3.1 Eggs 🍳 Flashcards
▪ produced commercially on farms with a few hundred laying chickens by small and micro-sized backyard poultry
▪ chicken, ducks, quails, turkeys, geese, guinea fowls, gulls, pigeon, pheasants and ostriches
Eggs
▪ accounts for about 9-12% of its total
weight
▪ first line of defense against bacterial
contamination
Shell
▪ produced by the shell gland (uterus) of the oviduct
▪ has an outer coating, the bloom or
cuticle
▪ contain thousands of small pores
True
▪ reduces moisture losses and prevents bacterial penetration of the egg shell
cuticle
▪ composed of __________ (94%) with small amounts of magnesium, carbonate, calcium phosphate, and other inorganic matter
calcium carbonate
▪ as the hen ages, egg size increases
True
▪ shell color indicates the breed of the hen but has no bearing on the nutrient content or taste
True
▪ located underneath the shell that sticks to the shell
outer membrane
▪ egg membrane that sticks to the albumen
inner membrane
▪ covering that protects the yolk from breaking; weakest at the germinal disc and tends to become more fragile as the egg ages
vitelline membrane
▪ an empty space between the white and shell at the large end of the egg which is barely existent in newly laid egg
▪ appears as flat disk at the large end of a hard cooked egg
air cell
▪ ______ eggs have ______ egg cells
because as the egg ages, moisture and
carbon dioxide leave through the pores
of the shell, air enters to replace them
and the air cell becomes larger
older ; larger
▪ air cell moves freely upward the uppermost point of the egg when rotated
free or floating air cell
▪ results in one or more small separate air bubble floating beneath the main air cell
bubbly air cell
▪ accounts for about 67% of egg’s weight
▪ produced by the oviduct and consists of four alternating layers of thick and thin consistencies
Albumen/ Egg white
▪ a narrow fluid layer enclosed by the inner shell membrane
outer thin white
▪ a gel that forms the center of the albumen
outer thick white
▪a fluid layer located next to the yolk
inner thin white
▪a dense, matted, fibrous capsule of albumen around the vitelline of the yolk
inner thick white
▪ the more viscous consistency of the thick albumen is due to the higher
concentration of the protein _________
ovomucin
▪ has a fibrous character and contributes significantly to the gel-like structure of the thick white
ovomucin
▪ contains more than half the egg’s total protein, niacin, riboflavin, chlorine,
magnesium, potassium, sodium, and
sulfur
True
▪ cloudy appearance comes from
__________
carbon dioxide
▪ __________ escapes as the egg
ages leading to a more transparent
appearance in old eggs
carbon dioxide
▪ loss of carbon dioxide accounts for the increase in ________ as manifested by an increase in pH near neutrality
alkalinity
▪ increase in pH degrades the ________ in egg albumen affecting the viscosity and resulting to thinning out
ovomucin
▪ a germicidal agent in egg white
lysozyme
▪ has the ability to bind divalent and trivalent metallic ions depriving bacteria
conalbumin
▪it binds with biotin and easily denatured when cooked
avidin
▪ foams and increases in volume _____ times when beaten vigorously
6-8 times
▪ the yellow to orange-yellow portion that makes up about 33% of the liquid weight of egg
▪ originated from an Indo-European word that means “bird” and the Old English for “yellow”
Yolk
▪ contains all of the fat in the egg and has little less than half of the protein
Yolk
▪ main protein/ lipoprotein in egg yolk 🐣
vitellin
▪high in phosphorus and has antioxidant properties
phosvitin
▪ high in sulfur
livetin
▪responsible for the yolk’s emulsifying properties
lecithin and monoglycerides
▪ 🪢 ropey strands of egg white at both ends of the egg, which anchor the yolk in place in the center of the thick white
chalaza
▪ the prominent the chalazae, the fresher the egg
True
▪ this is the entrance of the latebra, the channel leading to the center of the yolk
germinal disc
▪ requires an egg processing plants be inspected and that their eggs and egg products be wholesome, unadulterated, and truthfully labeled
Egg Products Inspection Act of 1970
▪ Eggs that do not pass inspection, called ________ eggs, are not allowed to be sold whole to the consumer.
restricted eggs
▪ eggs with cracked shells
checks ♟️
▪ have cracked shells and broken membranes
leakers
▪ have at least ¼ of their shell covered with dirt or stain
dirties
▪have greenish egg whites or are fertilized, rotten, moldy, or bloody
inedibles
▪ occur in <1% of eggs that have small blood spots 🩸
meat spots
Grading
USDA Grade AA
▪ an easy, simple way to know if the egg is fresh or old
▪ when an egg floats, it is not fresh because the air cell has enlarged making the egg less dense
▪ fresh eggs will sink to the bottom under water
Floating Test
▪ if the image of the yolk is hard to see, the egg is still fresh because the albumen is still thick enough to hide the yolk🔦
▪ if the yolk is seen easily, it means that it is mobile and is moving
close to the shell
Egg candling
▪ suggested by Raymond Haugh in 1937
▪ a unit for describing egg freshness based on the thickness of the
albumen
▪ the egg is brought within a specific temperature range, weighed,
and broken onto a flat plate
Haugh Unit
▪ a tripod micrometer is used to measure the _______ of the albumen
height
▪ excellent = _____ or above;
▪ acceptable = _____;
▪ and lack of freshness = _____
▪ 90
▪ 70
▪ <60
Sizing: 70g above
Size Jumbo
Sizing 65-69g
Size Extra Large
Sizing 60-64g
Size Large
Sizing 55-64g
Size Medium
Sizing 50-54g
Size Small
Sizing 40-49g
Size Peewee
Sizing <40g
Reject
Has a blastoderm
Fertile eggs
hens that have access to outdoor areas
Free-range
hends fed with feed without pesticides, fertilizers, herbicides, fungicides
Organic
eggs are richer due to triple the cholesterol content (619g) and double the fat (10g)
Duck eggs
higher in cholesterol (1227mg) and (19g) fat
Goose eggs
largest of all eggs and weighs about 3 pounds approx 6 inches long and 5 inches wide
Ostrich eggs
a germicidal agent
lysozyme
dainty, delicate eggs are often hard-boiled and used as gourmet garnishes or salad ingredients
Quial eggs
usually lays 1 egg every 3 days
Turkey
ability to bind divalent and trivalent metallic ions depriving bacteria
conalbumin
binds with biotin and easily denatured when cooked
avidin
denatures easily
ovalbumin
inhibits enzyme (trypsin)
ovomucoid
main protein in egg yolk
vitellin
