Transcript Eggcelent Eggs!! - Welcome to SchoolPage

Eggcellent Eggs!!
By Christina Story
Overview
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Egg Industry
Parts of the egg
Review of parts
Grades of eggs
Sizes of eggs
Review
Egg Industry
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In 2003 the United States produced
73.93 billion table eggs.
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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.
Let’s Learn
The Parts of the Egg
Shell
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Shell
Egg’s outer covering
9-12% of total weight
The shell is the egg’s 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.
Shell
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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.
Outer shell
membrane
Shell Membrane
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Inner and outer shell
Inner shell
membrane.
membrane
Protect against bacterial penetration
Air cell forms between the two
membranes.
Albumen
Albumen
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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
Air Cell
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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.
Germinal Disc
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The entrance leading into
the center of the yolk.
Germinal disc
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.
Chalaza
Chalaza
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Ropey strands of egg white
which anchor the yolk in place
in the center of the egg white.
Chalaza
The more prominent the chalaza, the fresher the
egg.
Does not need to be removed.
Vitelline Membrane
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Also known as the yolk
membrane.
Vitelline Membrane
Clear seal which holds egg yolk.
Protects the yolk from breaking.
Is weakest at the germinal disc and
weakens with age.
Yolk
Yolk
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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.
Let’s Review!!
Review of the Parts of an Egg
Albumen
Shell
Yolk
Air Cell
Outer Shell
Membrane
Inner shell membrane
Chalaza
Germinal Disc
Vitelline Membrane
Grading of Eggs
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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.
Exterior
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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.
Interior
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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.
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AA <1/8 inch air cell
A
>3/16 inch air cell
B
No limit on size of air cell
Sizing of Eggs
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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
At least
42 g
At least
49g
Large
Extra
Large
Jumbo
At least
63 g
70 g or
more
Weight
Less
than
42 g
At least
56 g
Let’s Review!
Review Questions
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Q: What determines the grade of an egg?
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Q: What are the grades of eggs?
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A: the candling or breakout method.
Q: What is the top egg producing state in the United States?
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A: weight in grams
Q: What are the methods for determining the interior quality for
grading?
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A: AA, A, B
Q: What determines the “size” of an egg?
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A: Interior and exterior quality
A: Iowa
Q: What is the per capita consumption of eggs in the US?
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A. 254.1 eggs per person
The END
Resources:
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www.ext.vt.edu/resources/4h/virtualfarm/
poultry/poultry_eggparts.html
http://www.eggs.ca/eggfacts/egggrade.asp
http://www.georgiaeggs.org/
www.unitedegg.org
www.aeb.org/learnmore/eggfacts.htm
Thank You!