1 EGGS!

2 What were doing today folks! History History Etiology Etiology Health Health Dissecting the egg Dissecting the egg Good Egg, Bad Egg Good Egg, Bad Egg Cooking Cooking

3 Background History 300 mya- eggs laying in the ocean 300 mya- eggs laying in the ocean 100 mya- mineralized egg shell 100 mya- mineralized egg shell 8 mya- Gallus genus formed 8 mya- Gallus genus formed 3-4 mya- Gallus gallus chicken species formed 3-4 mya- Gallus gallus chicken species formed 7500 BCE domestication SE Asia 7500 BCE domestication SE Asia

4 Background History Egg + Sperm = Fertilization -> Egg + Sperm = Fertilization -> Egg + no sperm = Egg + no sperm =

5 Health - Allergies Cause from ovalbumin NOT the yolk Cause from ovalbumin NOT the yolk Ovalbumin mounts an attack and human immune system over attacks. Ovalbumin mounts an attack and human immune system over attacks.

6 Health- Salmonella enteritidis : Symptoms 6-72 hrs 6-72 hrs Gastrointestinal Illness Gastrointestinal Illness 1:10,000 eggs w/ Salmonella 1:10,000 eggs w/ Salmonella Hugging the toilet Hugging the toilet

7 Health- Salmonella: Most 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 –160ºF 1 min.

8 Health- Salmonella: Safe Alternative ºF ºF Liquid eggs Liquid eggs Dried whites Dried whites

9 Health - Cholesterol 1970s-1980s PHOBIA 1970s-1980s PHOBIA

10 Health – Cholesterol: Misconception 1 Lg egg: 215 mg = meat 50 mg 1 Lg egg: 215 mg = meat 50 mg Blood cholesterol Heart Risk Blood cholesterol Heart Risk Blood cholesterol influenced by Saturated fats. HOWEVER: most egg yolks are unsaturated fats. Blood cholesterol influenced by Saturated fats. HOWEVER: most egg yolks are unsaturated fats.

11 Health – Cholesterol: Substitutes REAL REAL egg whites Imitation yolk: Veggie Oil Milk Solids Gums

12 Dissecting The Egg 1. Cuticle 2. Shell 3. Whites 4. Yolk 5. Chalaza 5. Chalaza

13 Dissecting the Egg- Cuticle/Color Color due to proteinaceous cuticle Color due to proteinaceous cuticle Cuticle plugs the pores Cuticle plugs the pores Color has no relation to Taste or nutritional value Color has no relation to Taste or nutritional value Color relates literally… Color relates literally… Ex. Araucana hens lay blue eggs Ex. Araucana hens lay blue eggs

14 Dissecting the Egg: Shell Derived from Hens uterine lining cells Derived from Hens uterine lining cells Shell composed of Calcium Carbonate Shell composed of Calcium Carbonate 10K 10K Air pockets Air pockets

15 Dissecting the Egg: Chalaza 2 chords that anchor the yolk 2 chords that anchor the yolk Will rotate while suspended in the middle of the egg Will rotate while suspended in the middle of the egg Function: Provides stability & cushioning Function: Provides stability & cushioning

16 Dissecting the Egg: Yolk YOLK= Fuel: ¾ calories, iron, thiamin, & vitamin A YOLK= Fuel: ¾ calories, iron, thiamin, & vitamin A Pigment Plant xanthophlls (from what hen ate) fat & protein synthesized in the hens liver Pigment Plant xanthophlls (from what hen ate) fat & protein synthesized in the hens liver White Yolk: Yellow Yolk White Yolk: Yellow Yolk

17 Dissecting the Egg: Whites Thick & Thin Whites Thick & Thin Whites Function: Function: – defense against Infection – protection – nourishment

18 Whites: Nourishment Contains Contains Trace minerals Trace minerals Fatty materials Fatty materials Vitamin (riboflavin) Vitamin (riboflavin) Glucose Glucose Water - 90% Water - 90% Proteins - 10% Proteins - 10%

19 Whites: Defenses Acts as the primary defense against infection & predators Acts as the primary defense against infection & predators Protein that blocks digestive enzymes Protein that blocks digestive enzymes Protein binds to iron & vitamins so NOT useful to other species Protein binds to iron & vitamins so NOT useful to other species Protein inhibits virus reproduction Protein inhibits virus reproduction Protein that digests bacteria cell wall Protein that digests bacteria cell wall

20 Whites: The Proteins (4 total) Ovotransferrin (1 st to coagulate) Ovotransferrin (1 st to coagulate) Carries iron to developing chick Carries iron to developing chick Prevents bacteria from using iron Prevents bacteria from using iron

21 Whites: The Proteins (4 total) Ovalbumin (most plentiful - approximately 70%) Ovalbumin (most plentiful - approximately 70%) –Reactive sulfur groups Ovomucin and Ovomucoid (less than 2%) Ovomucin and Ovomucoid (less than 2%) –Jelly-like consistency –Pulls together soupy proteins into organized structure –

22 Whites: Other Proteins Globulins – lysozyme Globulins – lysozyme Avidin – large quantities can cause biotin deficiency Avidin – large quantities can cause biotin deficiency

23 Whites: Thick & Thin= Albumen Adds THICK layers to the membrane whites (albumen) in 4 layers for THICK & THIN albumen for consistency Adds THICK layers to the membrane whites (albumen) in 4 layers for THICK & THIN albumen for consistency Secreted by Oviduct from protein secreting cells. Secreted by Oviduct from protein secreting cells.

24 Eggcelent Facts Commercial chicken can lay eggs Commercial chicken can lay eggs Raw eggs in shell keep for 3-5 weeks in refrigerator Raw eggs in shell keep for 3-5 weeks in refrigerator Egg consumption has declined from 320 eggs per person in 1967 to 235 in 1990 and has increased to 254 in Egg consumption has declined from 320 eggs per person in 1967 to 235 in 1990 and has increased to 254 in Weight - 15 to 30 oz. Weight - 15 to 30 oz. ¼ hens energy goes in to egg making ¼ hens energy goes in to egg making –½ for a duck

25 Good Egg; Badddd Egg

26 Good Egg Baddd Egg Grades Thick Whites Firm Round Yolks AAYESYES A Less Thick Weaker B Fast spreading Easily Breaks

27 Good Egg Baddd Egg Characteristics of a Good Egg: Characteristics of a Good Egg: –Intact –Uncontaminated egg –Strong Shell –Firm Yolk –Thick White – HOW DO YOU KNOW W/O BREAKING THE EGG? –Bad eggs Normally when Hen lays eggs at the end of the laying year

28 Good Egg Bad Egg: CANDLING Spots cracks Spots cracks Large air cells Large air cells Meat spots Meat spots –Brown in whites –Tissue slough off from oviduct wall Blood spots on yolk Blood spots on yolk –Burst capillaries in hen ovary/yolk sac

29 Eggs = A Hot Potato? Eggs quickly gathered Eggs quickly gathered Immediately Cooled Immediately Cooled (USA) Wash in warm water (USA) Wash in warm water Sold 2 days after Sold 2 days after Deterioration: 1 Day Room Temp = 4 Days in Fridge Deterioration: 1 Day Room Temp = 4 Days in Fridge

30 Why? Whites & Yolks more alkaline (dec. Acid) Whites & Yolks more alkaline (dec. Acid) Moisture decreases Moisture decreases Calcium Carbonate dissolves Calcium Carbonate dissolves pH Then pHLaterWhites 6.0 pH 6.6 pH Yolk 7.7 pH 9.2 pH

31 Storage FREEZING: Air tight container FREEZING: Air tight container Separate from shell Separate from shell Whites Whites Yolks Yolks

32 Egg Versatility! Fry Fry Boil Boil Deep Fried Deep Fried Baked Baked Roasted Roasted Pickled Pickled Fermented Fermented

33 Coagulation Egg proteins folded chains of Amino Acids ADD Heat and chains UNFOLD Unfolding and chains bond to each other for a continuous meshwork

34 Coagulation cont… Egg white coagulation starts at 144ºF and sets at 150ºF Egg white coagulation starts at 144ºF and sets at 150ºF Yolk thickens at 150F and sets at 158ºF Yolk thickens at 150F and sets at 158ºF Yolk and white mixed set at 165ºF Yolk and white mixed set at 165ºF

35 Eggs + Ingredients = Coagulation? Liquid - raises thickening temp Liquid - raises thickening temp Sugar - raises thickening temp Sugar - raises thickening temp Acid and salt - thickening and coagulation at lower temps Acid and salt - thickening and coagulation at lower temps –Proteins do not have chance to unfold completely

36 Foam Egg white filled with air Egg white filled with air Proteins unfold and bond together (whisking causes protein to unfold) Proteins unfold and bond together (whisking causes protein to unfold) 4 stages 4 stages –foamy –soft peak –stiff peak –dry

37 Foam cont. Other ingredients Other ingredients – Salt - increases whipping time/decreases foam stability – Sugar - delays foaming/reduces volume and lightness BUT improves stability – Egg yolk, oil/fat - interfere with foam Ex. Mousses, soufflés, angle food cake, and meringues. Foams help LIGHTEN a dish

38 Custards West: custards are milk or cream West: custards are milk or cream Fruit & Veggies can cause curdling Fruit & Veggies can cause curdling EX. Crème Brûlée, Cheesecake, flan, & Quiche

39 Green Eggs and Ham Green yolks are Green yolks are harmless harmless Ferrous sulfide Ferrous sulfide

40 Power Point Author Shauna Henley Shauna Henley The University of Vermont Foods and Nutrition Basic Concepts of Food