1 EGGS! EGGS!
Mar 31, 2015
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What we’re doing today What we’re doing today folks!folks!
HistoryHistory EtiologyEtiology HealthHealth Dissecting the eggDissecting the egg Good Egg, Bad Good Egg, Bad
EggEgg Cooking Cooking
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Background HistoryBackground History 300 mya- eggs laying in the ocean300 mya- eggs laying in the ocean
100 mya- mineralized egg shell100 mya- mineralized egg shell
8 mya- Gallus genus formed8 mya- Gallus genus formed
3-4 mya- Gallus gallus chicken species 3-4 mya- Gallus gallus chicken species formedformed
7500 BCE domestication SE Asia7500 BCE domestication SE Asia
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Background HistoryBackground History
Egg + Sperm = Fertilization -> Egg + Sperm = Fertilization ->
Egg + no sperm = Egg + no sperm =
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Health - AllergiesHealth - Allergies
Cause from ovalbumin Cause from ovalbumin NOTNOT the the yolkyolk
Ovalbumin mounts an attack and Ovalbumin mounts an attack and human immune system over human immune system over attacks.attacks.
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Health- Salmonella Health- Salmonella enteritidisenteritidis: Symptoms: Symptoms 6-72 hrs6-72 hrs Gastrointestinal IllnessGastrointestinal Illness 1:10,000 eggs w/ Salmonella1:10,000 eggs w/ Salmonella ““Hugging the toilet”Hugging the toilet”
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Health- Salmonella: Most Health- Salmonella: Most Susceptible Susceptible
Young & Old: WHY???Young & Old: WHY??? How does it spread???How does it spread??? SO:SO: Buy Refrigerated Buy Refrigerated Cook completely Cook completely
– 140ºF 5 min 140ºF 5 min – 160ºF 1 min.160ºF 1 min.
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Health- Salmonella: Safe Health- Salmonella: Safe AlternativeAlternative
Pasteurized @ 130-140ºFPasteurized @ 130-140ºF
Liquid eggsLiquid eggs
Dried whitesDried whites
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Health - CholesterolHealth - Cholesterol
1970’s-1980’s PHOBIA1970’s-1980’s PHOBIA
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Health – Cholesterol: Health – Cholesterol: Misconception Misconception
1 Lg egg: 215 mg = meat 50 mg1 Lg egg: 215 mg = meat 50 mg
Blood cholesterol Heart RiskBlood cholesterol Heart Risk
Blood cholesterol influenced by Blood cholesterol influenced by Saturated fatsSaturated fats. HOWEVER: most egg . HOWEVER: most egg yolks are yolks are unsaturated fatsunsaturated fats..
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Health – Cholesterol: Health – Cholesterol: SubstitutesSubstitutes REALREAL egg whites
Imitation yolk: Veggie Oil
Milk Solids
Gums
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Dissecting The EggDissecting The Egg
1.1. CuticleCuticle
2.2. ShellShell
3.3. WhitesWhites
4.4. YolkYolk
5. Chalaza5. Chalaza
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Dissecting the Egg- Cuticle/ColorDissecting the Egg- Cuticle/Color
Color due to proteinaceous Color due to proteinaceous cuticlecuticle
Cuticle plugs the poresCuticle plugs the pores Color has no relation to Taste or Color has no relation to Taste or
nutritional valuenutritional value Color relates literally…Color relates literally… Ex. Araucana hens lay blue Ex. Araucana hens lay blue
eggseggs
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Dissecting the Egg: ShellDissecting the Egg: Shell
Derived from Hen’s uterine lining Derived from Hen’s uterine lining cellscells
Shell composed of Calcium Shell composed of Calcium CarbonateCarbonate
10K10K
Air pocketsAir pockets
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Dissecting the Egg: ChalazaDissecting the Egg: Chalaza
2 chords that anchor the yolk2 chords that anchor the yolk
Will rotate while suspended in the Will rotate while suspended in the middle of the eggmiddle of the egg
Function: Provides stability & Function: Provides stability & cushioning cushioning
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Dissecting the Egg: Dissecting the Egg: YolkYolk
YOLK= YOLK= Fuel: ¾ calories, iron, thiamin, & Fuel: ¾ calories, iron, thiamin, & vitamin Avitamin A
Pigment Plant xanthophlls (from what hen Pigment Plant xanthophlls (from what hen ate) fat & protein synthesized in the ate) fat & protein synthesized in the hen’s liverhen’s liver
White Yolk: White Yolk: Yellow Yolk Yellow Yolk
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Dissecting the Egg: WhitesDissecting the Egg: Whites
Thick & Thin WhitesThick & Thin Whites Function: Function:
– defense against Infectiondefense against Infection– protection protection – nourishmentnourishment
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Whites: NourishmentWhites: Nourishment
ContainsContains Trace mineralsTrace minerals Fatty materialsFatty materials Vitamin (riboflavin)Vitamin (riboflavin) GlucoseGlucose Water - 90%Water - 90% Proteins - 10% Proteins - 10%
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Whites: DefensesWhites: Defenses Acts as the Acts as the primary primary defense against defense against
infection & predators infection & predators
Protein that blocks digestive enzymesProtein that blocks digestive enzymes
Protein binds to iron & vitamins so Protein binds to iron & vitamins so NOTNOT useful to other speciesuseful to other species
Protein inhibits virus reproductionProtein inhibits virus reproduction
Protein that digests bacteria cell wallProtein that digests bacteria cell wall
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Whites: The Proteins (4 total)Whites: The Proteins (4 total)
Ovotransferrin (1Ovotransferrin (1stst to coagulate) to coagulate)
Carries iron to developing chickCarries iron to developing chick Prevents bacteria from using ironPrevents bacteria from using iron
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Whites: The Proteins (4 total)Whites: The Proteins (4 total)
Ovalbumin (most plentiful - Ovalbumin (most plentiful - approximately 70%)approximately 70%)– Reactive sulfur groupsReactive sulfur groups
Ovomucin and Ovomucoid (less than Ovomucin and Ovomucoid (less than 2%)2%)– Jelly-like consistencyJelly-like consistency– Pulls together soupy proteins into Pulls together soupy proteins into
organized structure organized structure –
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Whites: Other ProteinsWhites: Other Proteins
Globulins – lysozymeGlobulins – lysozyme
Avidin – large quantities can Avidin – large quantities can cause biotin deficiencycause biotin deficiency
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Whites:Whites: Thick Thick & Thin= Albumen& Thin= Albumen
Adds Adds THICKTHICK layers to layers to the membrane whites the membrane whites (albumen) in 4 layers (albumen) in 4 layers for for THICK THICK & THIN & THIN albumen for albumen for consistency consistency
Secreted by Oviduct Secreted by Oviduct from protein secreting from protein secreting cells.cells.
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Eggcelent FactsEggcelent Facts Commercial chicken can lay 250-290 Commercial chicken can lay 250-290
eggseggs Raw eggs in shell keep for 3-5 weeks Raw eggs in shell keep for 3-5 weeks
in refrigeratorin refrigerator Egg consumption has declined from Egg consumption has declined from
320 eggs per person in 1967 to 235 in 320 eggs per person in 1967 to 235 in 1990 and has increased to 254 in 1990 and has increased to 254 in 2003.2003.
Weight - 15 to 30 oz.Weight - 15 to 30 oz. ¼ hen’s energy goes in to egg making¼ hen’s energy goes in to egg making
– ½ for a duck½ for a duck
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Good Egg Baddd EggGood Egg Baddd Egg
GradesGrades Thick Thick WhitesWhites
Firm Firm Round Round YolksYolks
AAAA YESYES YESYES
AA Less ThickLess Thick WeakerWeaker
BB Fast Fast spreadingspreading
Easily Easily BreaksBreaks
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Good Egg Baddd EggGood Egg Baddd Egg Characteristics of a Good Egg:Characteristics of a Good Egg:
– IntactIntact– Uncontaminated eggUncontaminated egg– Strong ShellStrong Shell– Firm YolkFirm Yolk– Thick WhiteThick White– HOW DO YOU KNOW W/O BREAKING HOW DO YOU KNOW W/O BREAKING
THE EGG?THE EGG?
– Bad eggs Normally when Hen lays eggs Bad eggs Normally when Hen lays eggs at the end of the laying yearat the end of the laying year
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Good Egg Bad Egg: CANDLINGGood Egg Bad Egg: CANDLING
Spots cracksSpots cracks Large air cellsLarge air cells ““Meat spots”Meat spots”
– Brown in whitesBrown in whites– Tissue slough off from Tissue slough off from
oviduct walloviduct wall Blood spots on yolkBlood spots on yolk
– Burst capillaries in hen Burst capillaries in hen ovary/yolk sacovary/yolk sac
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Eggs = A Hot Potato?Eggs = A Hot Potato? Eggs quickly gatheredEggs quickly gathered
Immediately CooledImmediately Cooled
(USA) Wash in warm water(USA) Wash in warm water
Sold 2 days afterSold 2 days after
Deterioration: 1 Day Room Temp = 4 Deterioration: 1 Day Room Temp = 4 Days in FridgeDays in Fridge
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Why?Why?
Whites & Yolks Whites & Yolks more alkaline more alkaline (dec. Acid)(dec. Acid)
Moisture Moisture decreasesdecreases
Calcium Calcium Carbonate Carbonate dissolvesdissolves
pH pH ThenThen
pH pH LaterLater
WhitesWhites 6.0 pH6.0 pH 6.6 pH6.6 pH
YolkYolk 7.7 pH7.7 pH 9.2 pH9.2 pH
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StorageStorage
FREEZING: Air tight containerFREEZING: Air tight container
Separate from shellSeparate from shell WhitesWhites YolksYolks
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Egg Versatility!Egg Versatility!
FryFry BoilBoil Deep FriedDeep Fried BakedBaked RoastedRoasted PickledPickled FermentedFermented
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Coagulation Coagulation
1. Egg proteins folded chains of Amino Acids
2. ADD Heat and chains UNFOLD
3. Unfolding and chains bond to each other for a continuous meshwork
1.
2.
3.
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Coagulation cont…Coagulation cont…
Egg white coagulation starts at Egg white coagulation starts at 144ºF and sets at 150ºF144ºF and sets at 150ºF
YolkYolk thickens at 150F and sets at thickens at 150F and sets at 158ºF158ºF
YolkYolk and white mixed set at 165ºF and white mixed set at 165ºF
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Eggs + Ingredients = Eggs + Ingredients = Coagulation?Coagulation?
LiquidLiquid - raises thickening temp - raises thickening temp
SugarSugar - raises thickening temp - raises thickening temp
Acid and saltAcid and salt - thickening and - thickening and coagulation at lower tempscoagulation at lower temps– Proteins do not have chance to unfold Proteins do not have chance to unfold
completely completely
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FoamFoam
Egg white filled with airEgg white filled with air Proteins unfold and bond together Proteins unfold and bond together
(whisking causes protein to unfold)(whisking causes protein to unfold) 4 stages4 stages
– ““foamy”foamy”– ““soft peak” soft peak” – ““stiff peak”stiff peak”– ““dry”dry”
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Foam cont.Foam cont. Other ingredientsOther ingredients
– SaltSalt - increases whipping - increases whipping time/decreases foam stabilitytime/decreases foam stability
– Sugar Sugar - delays foaming/reduces volume - delays foaming/reduces volume and lightness BUT improves stabilityand lightness BUT improves stability
– Egg yolk, oil/fatEgg yolk, oil/fat - interfere with foam - interfere with foam
Ex. Mousses, soufflés, angle food cake, and meringues. Foams help LIGHTEN a dish
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CustardsCustards
West: custards are milk or creamWest: custards are milk or cream Fruit & Veggies can cause Fruit & Veggies can cause
curdlingcurdling
EX. Crème Brûlée, Cheesecake, flan, & Quiche
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Green Eggs and HamGreen Eggs and Ham
Green Green yolks yolks areare
harmlesharmlesss
Ferrous Ferrous sulfide sulfide
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Power Point AuthorPower Point Author
Shauna HenleyShauna HenleyThe University of Vermont
Foods and NutritionBasic Concepts of Food