EGG CHARACTERISTICS
4th Revision, 12 Nopember 2010
Nugraha E. Suyatma and Joko Hermanianto
Department of Food Science and Technology
Bogor Agricultural University
1
EGG
An egg is a round or oval cell laid by the
female of any number of different species,
consisting of an ovum surrounded by layers
of membranes and an outer casing, which
acts to nourish and protect a developing
embryo.
Which came first,
the chicken or the egg?
2
Edible egg:
•
•
•
•
•
•
•
Chicken egg
Quail egg
Duck egg
Goose egg
Ostrich egg
Turtle egg
Fish egg: roe and caviar
3
Commercial Egg:
• These are hen eggs in shell,
suitable for consumption in the
state, or use by food industries,
excluding broken eggs and
boiled eggs (CEE Regulation
No. 1907/90).
• Most laying hens are White
Leghorns .
4
Formation of the egg
• The egg is formed gradually over a period
of about 25 hours.
• The female chick (Hen) has up to 4000
tiny ova (reproductive cells), from some of
which full-sized yolks may develop when
the hen matures.
• Each yolk (ovum) is enclosed in a thinwalled sac, or follicle, attached to the
ovary
• The mature yolk is released when the sac
ruptures, and is received by the funnel of
the left oviduct
5
Section of oviduct
1 Funnel
(infundibulum)
2 Magnum
3 Isthmus
4 Shell gland
(uterus)
5 Vagina/cloaca
Approximate
Functions of section of oviduct
time egg spends
in this section
15 minutes
Receives yolk from ovary. If live sperm
present, fertilisation occurs here
(commercially produced table eggs are not
fertilised)
3 hours
Inner and outer shell membranes are added,
as are some water and mineral salts
1 hour
Albumen (white) is secreted and layered
around the yolk
21 hours
Initially some water is added, making the
outer white thinner. Then the shell material
(mainly calcium carbonate) is added. Pigments
may also be added to make the shell brown
less than 1
The egg passes through this section before
minute
laying. It has no other known function in the
egg’s formation
6
Video of the Hen and Egg Formation
7
Anatomy of an Egg
1. Eggshell
2. Outer membrane
3. Inner membrane
4. Chalaza
5. Exterior albumen
6. Middle albumen
7. Vitelline membrane
8. Nucleus of pander
9. Germinal disk
10.Yellow yolk
11.White yolk
12.Internal albumen
13.Chalaza
14.Air cell
15.Cuticula
8
9
10
Video of the Egg composition
11
SHELL (10 %)
• calcium carbonate (CaCO3) 94-97
%, 3-6 % Organic material and
Pigment
• Shell strength is depend on the
content of CaCO3, Mg, P, dan vit D
• Thickness: 0.2-0.4 mm
• Pores: 700 pores/cm2 = 17,000 tiny
pores
• Semipermeable membrane: air and
moisture can pass through has a
thin outermost coating called the
bloom or cuticle that helps keep out
bacteria and dust.
• Mucin : covered shell and pores
12
INNER AND OUTER
MEMBRANES AND AIR CELL
INNER AND OUTER MEMBRANES Lye between
the eggshell and egg white, these two transparent
protein membranes provide efficient defense
against bacterial invasion. If you give these layers
a tug, you’ll find they’re surprisingly strong.
They’re made partly of keratin, a protein that’s
also in human hair.
AIR CELL
• An air space forms when the contents of the egg
cool and contract after the egg is laid
13
ALBUMEN (60 %)
• The egg white is known as
the albumen, which comes
from albus, the Latin word
for “white.”
• contain approximately 40
different proteins:
• OVALBUMIN,
CANALBUMIN,
OVOTRANSFERIN,
LYSOZYM, OVOMUCIN,
AVIDIN, ETC
14
ALBUMEN
Consist of 4 parts:
inner thick, inner thin
white, outer thick white
dan outer thin white.
cloudy appearance due
to CO2 content.
15
Albumen
The egg white is approximately two-thirds of the total
egg's weight out of its shell with nearly 90% of that
weight coming from water.
Proteins
Lipids
9.7-10.6%, 0.03%
Carbohydrates Ash
0.4-0.9%
0.50.6%
Composition of Albumen (Powrie 1973)
Water
87.989.4%
16
MAJOR PROTEINS IN ALBUMEN OF TOTAL
PROTEINS (Powrie 1973)
Egg white contains approximately 40 different
proteins:
Ovalbumin
Conalbumin
Ovomucoid
Lysozyme
Globulins (G2, G3)
Ovomucin
54%
13%
11%
3.5%
8.0 %
1.5%
Other protein components include, flavoprotein (0.8%),
ovoglycoprotein (0.5%), ovomacroglobulin (0.5%),
ovoinhibitor (0.l%) and avidin (0.05%).
17
YOLK
• Less water, more protein and fat than the
white egg
• Contains most of the vitamins and
minerals of the egg, including Fe, vitamin
A, vitamin D, phosphorus, calcium,
thiamine, and riboflavin.
• Source of lecithin (emulsifier).
• Yolk color ranges from just a hint of
yellow to a magnificent deep orange,
according to the feed and breed of the hen.
• Umur: kuning telur mengabsorbsi air dari
albumen: ukuran kuning telur membesar ,
strukturnya meregang, membran vitelin
rusak, bentuk lebih flat.
18
CHALAZAE
AND VITELIN
CHALAZAE
• Opaque ropes of egg white, the chalazae
hold the yolk in the center of the egg. Like
little anchors, they attach the yolk’s casing
to the membrane lining the eggshell. The
more prominent they are, the fresher the
egg.
Vitelline Membrane
• The clear casing that encloses the yolk.
19
CHEMICAL COMPOSITION
OF EGG
20
Chemical composition of eggs
Animal
Water
(%)
Protein
(%)
Lipid
(%)
CHO
(%)
Ash
(%)
Chicken
73,7
12,9
11,5
0,9
1
Duck
70,4
13,3
14,5
0,7
1,1
Goose
70,4
13,9
13,3
1,5
Pigeon
72,8
13,8
12
0,8
0,9
Quail
73,7
13,1
11,1
1
1,1
Ostrich
72,6
13,1
11,8
1,7
0,8
Turtle
66,7
16,5
11,6
3,3
1,9
21
Composition of egg
Telur
Utuh
37
12,9
11,5
1,1
Putih
telur
87,6
10,9
1,1
Free Carbohydrate
0,3
0,4
0,2
-
Ash
Mineral
1
11,7
0,7
1
1,7
2
96
Component (%)
Water
Protein
Lipid
Carbohydrate
Kuning Kulit
telur
telur
51,1
16
4
30
1,1
-
22
Vitamin
contain most of the recognised vitamins
with the exception of vitamin C
23
VITAMINS
Component
Vitamin A
Vitamin D
Vitamin E
Amount per 100 g egg
190 µg
1,8 µg
1,1 mg
Vitamin C
Thiamin (B1)
Riboflavin (B2)
none
0,09 mg
0,47 mg
Niacin
Vitamin B6
Folate
Vitamin B12
0.1 mg
0.12 mg
50 µg
2,5 µg
Biotin
Panthotenic acid
20 µg
1.77 µg
24
Minerals
• Iodine  thyroid hormone
• Phosphorus  for bone health.
• Zinc  for wound healing, growth and fighting
infection
• Selenium  an important antioxidant
• Calcium  for bone and growth structure and
nervous function.
• also contain significant amounts of iron, the vital
ingredient of red blood cells.
25
Lipids in Yolk
• Egg lipids are found mostly in yolk, only 0,05% is
contained in albumen.
• Fatty acid content:
monounsaturated (46.5%) > saturated (37.5%) >
polyunsaturated (16.5%)
• Highest fatty acid content:
monounsaturated: oleic acid (18:1) approximately
40% from lipid total.
26
Fatty acid content in 100 g of fresh yolk
Fatty Acid
Saturated
Gram
1.59
Miristat (14:0)
0.02
Palmitat (16:0)
1.14
Stearat (18:0)
0.40
Monounsaturated
1.95
Palmitoleat (16:1)
0.15
Oleat (18:1)
1.78
Eicosenoat (20:1)
0.01
Polyunsaturated
0.70
Linoleat (18:2)
0.59
Linolenat (18:3)
0.02
Arakidonat (20:4)
0.07
Dokosaheksanoat (22:6)
0.02
Cholesterol
0.21
TOTAL
4.43
27
Chemical composition change:
Liquid /Dry
Egg
Liquid*/Frozen
Dried
(per100g)
Whole Eggs
Yolk
White
Whole Eggs
Yolk
Stabilized
White
SOLIDS-g
24.80
43.20
11.0
96.3
97.3
93.5
pH-g
7.8
6.7
8.8
8.7
6.5
6.8
PROTEIN-g
12.0
15.3
9.3
48.4
33.7
84.6
LIPIDS-g
9.71
23.0
0.076
39.2
52.9
0.407
FREE
GLUCOSE-g
<0.10
0.2
0.3
0.3
<0.1
0
ASH-g
0.80
1.4
0.4
3.4
3.3
3.6
MOISTURE-g
75.20
56.80
89.0
3.7
2.7
6.5
28
1. One medium egg contains between 4-5 grams of
fat
2. High cholesterol
•
~200 mg/egg
3. High in Complete Protein (EPR=93.7%); > milk
(84.5%), fish (76%), beef meat (74.3%), soy
bean (72.8%), corn (60%)
4. Little to no CHO
5. High in vitamins & minerals
•
Vitamins ADEK, some B vitamins, selenium, iodine,
29
zinc, iron, copper
Energy value of eggs
• 78 kilocalories (324 kilojoules)
• only around 3% of the average energy
requirement of an adult man and 4% for an
adult woman.
Protein
• 12.5% of the weight of the egg in both the yolk
and the albumen.
• Egg protein is of high biological value as it
contains all the essential amino acids needed by
the human body.
30
1.
2.
3.
4.
5.
6.
Functional Properties of Egg
Flavor, color, nutrition
Foaming agent
Emulsifying agent
Aids in thickening/structure
Binding/coating agent
Leavening agent
31
FOAMING PROPERTIES
1.
2.
3.
4.
•
Air trapped in a liquid
In egg foam, air trapped by
protein.
Denatured and then
coagulates
Heat expands protein/air
Important to souffles,
meringues, omelet, and
sponge cake.
32
EMULSIFIER CAPACITY
 Egg yolk is a source of lecithin, an emulsifier and
surfactant.
 Lechitin is a substance that helps an emulsion form,
or helps keep an emulsion from separating
 Aplication :
• Mayonnaise
• butter sauces
• salad dressing
• Stabilizer of bakery products
• Whipped egg
33
Properties
Application
Thickening
Eggs thicken foods like custards puddings, sauces,
and creamy fillings
Leavening
Souffles, sponge & butter cakes, quick breads, and
puffy omelets are leavened by eggs
Coating
Meat dishes, breads, and cookies are some foods
with egg components as the base ingredients for
coatings
Binding
Eggs bind other ingredients for making meat loaves,
casseroles, and croquettes
Emulsifying
Eggs prevent mixture separation in mayonnaise,
salad dressing, and cream puff filling
Clarifying
Tiny particles are coagulated in soups and coffee to
create a clear solution
Retarding
Crystallization
Crystallization of sugar is slowed in cake icings and
candies
34
ANTIMICROBIAL AND
ALERGEN ON ALBUMIN
• LYSOZYME
• Immunoglobulin E (IgE)
memicu histamin
• OVOMUCIN (hambat enzim
tripsin)
• AVIDIN: mengkompleks biotin
(Avidin+Biotin komplek):
Biotin tak dpt dicerna
35
Daily Needed
Nutritional analysis of egg
without its shell
Constituent of Egg
Weight
For a medium egg (Av 58g)
Amount
per egg
1
% of Reference Nutrient
Intake (RNI)
Amount per
100g egg
For adult
female 19-50
years
For adult
male19-50
years
51.6
-
-
100.0
Water
g
38.8
-
-
75.1
Energy
kjoules/
kcalories
324/78
4
3
627/151
Protein
g
6.5
14
12
12.5
Carbohydrate
g
trace
-
-
trace
Fat
g
5.8
**
**
11.2
Inc saturated f.a.
g
1.7
**
**
3.2
Monounsaturated
f.a
g
2.3
**
**
4.4
Polyunsaturated
fa.t
g
0.9
**
**
1.7
36
Benefit of Egg Components
• Sialic acid could prevent infection
• Immunoglobulin in yolk can play a role as
antibody.
• PHOSVITIN has a function as food antioxidant.
• Choline: aids brain function and enhances
thinking capacity and memory. It is an important
part of a neurotransmitter that helps preserve the
integrity of the electrical transmission across the
gaps between nerves.
• Lutein and zeaxanthin: contribute to improving
eye health and protecting eyes from ultraviolet 37
rays
Allergen in Egg
• There are 4 proteins in egg white may provoque
an allergy:
- ovomucoid (11%)
- ovalbumin (54%)
- ovotransferrin (12%)
- lysozyme (3.5%)
38
Egg Allergy Symptoms
 Egg allergy is like most food allergy reactions: It usually
happens within minutes to hours after eating eggs.
• the skin - in the form of red, bumpy rashes (hives),
eczema, or redness and swelling around the mouth
• the gastrointestinal tract - in the form of belly cramps,
diarrhea, nausea, or vomiting
• the respiratory tract - symptoms can range from a runny
nose, itchy, watery eyes, and sneezing to the triggering of
asthma with coughing and wheezing
39
EGG QUALITY
40
Egg Quality


Exterior egg quality – shell quality based on shell
cleanliness, shell soundness, shell texture, shell
shape.
Interior egg quality – based on relative viscosity of
the albumen, freedom from foreign matter in the
albumen, shape and firmness of the yolk, and
freedom from yolk defects.
41
Shape Index of Egg
Ideal shape (USDA)
Shape index of egg = A/B x 100
A = the biggest diameter (cm)
B = The longest of length (cm)
42
Candling
• Candling is the process of holding a
strong light above or below the egg
to observe:
• cracks, checks and weak shells
• blood or meat spots.
• Egg air cell
• size of yolk and its movement
• double yolk, yolkless, etc.
• Become familiar with interior
quality.
43
44
45
46
47
Video: Candling an egg
48
Egg Grading
size
Grade
49
Sizing
Peewee:
less than 42 g
Small:
at least 42 g
Medium:
at least 49 g
Large:
at least 56 g
Extra Large:
at least 64 g
Jumbo:
at least 70 g
50
• Sizing is not related to grading in any way.
• Eggs are sold in cartons by various sizes determined by a
minimum weight for a dozen eggs in their shell.
51
Grading
Break Out
Appearance
Albumen
Appearance
Yolk
Appearance
Shell
Appearance
Usage
Grade AA
Covers a small area.
Grade A
Covers a moderate
area.
White is thick and
White is reasonably
stands high; chalaza thick, stands fairly
prominent.
high; chalaza
prominent.
Yolk is firm, round
Yolk is firm and
and high.
stands fairly high.
Approximates usual shape; generally clean,*
unbroken; ridges/rough spots that do not
affect the shell strength are permitted.
Grade B
Covers a wide area.
Small amount of thick
white; chalaza small or
absent. Appears weak and
watery.
Yolk is somewhat flattened
and enlarged.
Abnormal shape; some
slight stained areas
permitted; unbroken;
pronounced ridges/thin
spots permitted.
Ideal for any use, but Ideal for any use, but Good for scrambling,
are especially
are especially
baking, and as an ingredient
desirable for
desirable for
in other foods.
poaching, frying and poaching, frying and
52
cooking in shell.
cooking in shell.
Grading
GRADE A: sold at
retail store




GRADE B : only a
GRADE C: not sold at
small percentage sold retail stores; all go to
yolk is round, well at retail stores; most further processing
go to further
market
centred
processing market

yolk is enlarged or
white is thick

yolk is slightly
flattened
small air cell (less
enlarged or

white is thin and
than 5 mm deep)
flattened
watery
shell is clean,

white is moderately  shell may be
uncracked and of
thin
cracked and stained
normal shape

shell uncracked
53
Video: EXTERIOR EGG QUALITY
54
Grade
Grade Grade AA egg covers small area and
stands high; white is thick and firm; yolk is
high and round.
Grade A egg covers moderate area; white is
reasonably firm and stands fairly high; yolk is
high.
There are three consumer grades for eggs: U.S. Grade AA, A,
and B. The grade is determined by the interior quality of the
egg and the appearance and condition of the egg shell. Eggs
55
of any quality grade may differ in weight (size).
Video: BROKEN OUT EGG QUALITY
56
Egg White Index
• Egg white index (EWI)
Height of thick albumen
EWI =
diameter of thick albumen
(longest+shortest)/2
Newlaid Egg has the value: 0.050 – 0.174
Good quality if the value: 0,090 – 0,120
57
Egg Yellow Index (EYI)
height of yolk
EYI =
diameter of yolk
Good quality if EYI : 0,33 – 0,50
Average value: 0.42.
58
Haugh Unit
• Haugh unit (HU)
HU= 100 log [h-(√G(3w0.37-100)+1,9]
100
HU= Haugh unit
h = heigh of thick albumen (mm)
G= 32,2
w= whole egg weight (g)
Fresh egg: HU=100
Good quality: HU = 75; acceptable until 50
Bad quality (Spoiled egg): HU < 50
59
Changes in quality as the egg ages
60
Egg Handling
• Egg quality is affected by temperature and
relative humidity of storage room.
• Need to preservation
Egg preservation principles:
• Avoid spoilage microorganisme enter
• Minimize the loss of water and gas from egg.
Aplication:
• freezing, chilling, dry packaging, coating with
essential oil, dipping in various liquid.
61
62
63
Video: Commercial Egg Production
64
Video: Egg Processing
65
Commercial Egg Production and
Processing
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
66
Egg Production



The objective of this presentation is to provide a general
overview of commercial egg production and processing.
The slides are ordered in a sequential series as they occur
in the production cycle.
This particular egg production facility is considered an “inline” operation. This means the eggs are produced and
packaged for shipping to retail markets on the farm. There
are also many “off-line” operations that produce eggs in
one location and transport them to another location for
processing.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
67
On the horizon is an in-line commercial egg production facility.
This facility is vertically integrated or self-contained, i.e., the
company owns the feed mill, hens, buildings, egg processing facility,
and transportation vehicles.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
68
B
A
A
A
This facility represents one level of vertical integration, the feed
mill. Based on demand, raw grains (from bins “A”) are mixed into
designated poultry rations and augured (“B”) to the layer houses.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
69
C
C
The auger system delivers grain into high-rise layer houses (“C”).
These houses are approximately 500 feet long and may contain as
many as 150,000 laying hens.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
70
B
B
A
B
B
This is a view of the inside of a layer facility. Hens are housed on
slanted wire-mesh floors. Nipple waterers (“A”) serve as the hen’s
source of water and the feed is transported through the house via an
auger system in feeders (“B”).
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
71
This is another view of the egg transporting mechanisms within a
layer house. The use of advanced mechanical engineering has
greatly reduced the occurrence of human egg handling to the
point that eggs are rarely touched by human hands.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
72
DD
D
As the eggs reach the end of each level, automatic collectors place the
eggs into plastic egg handlers (“D”). Plastic egg handlers carry the
eggs directly to the egg processing facility via a large overhead belt.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
73
These eggs are traveling to the egg processing/breaker facility.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
74
E
E
Eggs are mechanically washed with a mild detergent and sanitized
(“E”). Eggs are washed in 120oF water.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
75
Here the eggs are entering the first stage in the egg grading process.
The eggs are evaluated by an automated computerized detection
system. Eggs are graded into categories of AA, A, B, and Loss
Quality Standards.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
76
Brushes transport eggs away from the egg graders to the
packaging area of the plant. It is at this point that eggs will
either be placed into cartons or be sent to the breakers.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
77
This is a view of the entire “carton line.” Each stack of cartons
(blue, white, yellow, pink) represents a different egg size.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
78
Eggs are mechanically placed into cartons for shipping to the
grocery market.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
79
Eggs awaiting processing within the plant are placed on
plastic skids. These skids are washed and sanitized on a
daily basis.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
80
On the left, eggs are stacked in cardboard flats for shipment to the
retail market. Eggs on the right are stacked in plastic flats and are
awaiting transfer to the egg further processing (breaker) room.
Again, plastic is used inside the plant for sanitation and recycling
purposes.
81
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
82
This is an egg breaker machine. This machine cracks the egg
shells and separates the yolk (yellow) from the albumen (white).
The separation process works exactly like a household egg
strainer. This machine will process 18,000 eggs per hour.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
83
This is also egg breaker machine. However, this machine will
process 500,000 eggs per hour.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
84
Video: Egg Breaker
85
Video: Egg Breaker
86
These are bulk bins full of pasteurized egg yolks awaiting
shipment. Egg pasteurization occurs at 145oF for seven
minutes for 3,000 pounds of egg.
87
Processed egg products leave the facility via 1/2 gallon
“milk” cartons, bagged product, and bulk semi-trailers.
Processed egg products also include hard-boiled eggs.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
88
Eggshells are processed in the plant. The shells have been
dried and ground for use in animal feeds and other products.
Courtesy of Ryan A. Meunier & Dr. Mickey A. Latour; Purdue University
89
TERIMAKASIH
90
QUIZ TIME..
TULISKAN NAMA DAN NRP ANDA !
******************************
SUKSES ITU LAHIR DARI KEJUJURAN, KEULETAN
DAN KETEKUNAN YANG DIIRINGI DENGAN DOA
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