食品营养与安全18章要点 2.docx

食品营养与安全18章要点 2.docx

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食品营养与安全18章要点2

Chapter1FoodChoicesAndHumanHealth

Food:

medically,anysubstancethatthebodycantakeinandassimilatethatwillenableittostayaliveandtogrow,thecarrierofnourishment;

socially,amorelimitednumberofsuchsubstancesdefinedasacceptablebyeachculture.

Diet:

thefood（includingbeverages）apersonusuallyeatsanddrinks.

Nutrition:

thestudyofthenutrientsinfoodsandinthebody;sometimesalsothestudyofhumanbehaviorsrelatedoffood.

Nutrients:

componentsoffoodthatareindispensabletothebody’sfunctioning.Theyprovideenergy,serveasbuildingmaterial,helpmaintainorrepairbodyparts,andsupportgrowth.

Nutritionprofoundlyaffectshealth:

malnutrition营养失衡andchronicdiseases.

Malnutrition:

anyconditioncausedbyexcessordeficientfoodenergyornutrientintakeorbyanimbalanceofnutrients.

Thenutrientsincludewater,carbohydrate,fat,protein,vitaminsandminerals.Foodsuppliesenergyandnutrients.Themostvitalnutrientiswater.Theenergy-yieldingnutrientsarecarbohydrates,fats（lipids）,andprotein.Thehelpernutrientsarevitaminsandminerals.

Q:

Whatexactlyisanutritiousdiet?

Adequacy:

thefoodprovideenoughofeachessentialnutrient,fiber,andenergy.

Caloriecontrol:

thefoodsprovidetheamountofenergyyouneedtomaintainappropriateweigh——notmore,notless.

Moderation:

thefooddonotprovideexcessfat,salt,sugar,orotherunwantedconstituents.

Variety:

thefoodschosendifferfromonedaytothenext.

Balance:

thechoicesdonotoveremphasizeonenutrientorfoodtypeattheexpenseofanother.

Chapter2NutritionTools——StandardsandGuidelines

RecommendedDietaryAllowances（RDA）wasusedinU.S.andRecommendedNutrientIntakes（RNI）wasusedinCanada.

Today,bothofthesestandardsarebeingreplacedbytheDietaryReferenceIntakes（DRI）

膳食参考摄入量包括以下四个方面：

EAR:

EstimatedAverageRequirement膳食推荐允许量

RDA:

RecommendedDietaryAllowances预计平均需要量

AI:

AdequateIntakes适宜摄入量

UL:

TolerableUpperIntakeLevels可耐受最高摄入量

EAR,RDA,AI,UL；Howdotheydiffer?

RecommendedDietaryAllowances（RDA）：

Nutrientintakegoalsforindividuals;theaveragedailynutrientintakelevelthatmeettheneedsofnearlyall（97to98percent）healthypeopleinaparticularlifestageandgendergroup.

EstimatedAverageRequirement（EAR）：

Theaveragedailynutrientintakeestimatedtomeettherequirementofhalfofthehealthyindividualsinaparticularlifestageandgendergroup;

AdequateIntakes（AI）：

Nutrientintakegoalsforindividuals;therecommendedaveragedailynutrientintakelevelbasedonintakesofhealthypeople（observedorexperimentallyderived）inaparticularlifestageandgendergroupandassumedtobeadequate.

TolerableUpperIntakeLevels（UL）：

Thehighestaveragedailynutrientintakelevelthatislikelytoposenoriskoftoxicitytoalmostallhealthyindividualsofaparticularlifestageandgendergroup.

Q1:

Whycan’tnutrientadvicebekeptsimple?

Settingintakerecommendationforindividuals

Preventingchronicdiseases

Facilitatingnutritionresearchandpolicy（EAR）

Establishingsafetyguidelines（UL）

Makinggoodtoolsbetter

Q2：

HowthecommitteeestablishesDRIvalues?

（1）Findouthowmuchofthatnutrientvarioushealthyindividualsneed:

reviewstudiesofdeficiencystates,nutrientstoresandtheirdepletion,andthefactorinfluencingthem.

（2）Differentindividualshavedifferentrequirement:

average——EAR

（3）Todecisionwefinallymakeistosetthevaluehighenoughsothatthebulkofthepopulationwillbecoveredbutnotsohighastobeexcessive——RDA

（4）Thevaluesetforenergyintakeisdifferentfromnutrient.

FoodLabels

Listofingredients

Listedindescendingorderbyweight

Chapter3TheRemarkableBody

1.Thehumanbodyismadeoftrillionsofcells

Livercells:

reproducequicklyanddosowheneverrepairstotheorganareneeded

Braincells:

donotreproduceatall;ifdamagedbyinjuryordisease,lostforever

2.TheBodyFluidsandtheCardiovascularSystem

Thebody’smainfluidsarethebloodandlymph

Blood:

arteries,veins静脉andcapillaries毛细血管

Lymph:

travelsinseparatevesselsofitsown

Bodyfluidsupplythetissuescontinuouslywithenergy,oxygen,andnutrientsincludingwater.

Bloodandlymphdelivernutrientsandoxygentoallthebody’scellsandcarrywastematerialsawayfromthem.

3.Thehormonalandnervoussystemsrespondtotheneedforfood,governtheactofeating,regulatedigestion,andcallforthestressresponse.

4.TheImmuneSystem

Maintaindefensesagainstinfection:

Skin:

physicalbarrier

Whitebloodcells

Phagocytes（吞噬细胞）

Lymphocytes（淋巴细胞）:

--B-cells:

produceantibody

--T-cells:

attackantigen

Theimmunesystemenablesthebodytoresistdisease.

5.TheDigestiveSystem

Beginsinthemouth:

chewing

salivamoistensfoodforeasierswallowing

Stomachandintestinesliquefyfoodsbymashingandsqueezing

Smallintestine–siteofmostnutrientabsorption-contractstomovecontentstolargeintestine（colon）

Colon’smainroles:

Reabsorbwater

Absorbminerals

Rectum（直肠）—storesfecesuntilexcretion

fiber,undigestedmaterial,sloughedintestinalcells,bacteria

Chapter4Carbohydrates：

Sugar,Starch,Glycogen,andFiber

Glucose葡萄糖fructose果糖Galactose半乳糖

Lactose乳糖Maltose麦芽糖Sucrose蔗糖

益生菌（probiotics）：

对身体有好处的“好菌”，是一种可改善宿主肠內菌相平衡，有益宿主健康的活微生物体——双歧杆菌、乳酸菌。

益生源（prebiotics）：

是指可以刺激腸道里的好菌生长的“食物”，这类物质能够被有益菌利用而产生有机酸，刺激肠蠕动，并且能促进有益菌生长，抑制坏菌数量，使肠道更健康——寡糖

Starchisaplant’sstorageformofglucose.Plantstoreenergyasstarchforuseduringgrowthandreproduction.

Richsourcesofstarch:

-Grains:

wheat,rice,corn,oats…

-Legumes:

peas,bean,lentils…

-Tubers:

potatoes,yams,cassava…

Nutritiveforhumans:

itisanimportantcarbohydratessourceofourdiets.

Glycogen

Storageformofglucoseinanimalsandhumanbeings.

Undetectableinmeatsbecauseglycogenbreaksdownrapidlywhentheanimalisslaughtered.

Sinceplantfoodsdonotcontainglycogen,itisn’tacarbohydratesourceinourdiets.Butglycogenplayanimportantroleinourbodyasareadilymobilizablestoreofglucose.

Lactoseintolerance

Aspeopleage,upwardof75percentoftheworld’speoplelosetheabilitytoproducetheenzymelactasewhichdigestslactose

Milkallergyisduetotheimmunesystem’sreactiontomilkprotein.

Harmtothebody

Chronicallyelevatedbloodglucosealtersmetabolismineverycellinthebody

-Blindness

-Kidneydisease

-Heartdisease

-Nervedamage

-Increasedinfections

Q1:

Fiberbenefitsthebodyinalltheseways

-Improvethebody’shandingofglucoseandthehormoneinsulin,perhapsbyslowingthedigestionorcarbohydrate.

-Possiblyreducetheriskofcoloncancer.

-Reduceenergyconsumption.

-Reducetheriskofheartandarterydisease.

-Helpfeelingsoffullnessbecausetheyabsorbwaterandswell.

-Helppreventconstipation,hemorrhoidsandotherintestinalproblemsbykeepingthecontentsoftheintestinemoistandeasytoeliminate.

-Helppreventbacterialinfectionoftheappendix.

-Stimulatethemusclesofthedigestivetractsothattheyretaintheirhealthandtone.

Whataretheconsequenceofeatingtoomuch？

Toomuchfiberandtoolittleliquidscanoverwhelmthedigestivesystem.

Toomuchpurifiedfibermaydisplacenutrientsfromthedietorcausethemtobelostbybindingthenutrientsandspeedinguptransit.

Thedailyvalueforfiberis25-30gperday.

Q2：

Howcanfiberhelpmaintainahealthyweight?

-Wholefoodsrichincarbohydratetendtobelowinfactsandaddedsugarsandthereforepromoteweightlossbydeliveringlessenergyperbite.

-Fiberprovidesafeelingsoffullness.

-Fiberdelayshungerbecausefibersswellastheyabsorbwater.

45-65%oftotalcaloriesisrecommendedtobeprovidedbycarbohydrates

Monosaccharide单糖,disaccharide二糖andpolysaccharide多糖

Polysaccharide:

longchainsofmonosaccaride

TheBody’sUseofGlucose:

SplittingGlucoseforEnergy

StoringGlucoseasGlycogen

MaintainingGlucoseintheBlood

Q3：

PreventingType2diabetes

-Maintainhealthybodyweight

-Chooseadiethighinvegetables,fruits,poultry,fish,andwholegrains

-Exerciseregularly

-Restrictalcohol

-Abstainfromsmoking

Q4：

Managementofdiabetes

-Thetighterthecontroloverbloodglucose,themildertheeffectsofdiabetescanbe

Lifestylechanges

-Eatahealthydietthatdeliversthesameamountofcarbohydrateeachday,spacedevenlythroughouttheday

-Nottoomuchprotein

-Adequateinfiber

-Lowinfat

Chapter5Thelipids:

Fats,Oils,Phospholipids,andSterols

Keeptotalfatintakebetween20to35%ofcaloriesfrommostlypolyunsaturatedandmonounsaturatedfatsourcessuchasfish,nuts,andvegetable.

Hydrophoblic疏水的Hydrophilic亲水的

1、Whatisthemostcommonformoflipidfoundinfood?

Triglycerides,Phospholipids,Sterols.

2、Usefulnessoflipid

Inthebody

Fatisthebody’schiefstorageformofenergyfromfoodeatenintheexcessofneed.

Fatsprovidemostoftheenergyneededtoperformmuchofthebody’swork.

Padsoffatsurroundinginvitalorgansserveasshockabsorbers.

Thefatblanketundertheskinalsoinsulatesthatbodyfromextremesoftemperature.

Someessentialnutrientsaresolubleinfatandthereforearefoundmainlyinfoodsthatcontainfat.

Infood

Theenergydensityoffatsfoodsmakesfoodsrichinfatvaluableinmanysituations.

Fatcarrieswithitmanydissolvedcompoundsthatgivegoodsenticingaromasandflavors.

Fatlendstendernesstofood.

Fatsprovidessatiety,thelastingsatisfactionoffeelingafterameal.

3、ListMajorLipoproteins.DescribethedifferencebetweenLDLandHDLintermsofcholesterolandproteincomposition?

Chylomicron乳糜微粒

Very-low-densitylipoproteins（VLDL）,whichcarrytriglyce