An influence of cooking on fatty acid食品科学英文课件

1、Aninfluenceofcookingonfattyacidcompositioninthreevarietiesofcommonbeansandinlentil,Introduction,legumesarerichinimportantvitaminsandminerals,legumesarelowinfat(13%)legumesgoodsourcesofsolubleandinsolubledietaryfibre.,Introduction,Increasedn-3PUFAintakefrommarinesourceshasbeenshowntoreducetheriskofco

2、ronaryheartdisease,improveinflammatoryconditions,suchasarthritis,reduceplasmatriacylglycerollevelsandlowerbloodpressure.Thescientificliteraturehasshowntheabilityoflegumestodecreasetheglycemicindexandcholesterolomy,whichisduenotonlytotheprotectiveroleofdietaryfibre,butperhapsalsotothefavourableconten

3、toffattyacids.,Introduction,BeansareaverypopularfoodinSloveniaLentilsarewidelyconsumedinFranceTheaimofthisworkwastodeterminethefattyacidcompositionofthreevarietiesofSloveniancommonbeanandFrenchlentil,andtodeterminethechangesoccurringaftercookingandstorage.,Abstract,Thefattyacidcompositionofthreerawa

4、ndcookedfreeze-driedcommonbeanvarietiesandthelentil,wasdeterminedandtheinfluenceofstorageontheircompositionwasstudied.Analysesoffattyacidcompositionwereconductedbyinsitutransesterificationandcapillarycolumngas-liquidchromatography.,Abstract,Inrawmilledbeansaveragevaluesofabout16%saturatedfattyacids(

5、SAT),6%monosaturatedfattyacids(MUFA)and78%polyunsaturatedfattyacids(PUFA)werefound.Somewhatdifferentvaluesof15%ofSAT,25%MUFAand60%PUFAwerefoundinlentil.Incookedbeansthecontentofallfattyacidswasslightlydecreased.Incookedlentilthedecreasewasalmost50%,buttheratiosofSAT,MUFAandPUFAinbothcaseswerepractic

6、allythesame.,Abstract,Aftertwoyearsofstorageat4Cthefattyacidcontentinrawmilledbeanswasunchanged,butalteredincookedones.Theamountsoflinoleic(18:2,n-6)and-linolenic(18:3,n-3)aciddecreased,butmyristic(14:0),margaric(17:0)andarachidic(20:0)acidsincreased.Itwasfoundthatfreeze-driedcookedbeans,preparedfro

7、mrawseedbeans,kept2.5yearsat10C,havepracticallythesamefattyacidcompositionasfreezedriedcookedbeans0.5yearafterharvesting.,Keywords,CommonbeanLentilFattyacidcontentStorageAgeing,Materialandmethod,SampleThepreparingofBeansandLentilThemethodwasusedtodeterminetotalfats,Sample,Thethreemostwidelyuseddefin

8、edvarietiesofSloveniancommonbean:Cesnjevec,Semenarna22andCipro.TheCesnjevecandSemenarna22beansareSlovenianvarieties,whileCiproisaninternationalseedvariety;AdefinedsampleofthegreenmicrospermalentilLensesculentapuyensisvar.Anicia(LentilleVerteduPuy)wassentfromtheprovinceofHaute-Loire(France),whichisth

9、eoriginofthisvarietyoflentil.,Beansandlentilwerepreparedasfollows.,Procedure1Theselegumes,storedat10C,werepreparedsixmonthsafterharvesting.Samplesofbeansweresoakedfor18hintwovolumesofwater,andthenboiledinthatsameunsaltedwater.Theamountofwaterforsoakingandthetimeneededforcookingweredeterminedforeachs

10、ampleseparately.Thelentildidnotneedsoakingandwascookedbyboiling,accordingtotheinstructionsoftheproducer:20mininthreevolumesofunsaltedwater.Duringcookingofthedrylegumesthecookingpotwascovered.Aftercooking,legumeswereseparatedfromthecookingwaterandfreeze-dried.Rawandfreeze-driedcookedsamplesweremilled

11、withacyclonemillandanalysedimmediatelyforfattyacidcomposition.,Beansandlentilwerepreparedasfollows.,Procedure2Analiquotofmilledrawandmilledfreeze-driedcookedCesnjevecbeansamples,preparedasinProcedure1,wasstoredat4C,thenanalysedafteroneyearandtwoyearsofstorage.Procedure3TheseedofCesnjevecbean,afterha

12、rvesting,wasstoredat10Cfor2.5yearsandthenpreparedinthesamewayasdescribedinProcedure1.,Gaschromatography,HewlettPackard5890seriesIgaschromatographFlameionisationdetector(FID),HP-20MCapillarycolumn(Carbowax20M,50m0.32mm0.3m)Integrator,HewlettPackard3392A,Gaschromatography,Theoventemperature:from140C(0

13、min)at7Cmin1,to215C(81.29min)Theinjectortemperature:250CThedetectortemperature:290C.Splitinjectionwasmadeata30to1ratio;volume1l.ThecarriergaswasAr,2mlmin-1,andthemake-upgasN2,33mlmin-1.ThegasesinthedetectorwereH2,33mlmin-1andsyntheticair(21%O2),330mlmin-1.,FAMEswereidentifiedbycomparisonofretentiont

14、imeswithstandardsTheconcentrationsofFAMEswerecalculatedbyuseofappropriateresponsefactors(Rf)basedonastandardmixtureTheconversionfactorsofFAMEtoFAwereusedforcalculationoftheweightpercentsoffattyacidofthetotalFAs,0.80,Aninternalstandardofnonadecanoicacidusedforrawandfreeze-driedcookedCesnjeveccommonbe

15、an,prepared2.5yearsafterharvesting,Solidnonadecanoicacid,Hexaneandmethanol,Hachtube,Diluted,Evaporated,Sample,GCanalysis,Resultsanddiscussion,Table1.ComparisonofcertifiedvaluesforCRM164anhydrousmilkfatwithourvalues(gFAi/(100g)FA),Table2.Fattyacidcomposition(mg100g1dryweightsample)andtotalfatcontenti

16、nrawandcookedcommonCesnjevecbean(Procedure3),Table3.Averagefattyacidcompositionandtotalfatcontentofsamplesofrawbeansandlentil(mgFA/(100g)dryweightsample),Table4.Averagefattyacidcompositionandtotalfatcontentofcookedsamplesofbeansandlentil,Intermsofspecificfattyacids,weweremostinterestedinthelinoleica

17、cidand-linolenicacidcontents,becausebothareessentialforhumansandanimals.Theconcentrationandproportionoflinoleic(n-6)to-linolenicacid(n-3)areverydifferentinbeansandlentil:inrawCesnjevecbeanandthetwoothervarietiesofbeantheratiois1:1.91,butinlentilitis1:0.33andcookingdoesnotmodifythischaracteristic.Now

18、theamountoffatsinhumannutritionincreased,especiallyonaccountofsaturatedandn-6fattyacids.Ontheotherhand,theproportionofn-3fattyacidsdecreasedandtheratiobecamelargerthan10:1.-Linolenicacidisalsoimportantasaprecursorforeicosapentaenicacid(EPA)anddocosahexaenoicacid(DHA),whichwerenotfoundinthelegumeseed

19、s,butcanbesynthesizedinthebody.Fromthispointofview,beanhasmorefavourableproportionsofn-6andn-3fattyacids.,Table5.Stabilityoffattyacidsinraw(R)andcooked(C)Cesnjevecbean,Thefattyacidprofileofthreevarietiesofrawbeanseedswasverysimilar,butdifferentfromrawlentilseeds.Thefattyacidcontentofrawbeansandlentilmostlydifferedinthehigheramountofpalmitic(16:0),oleic(18:1,n-9),linoleic(18:2,n-6)andarachidic(20:0)acidsandthesmalleramountof-linolenic(18:3,n-3)acidinrawlentil.Incookedsamplesthedifferencesweresmaller,becausethecontentofallfattyacidswassimilar,butstillthecontentofPUFAwashi