专业技能英语实训报告.docx

专业技能英语实训报告.docx

《专业技能英语实训报告.docx》由会员分享，可在线阅读，更多相关《专业技能英语实训报告.docx（10页珍藏版）》请在冰豆网上搜索。

专业技能英语实训报告

专业技能英语实训报告

专业:

食品科学与工程

班级：

131

姓名：

成玲

学号：

2013035102

StudyonantioxidantactivityofpolysaccharidefromChineseRiceWineinvitro

Abstract：

TheantioxidantactivityofthepolysaccharidefromChineseRiceWinebyalcoholprecipitationwascontrastedinthepresentstudy.Thetotalantioxidantactivity，DPPHradical，hydroxylradicalandsuperoxideanionfreeradicalwereselectedastheantioxidantindicatorsinvitroandascorbicacid（VC）asthepositivecontrol.TheresultsshowedthatcrudepolysaccharideandrefinedpolysaccharidefromChineseRiceWinehadantioxidantactivity，andtheantioxidantactivitywasrelatedtoconcentration.Theantioxidantabilityofrefinedpolysaccharideintotalantioxidantactivity，removingtheDPPHradicalandhydroxylradicalwasbetterthanthatofcrudepolysaccharide.However，theantioxidantabilityofcrudepolysaccharideinremovingsuperoxideanionfreeradicalwasstrongerthanthatofrefinedpolysaccharide.

Keywords：

ChineseRiceWine；polysaccharide；alcoholprecipitation；antioxidant；

Chinesericewineistheoldesttraditionalbrewingwine,anditisoneoftheworld'sthreelargestancientwinefullbodied,YellowWinethemellow,softwine.Chinesericewinewithitswonderfulcoloranditsname,withitsuniquetaste,richnutritionanditshealthcarefunctionandknowntotheworld.ResearchshowsthatChineseWinehasantioxidantactivityandantioxidantactivityofsubstancescontainingtheantioxidantactivityandtheYellowWine,suchaspolyphenolsandpeptideetc.Alargenumberofstudieshaveindicatedthatpolysaccharidehasantioxidantactivity.Theyellowricewinecontainspolysaccharides,whetherornotithasantioxidantactivity,theresearchonthisaspecthasnotbeenreportedinanyreport.Therefore,Shaoxingyellowricewinewasusedasrawmaterial,andthepolysaccharidewasextractedfromtherawmaterials,andtheDPPHfreeradical,hydroxylfreeradicalandsuperoxidedismutasewereextractedbytheinvestigationofthecrudepolysaccharideandtherefinedyellowricewine.Anionanditstotalantioxidantcapacity,preliminarystudyoftheantioxidantactivityinvitro,whichprovidesscientificbasisforthefurtherresearchandutilizationofyellowricewine.

1Materialsandmethods

1.1MaterialsandExperimentalequipment

YellowWine（brewinginthewinterof2010,ZhejiangGuyueLongshan,ShaoxingwineLimitedbyShareLtd）,1,1-2-3phenyl4-dinitrophenylhydrazine（1,1-diphenyl-2-picrylhydrazyl,DPPH）AmericaSigma,bovineserumalbumin,glucose,ascorbicacid,CoomassiebrilliantblueG-250,adjacentbenzenethreephenolandconcentratedsulfuricacid,salicylicacid,threechloroaceticacid,potassiumferricyanide,chloroform,positivebutanolandotherreagents,722s（spectrophotometerShanghaiPrecisionScientificInstrumentCo.Ltd）,IKABeiRV10rotaryevaporator（GermanyIKAgroup）,freezedryer（AmericaLABCONCO）,highspeed（centrifugeMizueAnalysisInstrumentCoLtd）,UV-2450UVspectrometer（ShimadzuCorporation）.

1.2Experimentalmethods

1.2.1ExtractionandseparationofPolysaccharidefromChinesericewine

ThewineYellowWinedecompressionat55DEGC,concentratedtotheoriginalvolumeof1/3,adding95%ethanolconcentratedsolutioninethanolconcentrationreached30%,4Cstandingovernight,centrifugal（6000r/min,15min）,thesupernatantwascollected;thenadd95%ethanoltothesupernatantethanolconcentrationreached75%,stirring,4DEGCstandingovernight,centrifugal（6000r/min,15min）,collectingalcoholprecipitation;toadd30%ethanolalcoholintheresolution4Cstandingovernight,centrifugal（6000r/min,15min）,thesupernatantsupernatantwascollected;55degreesofreducedpressureconcentrationobtainedYellowWinecrudepolysaccharide（starchbyfreezedryingexperimentsshowthatYellowWinecrudepolysaccharidewasnonstarchpolysaccharide）.

Afterthecrudepolysaccharidewasaddedtowater,theSevagemethodwasusedtoremovetheimpurities,suchasinorganicions,aminoacids,oligosaccharides,andsoon.The72hwasusedtoremovetheimpuritiessuchasinorganicions,aminoacids,oligosaccharidesandsoon.

1.2.2DeterminationofpolysaccharideinChinesericewine

1.2.2.1Determinationoftotalsugar

Determinationoftotalsugarcontentinyellowricewinebyusingphenol-sulfuricacidmethods,referredtothegrapesugar.

1.2.2.2Determinationofreducingsugarcontent

DeterminationofreducingsugarcontentinyellowricewinebyusingDNSmethod,referredtothegrapesugar.

1.2.2.3Determinationofpolysaccharide

Polysaccharide=totalsugarreducingsugar.

1.2.3Determinationoftotalantioxidantcapacity

1mLofdifferentconcentrationsofpolysaccharidesolution,addingconcentrationofPBSsolution1mLand0.2mol/Lmassfractionof1%pH6.6potassiumferricyanide1mL,50DEGCwaterbath20min,fastcoolingafteradding10%threechloroaceticacid1mL,（4000r/min,5min）,centrifugalsupernatant2mL,addingdistilledwaterandqualityvolumefractionof0.1%ferricchloride0.4mL,mixing,static10min,theabsorbancewasdeterminedat700nm.Accordingtothesamemethod,theabsorbancevalueoftherefinedricewinewithdifferentconcentrationsandthepositivecontrolVCweredetermined,andtheaveragevalueofthe3timewasmeasured.

1.2.4DeterminationoffreeradicalscavengingabilityofDPPH

ReferenceCHIOtheCWandothermethodsfordeterminationoftheLIXL,etc.Thebasicstepsare:

differentconcentrationsofpolysaccharidesolution2mL,addingvolumeconcentrationofDPPH0.1mmol/Lsolution（preparedwithethanol）,aftermixinglightreactionof30minatroomtemperature（6000r/min,10min）,centrifugalsupernatantwasdeterminedbyAiin517nm;andwith4mLethanolanddistilledwater（two2mLrespectively）aszero.Theblankcontrolgroupwas2mLsamplesolutionwith2mLabsoluteethanol,theabsorbanceat517nmwasAj,theblankcontrolgroupwassettoremovethelightabsorptionvalueofthepolysaccharide.ThemodelcontrolgroupwasDPPH2mLsolutionplus2mLabsoluteethanol,itsabsorbanceatAcwas517nm.UsingthesamemethodtomeasuretheabsorbanceoftherefinedricewinewithdifferentconcentrationsandthepositivecontrolVC,theaveragevalueofthe3timeswasmeasured.AccordingtothefollowingformulatocalculatethesampletoDPPHfreeradicalscavengingrate:

ThesampletoDPPHfreeradicalscavengingrate（%）=[1-（Ai-Aj）/Ac]*100

1.2.5Determinationofhydroxylfreeradicalscavengingcapacity

TheFentonreactionsystemmodelwasusedtodeterminethehydroxylradicalscavengingactivitybyafixedtimereactionmethod.ThereactionsystemcontainedH2O29mmol/L,FeSO49mmol/L,8.8mmol/Lsalicylicacid（preparedwithanhydrousethanol）andcrudepolysaccharidesolutionwithdifferentconcentrationofyellowricewine.Thevolumeofthereactionsystemwas1mL.Withdistilledwaterasthereference,thefinaladditionofH2O2startupreaction,37Creaction30min,theabsorbanceofthereactionsystemwasmeasuredat510nmAx.Thepolysaccharidewasreplacedbywater,andtheabsorbanceofthemodelcontrolgroupwasA0.Takingintoaccounttheabsorbancevalueofthepolysaccharideitself,withequalvolume（9mmol/L）ofFeSO49mmol/L,lmLsalicylicacidethanol,differentconcentrationsofpolysaccharidesolutionanddistilledwaterasamixtureofthebackgroundabsorptionvalueofAx0.UsingthesamemethodtomeasuretheabsorbanceoftherefinedricewinewithdifferentconcentrationsandthepositivecontrolVC,theaveragevalueofthe3timeswasmeasured.Thefreeradicalscavengingrateofthesampleiscalculatedasfollows:

Sampletohydroxylradicalscavengingrate（%）=[1-（Ax-Axo）/Ao]*100

1.2.6Determinationofsuperoxideanioncapacity

Bythedevelopmentofthreephenolautoxidationmethod,thebasicstepsare:

50mmol/LpH8.2Tris-HCl4.5mL4.2mLbuffersolutionanddistilledwatermixing,25DEGCwaterbathtemperature20min,add25degreespreheated3mmol/Ladjacentbenzenethreephenol1mLimmediatelyafterremoving（preparedwith10mmol/LHClzero10mmol/LtubeforHClinsteadoftheadjacentbenzenethreephenolsolutionquickly,HCl）shakeandpourintothecuvette（lightsize1cm）,at325nmevery30secondstodeterminealightabsorptionvalue（A）,thelinearrangeincreasedtoAperminutevalueisadjacentbenzenethreephenolself-oxidationrate（A1）.Tris-HClpH8.2buffersolution4.5mLanddifferentconcentrationsofcrudepolysaccharidesolution4.2mLmix,theotherstepsasabove,thelinearrangeofAperminuteincreaseinvaluethatisaddedtothesampleafterthethreephenoloxidationrate（A2）.InthesamemethodtomeasuretheabsorbanceofrefinedricewinewithdifferentconcentrationsandthepositivecontrolVC,3timesinparallel.Thescavengingrateofsuperoxideanionradicalwascalculatedaccordingtotheformula:

Scavengingrateofsuperoxideanioninsamples（%）=[1-（A1-A2）/A1]*100

1.2.7Statisticalanalysis

SPSS17softwarewasusedtoanalyzethedataofsinglefactoranalysisofvariance（ANOVA）,andtheresultswereexpressedasmeanplusorminusstandarddeviation,andthesignificantlevelwasp<0.05.

2Resultsandanalysis

2.1DeterminationofpolysaccharideinChinesericewine

Accordingtothe1.2.2methodtomeasurethecontentoftotalsugarandreducingsugarcontentinwineYellowWineandpolysaccharidecontentresultsintable1.

Table1Cotentoftotalsugar，reducingsugarandpolysaccharideinChineseRiceWine（x±SD）

Name

totalsugar

reducingsugar

polysaccharide

Content（g/L）

46.889±1.345

30.195±0.287

16.694±1.096

2.2TotalantioxidantcapacityofChinesericewine

Inthereactionsystem,thegreatertheabsorbancemeasuredatthewavelengthof700nm,thestron