Active film from chitosan incorporating green tea extract for shelf life extension of pork sausages
上传者:赖翔飞|上传时间:2015-05-11|密次下载
Active film from chitosan incorporating green tea extract for shelf life extension of pork sausages
FoodHydrocolloids27(2012)102e108
ContentslistsavailableatSciVerseScienceDirect
FoodHydrocolloids
journalhomepage:http://wendang.chazidian.com/locate/fo
内容需要下载文档才能查看odhyd
Active?lmfromchitosanincorporatinggreenteaextractforshelflifeextensionofporksausages
UbonratSiripatrawan*,SuparatNoipha
DepartmentofFoodTechnology,FacultyofScience,ChulalongkornUniversity,Patumwan,Bangkok10330,Thailand
articleinfo
Articlehistory:
Received15February2011Accepted18August2011Keywords:
ActivepackagingChitosan?lm
GreenteapolyphenolsShelflife
AntimicrobialAntioxidant
abstract
Chitosan?lmincorporatinggreenteaextract(CGT-?lm)wasusedasactivepackagingforshelflifeextensionofporksausages.Thephysical,chemical,microbiological,andsensoryqualitiesofporksausageswrappedwithCGT-?lmwerecomparedwiththosewrappedwithchitosan-alone?lm(C-?lm)andthosewithoutchitosan?lmwrapping(control).Changesinthequalitiesofporksausagesincludingcolor,texture,lipidoxidationwithrespecttothiobarbituricvalue(TBA),andmicrobiologicalqualitiesincludingtotalplatecounts,yeastsandmolds,andlacticacidbacteriaweredeterminedthroughoutthestorageat4??C.Thesensoryqualitiesincludingodor,color,slimeformation,andoverallacceptabilitywereevaluatedusingQuantitativeDescriptiveAnalysis.ItwasfoundthatsampleswrappedwithCGT-?lmshowedlowerchangesincolor,texture,TBAvalue,microbialgrowth,andsensorycharacteristicsthanthosewrappedwithC-?lmandcontrol,respectively.Successfulinhibitionoflipidoxidationandmicrobialgrowthintherefrigeratedporksausageswaspossiblewithchitosan?lmincorporatinggreenteaextract.Theresultssuggestedthatincorporationofgreenteaextractintochitosan?lmcouldenhancetheantioxidantandantimicrobialpropertiesofthe?lmandthusmaintainedthequalitiesandprolongedtheshelflifeofthesausages.
Ó2011ElsevierLtd.Allrightsreserved.
1.Introduction
Activepackaging,thenewgenerationoffoodpackaging,isgaininginterestfromresearchersandindustryduetoitspotentialtoprovidefoodqualityandsafetybene?ts.Duetotheconsumerconcernsaboutfood-relatedhealthrisksandenvironmentalproblems,currentresearchinactivepackaginghasfocusedontheuseofnaturalpreservativesinbiodegradablepackagingmaterials(Suppakul,Miltz,Sonneveld,&Bigger,2003;Yingyuadetal.,2006).Favorableactivepackagingsystemsarebasedontheincorporationofnaturalantimicrobialand/orantioxidativesubstancesinfoodpackagingmaterialsinordertocontrolundesirablechangesoffoodqualities(Dutta,Tripathi,Mehrotra,&Dutta,2009;Fernandez-Saiz,Lagaron,&Ocio,2009;Salgado,Fernández,Drago,&Mauri,2011).
Chitosan,alinearpolysaccharideofrandomlydistributedb-(1-4)-linkedD-glucosamineandN-acetyl-D-glucosamine,isafunctionalbiopolymerobtainedfromdeacetylationofchitin.Chitosanisnon-toxic,biocompatible,andbiodegradableandthusisconsideredasanenvironmentallyfriendlypackagingmaterial(Caner&Cansiz,2007;Caner&Cansiz,2008;Fernandez-Saizetal.,2009;Pereda,
*Correspondingauthor.Tel.:þ6622185536;fax:þ6622544314.E-mailaddress:ubonratana.s@chula.ac.th(U.
内容需要下载文档才能查看Siripatrawan).0268-005X/$eseefrontmatterÓ2011ElsevierLtd.Allrightsreserved.doi:10.1016/j.foodhyd.2011.08.011
Ponce,Marcovich,Ruseckaite,&Martucci,2011).Chitosanhasbeenusedasantimicrobial?lmsandcoatingsduetoitseffectivenessofinhibitingthegrowthofnotonlyGram-positiveandGram-negativebacteriabutalsoyeastsandmolds(Chen,Yeh,&Chiang,1996).Chitosanantimicrobialactivitycomesfromitspositivechargesthatwouldinterferewiththenegativelychargedresiduesofmacromol-eculesonthemicrobialcellsurface,causingthemembraneleakage(Duttaetal.,2009;Peredaetal.,2011).Duetoitsintrinsicantimi-crobialpropertiesandgood?lm-formingability,chitosancanbeusedasactiveantimicrobial?lms(Fanetal.,2009;Hernández-Muñoz,Almenar,Valle,DelVelez,&Gavara,2008).
Incorporationofantimicrobialand/orantioxidativesubstancesintopackagingmaterialshasbecomepopularsincemicrobialspoilageandoxidationaremajorproblemsaffectingfoodquality.Thisapproachcanreducetheadditionoflargeamountsoffoodadditivesthatareusuallyincorporatedintofood.Duetothepotentialhealthriskscausedbysyntheticactivecompounds(Gómez-Estaca,Gimnez,Montero,&Gómez-Guillén,2009),extensiveresearchhasbeenconductedtoemploysomenaturalactivecompoundsasalternativestosyntheticantioxidants,includingincorporationofa-tocopherolinto?shskingelatin?lms(Jongjareonrak,Benjakul,Visessaguan,&Tanaka,2008),additionoftetrahydrocurcuminoidsintochitosan?lms(Portes,Gardrate,Castellan,&Coma,2009)anduseofantioxi-dantborageextractingelatin?lms(Gómez-Estacaetal.,2009).
U.Siripatrawan,S.Noipha/FoodHydrocolloids27(2012)102e108103
Greentea(Camelliasinensis)isagoodsourceofpolyphenoliccompounds(Chan,Lim,&Chew,2007).Catechins(alsoknownas?avanols),includingepicatechin(EC),epigallocatechin(EGC),epi-catechingallate(ECG),epigallocatechingallate(EGCG),catechin(C),gallocatechingallate(GCG),catechingallate(CG),andgalloca-techin(GC),arethedominantphenoliccompoundsintealeaves.Besides?avanols,various?avonols,suchasquercetin,kaempferol,andquercetagetin,and?avones,suchasrutinandchrysin,arealsopresentintealeaves(Chanetal.,2007;Yilmaz,2006).Greenteapolyphenolshavebeenreportedtoactasfreeradicalscavengerstoterminatetheradicalchainreactionsthatoccurduringtheoxida-tionoftriglyceridesinfoodsystems(Bozkurt,2006;Perumalla&Hettiarachchy,2011),andhasshowninhibitoryeffectsinvitroagainstfoodspoilageandpathogenicmicroorganismsincludingListeriamonocytogenes,EscherichiacoliO157:H7,Salmonellatyphi-murium,Staphylococcusaureus,Shigella?exneri,andVibriocholerae(Hamilton-Miller,1995;Perumalla&Hettiarachchy,2011).
Cookedporksausage,aready-to-eatmeatproductwidelyconsumedinThailand,ispronetospoilagebybothmicrobialcontaminationandlipidoxidation,causingfoodbornediseasesandunacceptableorganolepticcharacteristics.Therefore,preventingbacterialgrowthanddelayinglipidoxidationcanpromotetheextensionofshelflife.Ourpreviousstudyhasshownthataprom-isingactivechitosan-based?lmcouldbeachievedbyincorporationwithgreenteaextract,asanaturalactiveagent,toimproveitsantimicrobialandantioxidantproperties(Siripatrawan&Harte,2010).Therefore,thisresearchwasaimedtodeterminethefeasi-bilityofusingthedevelopedchitosan?lmincorporatinggreenteaextractasactivepackagingtoextendshelflifeofporksausages.2.Materials&methods2.1.Materials
Commercialfoodgradechitosanwithamolecularweightof100kDaanddeacetylationdegreeof95%waspurchasedfromSeafreshIndustryPublicCompanyLimited(Chumphon,http://wendang.chazidian.commercialgreentealeaveswerepurchasedfromalocalhyper-marketinBangkok.Greenteaaqueousextractsolutionwaspreparedbymixinggroundteaindistilledwater(1:5w/v),controlledat90??Candshakenat100oscillation/minfor10min.Polyphenoliccompoundsinthegreenteaaqueousextract(Fig.1)weredeterminedusinghighperformanceliquidchromatography(HPLC),equippedwitha5mm,250Â4.6mmidC18separationcolumnandaphotodiodearraydetector(VarianInc.Scienti?cInstruments,PaloAlto,USA)followingthemethodofSiripatrawan,Pongamphai,Douglas,andHarte(2008).PlateCountAgar,PotatoDextroseAgar,andLactobacillusMRSAgarwereobtainedfromHiMediaLaboratoriesPvt.Limited(Bombay,India).Hydrochloricacid,2-thiobarbituricacid,aceticacid,andglycerolwereobtainedfromSigmaeAldrich(SigmaChemicalCo.,St.Louis,MO,USA).2.2.Filmpreparation
Chitosan?lm-formingsolution(2%w/v)waspreparedaccordingtotheprocedureofSiripatrawanandHarte(2010)bydissolvingspeci?camountofchitosanpowderinto1%aceticacidsolutionandglycerolattheconcentrationof30%w/wofchitosanpowderwasusedasplasticizer.Thegreenteaaqueousextractsolutionwasthenmixedwithchitosansolutiontoobtainthe?nalconcentrationsof20%(w/v)ofgreenteainthechitosan?lm-formingsolution.Theresultingsolutionwashomogenizedusingahomogenizer(D-79282,YstralGmbH,Ballrechten-Dottingen,Germany)andwassubsequentlydegassedtoremoveairbubblesusingasonicator(UltrasonicProcessor,Cole-Parmer,VernonHills,Illinois,USA).Each?lm-forming
Fig.1.HPLCchromatogramofaqueousgreenteaextract:1,gallicacid;2,EGC;3,catechin;4,EGCG;5,EC;6,rutin;7,ECG;8,quercetin;9,kaempferol.
solution(90g)wascastona12Â28.5cm2ceramicplateanddriedatambienttemperature(26??C).Theobtained?lmswereconditionedinanenvironmentalchamberat25??Cand50%relativehumidity(RH)for48hbeforeused.2.3.Samplepreparation
Cookedporksausageswereobtainedfromalocalmeatpro-cessingplantontheinitialdayofmanufacture.Thesausagescon-tained61.43Æ0.93%moisture,18.94Æ0.86%fat,16.26Æ0.78%protein,and2.12Æ0.31%ash.Chitosan-alone?lm(C-?lm)andchitosan?lmcontaininggreenteaextract(CGT-?lm)wereusedtowraparoundthesausages.Thesampleswithoutchitosan?lmwrappingwereusedascontrol.Eachsamplewasindividuallypackagedintoa8Â12cmpouchof85mmlinearlowdensitypolyethylenecoatedwithpolyamideplasticbagunderatmosphericconditionsandheat-sealedusinganimpulsesealer.Allsampleswerestoredat4Æ1??Candwereanalyzedondays0,4,8,12,16,and20(onlyCGT-?lmwrappedsampleswerestoreduptoday24).Thesausagesampleswereanalyzedimmediatelyafteropeningthepackagesandremovingthewrappedchitosan?lms.Allmeasure-mentswereconductedonthreeseparatesamplesinduplicate.2.4.Microbiologicalanalysis
Twenty?vegramsofporksausageswerehomogenizedin225mlof0.1%peptonebufferfor2minusingaStomacherLabBlender(SewardLaboratory,London,UK).Serialdecimaldilutionsweremadewiththesamediluent.Thesampleswerespread-platedonPlateCountAgarandincubatedat37??Cfor24hfortotalviablecounts.Foryeastsandmolds,thesampleswerespread-platedonPotatoDextroseAgarandincubatedat25??Cfor72h.Forlacticacidbacteria,thesampleswerepour-platedonLactobacillusMRSAgarandincubatedat37??Cfor72h,followingthemethodofBingolandBostan(2007).2.5.Lipidoxidation
Thiobarbituricacid(TBA)measurementwasdeterminedfollowingthemethodofTarladgis,Watts,andYounathan(1960).Tengramsofhomogenizedsamplewereaddedwith97.5mlofdistillatedwaterand2.5mlof4NHCl.Themixturewasheatedwithsteamdistillation.Fivemlofdistillatewasaddedto5ml
内容需要下载文档才能查看of
104U.Siripatrawan,S.Noipha/FoodHydrocolloids27(2012)102e108
thiobarbituricreactivereagentcontaining0.02MTBAin90%glacialaceticacidandincubatedinboilingwaterfor35min.Aftercooling,theabsorbanceofthepinksolutionwasmeasuredat538nmusingaspectrophotometer(ThermoScienti?cGENESYS20,ThermoFisherScienti?c,Inc.,Rochester,NY,USA).Theconstant7.8wasusedtocalculatetheTBAnumberusingEq.(1).TheTBAvalueisexpressedasmilligramsofmalonaldehydeperkgofsample.
TBAvalue¼7:8Abs538
(1)
2.6.Colormeasurement
CIELABcolor(L*,a*,b*)valuesweremeasuredusingaMinoltaChromameter(CR-300,MinoltaCameraCo.,Japan)witha10mmdiameterapertureanda10??standardobserver.ThevaluesforL*(lightness),a*(redness),andb*(yellowness)wererecordedtoevaluatesurfacecolorchangesofporksausagesduringstorage.2.7.Texturemeasurement
Thetexture(cuttingforce)wasmeasuredusingaTextureanalyzer(LloydFoodTextureAnalyzer,modelTA500,England)withadisplacementspeedof2mm/s(Rao&Henrickson,1983).Theforcenecessarytoobtainaconstantdeformationof30mmwasrecordedingramforce.2.8.Sensoryevaluation
Thesampleswereevaluatedbyanexperiencedten-memberpanel.Panelistswerechosenonthebasisofpreviousexperienceinconsumingporksausages.Furthermore,apreparatorysessionwasheldpriortotestingsothateachpanelmembercouldthor-oughlydiscussandclarifyeachattributetobeevaluated.Testingwasinitiatedafterthepanelistsagreedonthespeci?cations.Thesausageswerebroughttoapproximately25??Cbeforeassessment.QuantitativeDescriptiveAnalysiswasusedtoobtainfourattributestodescribethesamples.Odorattributeswereassessed?rst,fol-lowedbyappearance(colorandslime)andoverallacceptability.Thesensoryevaluationwasclassi?edintotenstages:odor(9¼extremelydesirable;5¼slightoff-odor;0¼extremelyunac-ceptable);discoloration(0¼nodiscoloration;5¼slightdiscolor-ation;9¼extremelyunacceptable),slimeformation(0¼noslimeformation;5¼slightslimeformation;9¼extremelyunaccept-able),andoverallacceptability(9¼extremelydesirable;5¼slightlyunacceptable;0¼extremelyunacceptable).2.9.Statisticalanalysis
SymmetricFactorialExperimentwithCompletelyRandomizedDesign(CRD)wasusedforcolor,texture,andTBAmeasurementsoverthestorageperiod.RandomizedCompleteBlockDesignwasusedforassessmentofsensoryevaluation.Thestatisticalsigni?-canceofdifferencesbetweenmeanvalueswasestablishedatp 0.05withtheDuncan’sNewMultipleRangeTestinthegeneralmodeloftheSPSSstatisticalpackage(SPSSInc.,Chicago,Illinois).3.Resultsanddiscussion3.1.Microbiologicalanalysis
Table1isshowntotalcounts,yeastsandmolds,andlacticacidbacteriaofporksausagesduringstorageat4??C.Controlsausagesampleswerefoundtohavehigherpopulationoftotalaerobiccounts,yeastsandmolds,andlacticacidbacteria.These
Table1
Totalcount,yeastsandmolds,andlacticacidbacteria(LogCFU/g)aofporksausagesduringstorageat4??C.StorageSamplesTotalcountYeastsandLacticacidtime(days)moldsbacteria0
Control<1NDNDC-?lm<1NDNDCGT-?lm<1
NDND4
Control2.55Æ0.03eND<1C-?lm<1NDNDCGT-?lm<1
NDND8
Control2.62Æ0.06e<1<1C-?lm<1<1<1CGT-?lm<1
<1
ND
12
Control5.24Æ0.18c3.57Æ0.10d2.52Æ0.07cC-?lm1.11Æ0.16f1.01Æ0.11f<1CGT-?lm<1
<1
<1
16
Control6.54Æ0.02b4.35Æ0.10c3.03Æ0.04bC-?lm2.27Æ0.36e2.84Æ0.14e<1CGT-?lm1.14Æ0.21f1.24Æ0.28f<1
20
Control9.01Æ0.15a6.72Æ0.02a3.66Æ0.10aC-?lm3.64Æ0.17d5.04Æ0.08b1.25Æ0.26dCGT-?lm
2.52Æ0.09e
3.17Æ0.23e
1.02Æ0.21d
ND¼notdetected.aef
Meanswithincolumnshavingthesamesuperscriptdonotdiffersigni?cantly(p>0.05).a
DatarepresentmeanÆstandarddeviationofthreereplications.
microorganismsareconsideredasspoilagemicro?http://wendang.chazidian.comcticacidbacteriaareidenti?edasspoilagebacteriaofsausagesandotherprocessedmeatsstoredatrefrigeratedtemperatures(Ambrosiadis,Soultos,Abrahim,&Bloukas,2004;Yingyuadetal.,http://wendang.chazidian.comcticacidbacteriamaycausesouring,slimyand/orgreeningandcanproducelacticacid,ethanolandshort-chainfattyacidswhichcontributetooff-odors(Samelis,Kakouri,&Rememtzis,2000).Thepopulationofyeastsandmoldswasalsorelativelyhigh,whichmaycausetheslimeformationonthesausagesurface.Themicrobialgrowthwasmorerapidinthecontrolsampleswherethetotalviablecountof5.24LogCFU/gwasfoundonday12.Atthispoint,thecontrolsampleshadoff-odoranddiscolorationandwouldhavebeenrejectedbytheconsumers.
Whencomparedwithcontrolsamples,sampleswrappedwithC-?lmhadlowervariabilityoftotalaerobiccounts,yeastsandmolds,andlacticacidbacteria.Thisresultsuggestedthatchitosan?lmcouldinhibitmicrobialgrowthinthesausages.Theantimi-crobialeffectofchitosanisthoughttoberelatedtoelectrostaticinteractionbetweenapositivechargeontheNHþ3groupofglucosaminemonomerinchitosanmoleculesandnegativechargeofmicrobialcellmembranethatleadstotheleakageofintracellularconstituents(Duttaetal.,2009).Incorporationofchitosan?lmwithgreenteaextractenhancedtheantimicrobialpropertiesofthe?lm,astotalaerobiccounts,yeasts,andmoldsinthesausageswrappedwithCGT-?lmwerelowerthanthosewrappedwithC-?lm.Theeffectwasparticularlyevidentonday12andthereafter.However,nosigni?cantdifferenceforlacticacidbacteriacountswasobservedbetweensampleswrappedwithC-?lmandCGT-?lm.TheenhancedantimicrobialactivityofCGT-?lmispotentiallyattributedtogreenteapolyphenolswhicharecapableofbacteri-cidalactivity(Yilmaz,2006),byinhibitionofDNAandRNAsynthesisofbacterialcells(Mori,Nishino,Enoki,&Tawata,1987),inhibitionofcytoplasmicmembranefunctionofbacteria(Tsuchiya,Sato,&Iinuma,1994),andinterferingwithenergymetabolismsofbacteria(Haraguchi,Tanimoto,Tamura,Mizutani,&Kinoshita,
U.Siripatrawan,S.Noipha/FoodHydrocolloids27(2012)102e108105
1998).TheresultsaresupportedbythoseofWuetal.(2007)whofoundthatepicatechinandcaffeineingreenteacouldinhibitS.aureus,Bacillussubtilis,andE.coli,aswellasHamilton-Miller(1995)whoreportedthatphenoliccompoundsingreenteacouldinhibitE.coli,S.typhimurium,L.monocytogenes,S.aureus,andCampylobacterjejuni.Yam,Shah,andHamilton-Miller(1997)sug-gestedthattheantibacterialactivityofgreenteaextractscanbeexplainedbyitscontentofEGCG,ECG,GC,andEGC.Moreover,quercetinandkaempferolshowedactivityagainstgram-positivebacteriaandphytopathogenicfungi(Hamilton-Miller,1995).3.2.Lipidoxidation
Lipidoxidation,withrespecttoTBAvaluesofcontrolsausagesamplesandthosewrappedwithC-?lmandCGT-?lmisshowninFig.2.Duringthestorage,signi?cantlyhigher(p 0.05)TBAwasevidentincontrolsamplesthanthosewrappedwithC-?lmandCGT-?lm,respectively.Thisresultsuggestedthatlipidoxidationinsausagesamplescouldbeminimizedbytheuseofchitosan?lmprobablyduetotheantioxidantactivityofchitosan(Park,Je,&Kim,2004)aswellasitslowoxygenpermeabilitycharacteristic(Xu,Kim,Hanna,&Nag,2005).TheantioxidantabilityofC-?lmisthoughttobeduetochelationoffreeionwhichisreleasedfromhemoproteinsofmeatduringstorage(Shahidi,Arachchi,&Jeon,1999).
Incorporationofgreenteaintochitosan?lmenhancedtheantioxidantpropertiesofthe?lm,asTBAvaluesofCGT-?lmwrappedsampleswerelowerthanthosewrappedwithC-?lm.Teaextractsarepowerfulantioxidants,mainlyowingtothepres-enceofC,EC,EGC,ECG,EGCG,GCG,CG,andGC,whichareeffectivefreeradicalscavengersandmetalchelation(Chanetal.,2007;Farhoosh,Golmovahhed,&Khodaparast,2007).Theantioxidantactivitiesoftheinferredgreenteapolyphenolshavebeenattrib-utedtoassortedmechanisms,includingpreventionofradicalchaininitiation,bindingoftransitionmetalioncatalysts,andinteractionwiththefreeradicalstoinhibitlipidoxidation(Farhooshetal.,2007;Perumalla&Hettiarachchy,2011).3.3.Color
ColorvaluesincludingL*coordinate(lightnessindicator),a*value(indicatorofthetendencytowardtheredfora*positiveorgreenfora*negative)andb*value(indicatorofthetendencytowardyellowforb*positiveorblueforb*negative)ofcontrolporksausagesamplesandthosewrappedwithC-?lmandCGT-?lmduringstorageat4??CareshowninFig.3.
Fig.2.TBAvaluesofcontrolporksausagesamplesandthosewrappedwithC-?lmandCGT-?lmduringstorageat4??C.ValuesaregivenasmeanÆstandard
内容需要下载文档才能查看deviation.
Controlsamplesshowedsigni?cantlyhighervalues(p 0.05)ofL*
andb*valuesduringstoragethanthosewrappedwithC-?lmandCGT-?lm,respectively.Asigni?cantincreaseinL*andb*valuesofcontrolsamplesindicateddiscoloration.Thecolorofcontrolsamplesbecamegrayish(anincreaseinlightnessandadecreaseinredness)withanincreaseinstorageperiod.Changesfoundincolorvaluesofcontrolsampleswereprobablyduetolipidoxidationandmicrobialspoilage.Anaccumulationofhydrogenperoxideproducedbylacticacidbacteriaduringstorage(Cayré,Garro,&Vignolo,2005)maypossiblybeoneofthemainfactorsrespon-siblefordiscolorationofcontrolsamples.Theproducedperoxidecanreactwithnitricoxidehemochromogenornitricoxidemyoglobinandgiveoxidizedporphyrin,resultingingreeningofthemeatproducts(Jjaberg,Haugum,&Murmi,1970).
SampleswrappedwithC-?lmshowedlowerchangesincolorvaluesprobablyduetotheantioxidantandantimicrobialpropertiesofthechitosan?lm.Chitosanhasbeenreportedtoinhibitthegrowthofvariouspathogenicbacteria,yeastsandmolds(Chenetal.,1996),aswellaslacticacidbacteria(Comaetal.,2002),whicharepredominantincookedandcuredmeat(Samelisetal.,2000).TheresultsalsoshowedthatsampleswrappedwithCGT-?lmhadsigni?cantlylowerchanges(p 0.05)inL*andb*valuesthanthosewrappedwithC-?lm,probablyduetothe
内容需要下载文档才能查看antioxidant
Fig.3.ColorvaluesofcontrolporksausagesamplesandthosewrappedwithC-?lmandCGT-?lmduringstorageat4??C:(a)L*value;(b)a*value;(c)b*value.ValuesaregivenasmeanÆstandarddeviation.
106U.Siripatrawan,S.Noipha/FoodHydrocolloids27(2012)102e108
3.4.Texture
TextureofcontrolsamplesandthosewrappedwithC-?lmand
CGT-?lmduringstorageat4??CisshowninFig.4.Cuttingforceof
controlsampleswassigni?cantlylowerthanothersamples
throughoutthestorage.Thisisprobablybecausethegrowthof
spoilagemicroorganismsinthesausagesamples.Nosigni?cant
(p>0.05)differencebetweensampleswrappedwithC-?lmand
CGT-?lmwasobservedthroughoutthestorageperiod.Samples
wrappedwithC-?lmandCGT-?lmshowedlower(p 0.05)
changesincuttingforcethancontrolsamplesduetoantimicrobial
propertiesofthe?lmstoinhibitthegrowthofgram-positiveand
gram-negativebacteria,yeasts,andmolds(Shahidietal.,1999).
Fig.4.Texture(cuttingforce)ofcontrolporksausagesamplesandthosewrappedwith
C-?lmandCGT-?lm.ValuesaregivenasmeanÆstandard
内容需要下载文档才能查看deviation.3.5.Sensoryevaluation
Meansofsensoryattributescoresincludingodor,discoloration,
slimeformationandoverallacceptanceofcontrolporksausage
samplesandthosewrappedwithC-?lmandCGT-?lmduring
storageat4Æ1??CareshownFig.5.Thesensoryevaluation
resultsappearedtobecorrelatedtocolorindex,texture,TBAvalues,
andmicrobiologicalanalyses.
Thesensoryevaluationresultsshowedthatodorscoresdecreased
withincreasingstorageperiod(Fig.5a).Off-odoroccurredin
内容需要下载文档才能查看controlandantimicrobialeffectsofpolyphenoliccompoundsfromgreentea,includingEC,EGC,ECG,EGCG,C,GCG,CG,andGC(Chanetal.,2007;Farhooshetal.,2007;Yilmaz,2006).Theresultssuggestedthatincorporationofgreenteaintochitosan?lmcouldenhancetheantioxidativeandantimicrobialpropertiesofthe?lmandthusmaintainedthequalitiesofthesausagesamples.
Fig.5.SensoryevaluationofcontrolporksausagesamplesandthosewrappedwithC-?lmandCGT-?lmduringstorageat4??C:(a)odorscores;(b)discolorationscores;(c)slimeformationscores;(d)overallacceptancescores.
下载文档
热门试卷
- 2016年四川省内江市中考化学试卷
- 广西钦州市高新区2017届高三11月月考政治试卷
- 浙江省湖州市2016-2017学年高一上学期期中考试政治试卷
- 浙江省湖州市2016-2017学年高二上学期期中考试政治试卷
- 辽宁省铁岭市协作体2017届高三上学期第三次联考政治试卷
- 广西钦州市钦州港区2016-2017学年高二11月月考政治试卷
- 广西钦州市钦州港区2017届高三11月月考政治试卷
- 广西钦州市钦州港区2016-2017学年高一11月月考政治试卷
- 广西钦州市高新区2016-2017学年高二11月月考政治试卷
- 广西钦州市高新区2016-2017学年高一11月月考政治试卷
- 山东省滨州市三校2017届第一学期阶段测试初三英语试题
- 四川省成都七中2017届高三一诊模拟考试文科综合试卷
- 2017届普通高等学校招生全国统一考试模拟试题(附答案)
- 重庆市永川中学高2017级上期12月月考语文试题
- 江西宜春三中2017届高三第一学期第二次月考文科综合试题
- 内蒙古赤峰二中2017届高三上学期第三次月考英语试题
- 2017年六年级(上)数学期末考试卷
- 2017人教版小学英语三年级上期末笔试题
- 江苏省常州西藏民族中学2016-2017学年九年级思想品德第一学期第二次阶段测试试卷
- 重庆市九龙坡区七校2016-2017学年上期八年级素质测查(二)语文学科试题卷
- 江苏省无锡市钱桥中学2016年12月八年级语文阶段性测试卷
- 江苏省无锡市钱桥中学2016-2017学年七年级英语12月阶段检测试卷
- 山东省邹城市第八中学2016-2017学年八年级12月物理第4章试题(无答案)
- 【人教版】河北省2015-2016学年度九年级上期末语文试题卷(附答案)
- 四川省简阳市阳安中学2016年12月高二月考英语试卷
- 四川省成都龙泉中学高三上学期2016年12月月考试题文科综合能力测试
- 安徽省滁州中学2016—2017学年度第一学期12月月考高三英语试卷
- 山东省武城县第二中学2016.12高一年级上学期第二次月考历史试题(必修一第四、五单元)
- 福建省四地六校联考2016-2017学年上学期第三次月考高三化学试卷
- 甘肃省武威第二十三中学2016—2017学年度八年级第一学期12月月考生物试卷
网友关注
- 行政管理8102415
- 认真贯彻实施宪法和全面建设小康社会-国家法、宪法论文
- 【最新word论文】论宪法的适用【国家法专业论文】
- 东莞市工商行政管理局办公大楼综合布线项目doc
- 工程招标文件范本
- 哈密发展规划
- 竣工资料目录23419766
- 宣传宪法精神维护宪法权威-国家法、宪法论文
- 资料员必知15616165
- 党的路线方针政策07636
- 如何理解工业反哺农业、城市支持农村的方针
- 2014资料员e卷
- 金融法论文1(可编辑)
- 招标文件格式
- 经济法票据法知识要点
- 2010司法考试国际经济法新大纲变化新旧对比
- 全国主体功能区规划
- 人权的定义意义-国家法、宪法论文
- [整理版]泉币政策是国家为完成特定的微观经济目标而采用操纵和疗养泉币供应量的方针政策的总称
- 供用电技术
- 法律基础知识试题及答案
- 中国国家机构 发展和完善-国家法、宪法论文_95050
- 金融法排版(可编辑)
- 宁波市鄞州区十二五规划纲要
- 关于西方两大法系行政法的差异及其成因与发展趋势
- 2010版招标文件
- 国家十二五规划全文_8
- 井巷工程竣工资料
- 国家法、宪法论文-公民基本权利的规定方式、限制方式及体系安排——以宪法文本为限比较研究
- 发展党员新十六字方针提醒我们注意什么
网友关注视频
- 化学九年级下册全册同步 人教版 第18集 常见的酸和碱(二)
- 【获奖】科粤版初三九年级化学下册第七章7.3浓稀的表示
- 三年级英语单词记忆下册(沪教版)第一二单元复习
- 七年级下册外研版英语M8U2reading
- 19 爱护鸟类_第一课时(二等奖)(桂美版二年级下册)_T3763925
- 【部编】人教版语文七年级下册《泊秦淮》优质课教学视频+PPT课件+教案,湖北省
- 【部编】人教版语文七年级下册《过松源晨炊漆公店(其五)》优质课教学视频+PPT课件+教案,辽宁省
- 外研版英语三起5年级下册(14版)Module3 Unit1
- 冀教版小学英语五年级下册lesson2教学视频(2)
- 3月2日小学二年级数学下册(数一数)
- 沪教版牛津小学英语(深圳用) 四年级下册 Unit 8
- 【部编】人教版语文七年级下册《老山界》优质课教学视频+PPT课件+教案,安徽省
- 沪教版八年级下次数学练习册21.4(2)无理方程P19
- 外研版英语七年级下册module1unit3名词性物主代词讲解
- 北师大版数学四年级下册3.4包装
- 外研版英语三起6年级下册(14版)Module3 Unit2
- 第五单元 民族艺术的瑰宝_15. 多姿多彩的民族服饰_第二课时(市一等奖)(岭南版六年级上册)_T129830
- 北师大版数学 四年级下册 第三单元 第二节 小数点搬家
- 《空中课堂》二年级下册 数学第一单元第1课时
- 【部编】人教版语文七年级下册《逢入京使》优质课教学视频+PPT课件+教案,安徽省
- 沪教版牛津小学英语(深圳用)五年级下册 Unit 1
- 沪教版八年级下册数学练习册21.3(3)分式方程P17
- 冀教版小学数学二年级下册第二单元《有余数除法的简单应用》
- 冀教版小学数学二年级下册第二周第2课时《我们的测量》宝丰街小学庞志荣
- 七年级英语下册 上海牛津版 Unit3
- 第五单元 民族艺术的瑰宝_16. 形形色色的民族乐器_第一课时(岭南版六年级上册)_T3751175
- 人教版历史八年级下册第一课《中华人民共和国成立》
- 第12章 圆锥曲线_12.7 抛物线的标准方程_第一课时(特等奖)(沪教版高二下册)_T274713
- 化学九年级下册全册同步 人教版 第22集 酸和碱的中和反应(一)
- 8.练习八_第一课时(特等奖)(苏教版三年级上册)_T142692
精品推荐
- 2016-2017学年高一语文人教版必修一+模块学业水平检测试题(含答案)
- 广西钦州市高新区2017届高三11月月考政治试卷
- 浙江省湖州市2016-2017学年高一上学期期中考试政治试卷
- 浙江省湖州市2016-2017学年高二上学期期中考试政治试卷
- 辽宁省铁岭市协作体2017届高三上学期第三次联考政治试卷
- 广西钦州市钦州港区2016-2017学年高二11月月考政治试卷
- 广西钦州市钦州港区2017届高三11月月考政治试卷
- 广西钦州市钦州港区2016-2017学年高一11月月考政治试卷
- 广西钦州市高新区2016-2017学年高二11月月考政治试卷
- 广西钦州市高新区2016-2017学年高一11月月考政治试卷
分类导航
- 互联网
- 电脑基础知识
- 计算机软件及应用
- 计算机硬件及网络
- 计算机应用/办公自动化
- .NET
- 数据结构与算法
- Java
- SEO
- C/C++资料
- linux/Unix相关
- 手机开发
- UML理论/建模
- 并行计算/云计算
- 嵌入式开发
- windows相关
- 软件工程
- 管理信息系统
- 开发文档
- 图形图像
- 网络与通信
- 网络信息安全
- 电子支付
- Labview
- matlab
- 网络资源
- Python
- Delphi/Perl
- 评测
- Flash/Flex
- CSS/Script
- 计算机原理
- PHP资料
- 数据挖掘与模式识别
- Web服务
- 数据库
- Visual Basic
- 电子商务
- 服务器
- 搜索引擎优化
- 存储
- 架构
- 行业软件
- 人工智能
- 计算机辅助设计
- 多媒体
- 软件测试
- 计算机硬件与维护
- 网站策划/UE
- 网页设计/UI
- 网吧管理