Eggcellent Eggs!!

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Eggcellent Eggs!!

• By Christina Story

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Overview

• Egg Industry
• Parts of the egg
• Review of parts
• Grades of eggs
• Sizes of eggs
• Review

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Egg Industry

• In 2003 the United States produced
  73.93 billion table eggs.
• 2003 per capita consumption was
  254.1 eggs.
• High point in per capita egg
  consumption was 402 eggs in 1945.
• Top egg producing state is Iowa
  with 44,271 layer hens.
• California is ranked 5 with 20,073
  layer hens.

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Lets Learn The Parts of the Egg
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Shell
Shell

• Eggs outer covering
• 9-12 of total weight
• The shell is the eggs first defense against
  bacterial contamination
• Made of mostly calcium carbonate
• Shell strength is determined by a hens diet
  (particularly calcium) and thickness by a hens
  age.

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Shell

• Each egg has up to 17,000
  pores on the shell surface. A greater number are
  on the larger end.
• Pores allow moisture and CO2 to move out and air
  to move in to form the air cell.
• A protective covering called the cuticle or the
  bloom covers the shell to block the pores to keep
  egg fresh and prevent contamination.

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Shell Membrane
Outer shell membrane

• Inner and outer shell
• membrane.
• Protect against bacterial penetration
• Air cell forms between the two membranes.

Inner shell membrane
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Albumen
Albumen

• Also known as egg white.
• Contains more than half the eggs total
  protein, potassium and sodium.
• More opalescent that white.
• Cloudy appearance comes from CO2 which escapes as
  the egg ages, so older eggs are clearer than
  fresh eggs.
• Tends to thin out with age.

Albumen
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Air Cell
Air Cell

• Empty space between the
  albumen and the shell.
• At the large end of the egg.
• When egg is first laid it is warm, as it cools,
  the content contracts and the inner shell
  membrane separates from the outer shell membrane
  forming the air cell.
• Air cell becomes larger with age
• Size of air cell is used in determining grade of
  egg.

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Germinal Disc

• The entrance leading into
• the center of the yolk.
• Slight depression on the yolk
• If the egg were to be fertilized-the sperm would
  enter through the germinal disc.
• Where the females genetic material is found.

Germinal disc
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Chalaza
Chalaza

• Ropey strands of egg white
  which anchor the yolk in place
  in the center of the egg white.
• The more prominent the chalaza, the fresher the
  egg.
• Does not need to be removed.

Chalaza
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Vitelline Membrane

• Also known as the yolk
• membrane.
• Clear seal which holds egg yolk.
• Protects the yolk from breaking.
• Is weakest at the germinal disc and weakens with
  age.

Vitelline Membrane
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Yolk
Yolk

• Yellow portion of egg.
• 33 of the liquid weight of the egg.
• Contains all of the fat in the egg and a little
  less than half of the protein.
• Contains more vitamins than the egg white.
• The yolk is a source of food for the embryo.

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Lets Review!!
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Review of the Parts of an Egg
Albumen
Shell
Yolk
Air Cell
Outer Shell Membrane
Chalaza
Inner shell membrane
Germinal Disc
Vitelline Membrane
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Grading of Eggs

• Grade is determined by interior and exterior egg
  quality.
• Grade is designated by letters AA, A, B.
• AA is the best grade.
• There is no nutritional difference between the
  grades.
• Most B grades are used by institutional egg users
  and never make their way to the grocery store.

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Exterior

• The shell is checked for cleanliness, strength,
  texture and shape. Higher grades must be clean.
• Cracks or unsound shells are restricted eggs.
• Shell should be oval with one end larger than the
  other.
• Thin spots or rough areas may be permitted under
  B grade of egg.

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Interior

• Candling method or the breakout method is used.
• Albumen judged based on clarity and firmness.
  Should be clear of discolorations or foreign
  bodies. Twirling an egg before a candling light
  will show the thickness of the albumen by
  observing how fast the yolk moves.
• The yolk is graded on distinctness of outline and
  absence of defects such as a blood spot.
• Higher grade eggs have a shallow air cell.
• AA lt1/8 inch air cell
• A gt3/16 inch air cell
• B No limit on size of air cell

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Sizing of Eggs

• Egg size is determined by weight.
• Each carton contains eggs of similar weights.
• Grade quality and weight are not related.
• 6 sizes of eggs

Size
Pee Wee Small Medium Large Extra Large Jumbo
Weight
Less than 42 g At least 42 g At least 49g At least 56 g At least 63 g 70 g or more
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Lets Review!
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Review Questions

• Q What determines the grade of an egg?
• A Interior and exterior quality
• Q What are the grades of eggs?
• A AA, A, B
• Q What determines the size of an egg?
• A weight in grams
• Q What are the methods for determining the
  interior quality for grading?
• A the candling or breakout method.
• Q What is the top egg producing state in the
  United States?
• A Iowa
• Q What is the per capita consumption of eggs in
  the US?
• A. 254.1 eggs per person

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The END
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Resources

• www.ext.vt.edu/resources/4h/virtualfarm/poultry/po
  ultry_eggparts.html
• http//www.eggs.ca/eggfacts/egggrade.asp
• http//www.georgiaeggs.org/
• www.unitedegg.org
• www.aeb.org/learnmore/eggfacts.htm
• Thank You!