食品化學雙語試卷及答案

一、單項選擇題1.Whichofthefollowingisareducingsugar?A.SucroseB.GlucoseC.StarchD.CelluloseAnswer:B2.Themaincomponentofthecellmembraneinfoodcellsis___.A.ProteinB.LipidC.CarbohydrateD.NucleicacidAnswer:B3.Whichvitaminiseasilyoxidizedinfood?A.VitaminAB.VitaminB1C.VitaminCD.VitaminDAnswer:C4.TheMaillardreactionmainlyoccursbetween___.A.ProteinsandlipidsB.CarbohydratesandproteinsC.CarbohydratesandlipidsD.LipidsandvitaminsAnswer:B5.Whichofthefollowingenzymescanbreakdownstarch?A.ProteaseB.LipaseC.AmylaseD.CellulaseAnswer:C6.Thecolorofmeatismainlydeterminedby___.A.MyoglobinB.HemoglobinC.CytochromeD.ChlorophyllAnswer:A7.Whichofthefollowingisanessentialfattyacid?A.PalmiticacidB.StearicacidC.LinoleicacidD.OleicacidAnswer:C8.Theflavorofgarlicismainlydueto___.A.AliphatichydrocarbonsB.AromatichydrocarbonsC.Sulfur-containingcompoundsD.Nitrogen-containingcompoundsAnswer:C9.Whenfoodisfrozen,themainchangeinwateris___.A.EvaporationB.SublimationC.CrystallizationD.DecompositionAnswer:C10.Whichelementisanimportantcomponentofchlorophyll?A.IronB.MagnesiumC.CalciumD.PotassiumAnswer:B二、多項選擇題1.Whichofthefollowingarepolysaccharides?A.StarchB.CelluloseC.GlycogenD.SucroseAnswer:ABC2.Thefactorsthataffecttherateoflipidoxidationinclude___.A.TemperatureB.OxygenconcentrationC.PresenceofmetalionsD.LightAnswer:ABCD3.Whichvitaminsarefat-soluble?A.VitaminAB.VitaminB2C.VitaminDD.VitaminEAnswer:ACD4.Thefunctionsofproteinsinfoodinclude___.A.ProvidingnutritionB.GelationC.EmulsificationD.FoamingAnswer:ABCD5.Whichofthefollowingarenaturalfoodcolorants?A.CarotenoidsB.ChlorophyllC.AnthocyaninsD.TartrazineAnswer:ABC6.ThemethodstoinhibittheMaillardreactioninclude___.A.LoweringthetemperatureB.ReducingthewateractivityC.AddingantioxidantsD.AdjustingthepHAnswer:ABCD7.Enzymesinfoodcancause___.A.ColorchangesB.FlavorchangesC.TexturechangesD.NutrientlossesAnswer:ABCD8.Thepropertiesofwaterinfoodareimportantbecauseitaffects___.A.ThefreshnessoffoodB.ThestabilityoffoodC.ThetextureoffoodD.TheflavoroffoodAnswer:ABCD9.Thefunctionsoflipidsinfoodare___.A.ProvidingenergyB.Carryingfat-solublevitaminsC.ImprovingfoodflavorD.AffectingfoodtextureAnswer:ABCD10.Whichofthefollowingcanaffectthedenaturationofproteins?A.TemperatureB.pHC.PresenceofsaltsD.MechanicalagitationAnswer:ABCD三、判斷題1.Allcarbohydratesaresweet.(False)2.Lipidsareinsolubleinwaterbutsolubleinorganicsolvents.(True)3.VitaminCisawater-solublevitaminandisverystableduringfoodprocessing.(False)4.TheMaillardreactionalwayshasanegativeimpactonfoodquality.(False)5.Enzymescanonlycatalyzereactionsinlivingorganismsandnotinfoodsystems.(False)6.Thecoloroffruitsandvegetablesismainlyduetothepresenceofpigments,andthesepigmentsdonotchangeduringstorage.(False)7.Wateractivityisanimportantfactoraffectingthegrowthofmicroorganismsinfood.(True)8.Proteinscanbedenaturedbyhightemperature,buttheirnutritionalvaluewillnotchange.(False)9.Allnaturalfoodcolorantsarecompletelysafeandcanbeusedwithoutlimit.(False)10.Theflavoroffoodisonlydeterminedbyvolatilecompounds.(False)四、簡答題1.Explaintheconceptofwateractivityinfood.Wateractivity(aw)isameasureoftheavailabilityofwaterinfood.Itisdefinedastheratioofthevaporpressureofwaterinthefood(P)tothevaporpressureofpurewater(P0)atthesametemperature.Wateractivityrangesfrom0to1.Lowwateractivitymeansthatwaterisstronglyboundtofoodcomponents,anditaffectsthegrowthofmicroorganisms,chemicalreactions,andthestabilityoffood.Microorganismsgenerallyrequireacertainminimumwateractivitytogrow.2.Whatarethemaindifferencesbetweenreducingsugarsandnon-reducingsugars?Reducingsugarshaveafreealdehydeorketonegroupthatcanbeoxidized.TheycanreactwithsubstanceslikeBenedict'sreagentorFehling'sreagenttoproduceacolorchange.Examplesincludeglucoseandfructose.Non-reducingsugarsdonothaveafreealdehydeorketonegroupavailableforoxidationundernormalconditions.Sucroseisanon-reducingsugar.Thisdifferenceisimportantinfoodanalysisandinunderstandingthechemicalbehaviorofsugarsduringfoodprocessing.3.Describetheprocessoflipidoxidationinfood.Lipidoxidationinfoodisacomplexprocess.Itusuallystartswiththeinitiationstep,wherefreeradicalsareformed,oftenduetofactorslikelight,heat,orthepresenceofmetalions.Inthepropagationstep,thesefreeradicalsreactwithoxygentoformperoxy-freeradicals,whichthenreactwithotherlipidstoformmorefreeradicals.Finally,intheterminationstep,freeradicalscombinewitheachothertoformnon-radicalproducts.Lipidoxidationcanleadtooff-flavors,reducednutritionalvalue,andchangesinfoodtexture.4.Howdoesheattreatmentaffectthequalityofproteinsinfood?Heattreatmentcancauseproteindenaturation.Thesecondary,tertiary,andquaternarystructuresofproteinsaredisrupted.Thiscanleadtochangesinthetextureoffood,suchasthecoagulationofeggwhiteduringcooking.Heattreatmentcanalsoimprovethedigestibilityofsomeproteinsasthestructurebecomesmoreaccessibletodigestiveenzymes.However,excessiveheatcancausetheformationofundesirablecompoundsandlossofnutritionalvalue,especiallyifessentialaminoacidsaredamaged.五、討論題1.Discusstheimportanceoffoodchemistryinensuringfoodsafetyandquality.Foodchemistryiscrucialforfoodsafetyandquality.Understandingthechemicalreactionsinfoodhelpsincontrollingspoilage.Forexample,knowinghowlipidsoxidizeallowsustouseantioxidantstopreventrancidity.Intermsofsafety,knowledgeoffoodchemistryhelpsindetectingandpreventingtheformationofharmfulsubstancesliketoxinsproducedbyMaillardreactionundercertainconditions.Italsohelpsinformulatingproperpreservationmethods.Byunderstandingthepropertiesoffoodcomponents,wecanensurethatfoodretainsitsnutritionalvalue,flavor,andtextureduringstorageandprocessing,meetingconsumerexpectations.2.Analyzetheimpactoffoodprocessingonthenutritionalvalueoffoodfromtheperspectiveoffoodchemistry.Foodprocessingcanhavebothpositiveandnegativeimpactsonnutritionalvalue.Positiveimpactsincludeincreaseddigestibilityofsomenutrients.Forexample,cookinggrainsbreaksdownstarch,makingitmoreaccessiblefordigestion.Heattreatmentcanalsoinactivateanti-nutritionalfactors.However,negativeimpactsarealsocommon.Processingcanleadtonutrientlosses.Forinstance,water-solublevitaminslikevitaminCcanbelostduringblanchingorcookinginwater.Lipidoxidationduringfryingcanreducethecontentofessentialfattyacids.Understandingthesechemicalchangeshelpsinoptimizingprocessingmethodstominimizenutrientlosses.3.Howcanweusefoodchemistryknowledgetodevelopnewfoodproducts?Foodchemistryknowledgecanbeusedinmanyways.Wecanuseourunderstandingofthepropertiesoffoodcomponentstocreatenewtextures.Forexample,bycombiningdifferenthydrocolloids,wecandevelopuniquegel-likeorcreamytextures.Knowledgeofflavorchemistryallowsustocreatenewflavorcombinations.Understandingthechemicalreactionsduringprocessinghelpsindevelopingnewpreservationtechniquesforthenewproducts.Wecanalsodesignproductsw