soliva-FortunyandMartí
n-Belloso,2003).H2O2isgenerallyrecognizedassafe(GRAS)forsomefoodapplications,buthasnotyetbeenapprovedasanantimicrobialwash.ItdoesnotproduceresiduessinceitisrapidlydecomposedbytheenzymecatalasetowaterandO2(Sapers,2001).VariousexperimentalantimicrobialapplicationsofH2O2forfoodshavebeendescribed,includingpreservationofvegetablesalads,berriesandfresh-cutmelons(HagenmaierandBaker,1997)sinceitreducesmicrobialpopulationsandextendstheshelf-lifewithoutcausinglossofquality.SapersandSimmons(1998)recommendeditsuseforfresh-cutmelonasitextendedtheshelf-lifefor4–5daysincomparisontochlorinetreatments.However,theydemonstratedthatH2O2isinjurioustosomecommodities,causingbleachingofanthocyaninsinmechanicallydamagedberries.H2O2vapourdelayedorreducedtheseverityofbacterialsoftrotinfreshprocessedcucumber,greenbellpepperandzucchini,butnoeffectonspoilageoffresh-cutbroccoliwasfound(HagenmaierandBaker,1997).Additionally,anextendedshelf-lifewasfoundinfreshprocessedcucumbers,greenbellpeppersandzucchiniafterwashingina5–10percentsolutionofH2O2for2min(SapersandSimmons,1998).ItmeansthattheapplicabilityofH2O2toabroadrangeofminimallyfreshprocessedvegetablesshouldbedetermined,especiallywithcommoditiesthataresubjecttorapidspoilage.
2.Acidicelectrolysedwater
Thisisanewdisinfectanttechniqueforfreshproducethathasbeenshowntobeefficientduetoitsantimicrobialandantiviralactivitiesforfruitandvegetables(Izumi,1999;
KosekiandItoh,2000).Electrolysisofwatercontainingasmallamountofsodiumchloridegeneratesahighlyacidichypochlorousacidsolutioncontaining10–100ppmofavailablechlorine.Kosekietal.(2001)foundthatacidicelectrolysedwater(pH2.6,oxidationreductionpotential,1140mV;
30ppmofavailablechlorine)reducedviableaerobesinshreddedlettuceby2logcfu/gwithin10min,showingahigherdisinfectanteffectthanozonatedwater.Theyreportedthattheuseofthisnewtechniquecouldbeapplicableforfoodfactoryhygiene,meaningthattheuseofacidicelectrolysedwaterathomeorrestaurantkitchenjustbeforeeatingfreshfruitsandvegetablescouldpreventpoisoning.Accordingtothis,Parketal.(2002)reportedpopulationreductionsonlettuceleavesexceeding2.49logunitsforE.coliO157:
H7andL.monocytogenesandHortonetal.(1998)reportedpopulationreductionsofE.coliO157:
H7onapplesof3.7–4.6logunitscfu/g.However,Izumi(1999)onlyfound1logunitcfu/greductioninthemicrobialpopulationoffresh-cutvegetables.
3.Chlorinedioxide
Chlorinedioxide(ClO2)isastrongoxidizingagent(about2.5timestheoxidativecapacityofchlorine)havingabroadbiocideefficacy(Singhetal.,2002),includingagoodbiofilmpenetration.Todate,theFDA(USFDA,1998)hasallowedtheuseofaqueousClO2inwashingofuncutandunpeeledfruitandvegetables.However,ClO2isunstableanditmustbegeneratedon-siteandcanbeexplosivewhenconcentrated(Jacxsens,2002).ZhangandFarber(1996)foundthattheinitialmicrobialloaddecreasedby1logcycleofcfu/gforshreddedlettuceinoculatedwithL.monocytogenesatlevelsof5mg/lClO2inaqueoussolution.However,Reinaetal.(1995)foundthatbacterialpopulationspresentonfreshprocessedcucumberswerenotgreatlyinfluencedbyClO2treatment,evenatconcentrationof5.1mg/l.Morerecently,Singhetal.(2002)foundthatincreasingtheconcentrationofClO2indeionizedwater(5mg/lfor1and5min)resultedinadecreaseinE.coliO157:
H7populationonlettuceandbabycarrotsincomparisontowashingwithdeionizedwater(control)forthesameperiod.
Increasingthewashingperiodfrom1to15minwithaqueousClO2(5mg/l)showednosignificantreductioninthepopulationofE.coliO157:
H7onshreddedlettuce.However,afterwashingbabycarrotsareductioninE.coliO157:
H7wasfound.
4.Organicacids
Severalorganicacidshavebeentestedasalternativedisinfectantstosanitizefresh-cutvegetablesurfaces(HilgrenandSalverda,2000).Theymayretardand/orpreventthegrowthofsomemicroorganisms(Beuchat,1998).Theirantimicrobialactivityisnotgenerallyduetokillingofthecellsbuttheyaffectthecells’abilitytomaintainpHhomeostasis,disruptingsubstratetransportandinhibitingmetabolicpathways(Seymour,1999).Peraceticacidhasbeenrecommendedfortreatmentofprocesswater(HilgrenandSalverda,2000);
however,populationreductionsforaerobicbacteria,coliforms,yeastandmouldsonfresh-cutcelery,cabbageandpotatoes,treatedwith80ppmperaceticacid,werelessthan1.5logunitscfu/g(Forneyetal.,1991).Wrightetal.(2000)obtaineda2logunitscfu/greductioninappleslicesinoculatedwithE.coliO157:
H7using80ppmperaceticacid,withanintervalof30minbetweeninoculationandtreatment.
Ontheotherhand,Wisniewskyetal.(2000)foundareductionoflessthan1logunitcfu/gatthesameconcentrationbutinanintervalof24h.Citricacidhasbeenproposedasaverygoodcoadjutanttothewashingoffresh-cutfruitandvegetablesduetoitsantibrowningpower.ItisaphenolaseCu-chelatingagentandtheinhibitionofPPOwasattributedtoitschelatingaction(Jiangetal.,1999).Santerreetal.(1988)reportedthatapplicationofcitricacidcanpreventbrowningofslicedapplethusextendingshelf-lifeanditwasshownthatthecombinationofcitricacidandascorbicacidexhibitedevenmorebeneficialeffects(Pizzocaroetal.,1993).Additionally,Jiangetal.(2004)foundthattheapplicationofcitricacidwaseffectiveinextendingshelf-lifeandmaintainingthequalityoffresh-cutChinesewaterchestnutslicesduringstorage.
5.Ozone
Ozone(O3)isastrongoxidantandpotentdisinfectingagentand,whenitisappliedtofood,itleavesnoresiduessinceitdecomposesquickly.ThebiocideeffectofO3iscausedbyacombinationofitshighoxidationpotential,reactingwithorganicmaterialupto3000timesfasterthanchlorine(EPRI,1997).EventhoughitisnewfortheUSA,ithasbeenutilizedinEuropeancountriesforalongtime(Guzel-Seydimaetal.,2004).
Forinstance,ithasbeencommonlyusedasasanitizerinwatertreatmentplantssincetheearly1900s(Gomella,1972)andalsofordisinfectionofswimmingpools,sewageplants,disinfectionofbottledwaterandpreventionoffoulingofcoolingtowersinEurope(Gomella,1972;
Riceetal.,1981;
Legeron,1982;
Schneider,1982;
EcholsandMayne,1990;
Costerton,1994;
Videlaetal.,1995;
Strittmatteretal.,1996).In1997,
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- 关 键 词:
- 机械类 文献 翻译 保持 创新 加工 微生物 感官 质量 新兴 技术