Egg and Egg Cookery

EGG: NUTRITIONAL VALUE

 The composition of the egg is greatly influenced by the hen’s diet
 Feeding high levels of polyunsaturated fats will produce eggs also high in
polyunsaturated fats which lower serum cholesterol.
 The vitamin content of the egg is also influenced by the feed given to the hen.
High Vitamin A is often associated with the deep-colored yolks.
 Only 27% of the fat in egg is saturated fat that contains LDL cholesterol (bad
cholesterol).
 A 2007 study of nearly 10,000 adults demonstrated no correlation between moderate (6
per week) egg consumption and cardiovascular disease or strokes, except in the
subpopulation of diabetic patients who presented an increased risk of coronary heart
disease.
 Egg yolk is high in CHOLESTEROL (About 218 mg per egg weighing 50 grams), but egg
white has no cholesterol.
 The dietary cholesterol intake recommended for Filipinos is 300 mg per day.
 People on a low-cholesterol diet may need to reduce egg consumption or just use egg
whites.
 One of the dietary concerns is ALLERGIES, particularly in EGG WHITES which are the
most common food allergy in children.
 Thus, eggs are introduced to their diet after 6 months and it could be later for infants
with a family history of food allergies.
 Consult pediatrician when to give eggs in supplementary feeding.
 Adults with egg allergies must strictly avoids eggs and egg products and foods
containing eggs.

The cheapest source of high quality protein – It has the highest Protein Efficiency Ratio.
FNRI.

It contains all the ESSENTIAL AMINO ACIDS PER – a method for assessing protein quality.

It has CHOLINE for memory function. OVALBUMIN – major protein in egg white.
EGG: PHYSICAL STRUCTURE AND COMPOSITION
1. Yolk
- The lecithin and monoglycerides are responsible for the yolk’s emulsifying
properties.
- It contains more phosphorus, manganese, iron, iodine, copper, and calcium than the
white, and it contains all of the zinc.
- Double-yolked eggs are often produced by young hen whose egg production cycles
are not yet completely synchronized. They are also produced by hens that are old
enough to produce extra large eggs.
- Genetics is also a factor
- A hen will produce double-yolked eggs throughout her egg-laying period.
- With the exception of riboflavin and niacin, the yolk contains higher proportion of
the egg’s vitamins than the white.
- It contains lipids and fat-soluble vitamins A, D and E and is one of the few foods
naturally containing vitamin D.
- The lipids are triglycerides (3 fatty acids and 1 glycerol) with saturated,
monounsaturated and polyunsaturated fatty acids; lecithin and cholesterol.
- 1 egg yolk has about 200 mg cholesterol compared to 50 mg for 1 ounce of red
meat.
YOLK
 The main protein in egg yolk is VITELLIN, a lipoprotein.
 It also contains PHOSVITIN which is high in PHOSPHORUS and has antioxidant
properties and LIVETIN which is high in SULFUR.
 The yellow to orange-yellow portion that makes up about 33% of the liquid weight of
the egg.
 Yolk – from the Indo-European word that means “bird” and the old English for “yellow”

MEMBRANES
OUTER/SHELL MEMRANE The one just under the shell. It sticks to
the shell.
EGG MEMBRANE The inner membrane. It sticks to the
albumen.
 The covering that protects the yolk from
breaking. It is weakest at the germinal
VITELLINE MEMBRANE disc and tends to become more fragile as
the egg ages. The yolk easily breaks when
the egg is no longer fresh.

2. CHALAZA
- It does not interfere with the cooking or beating of egg white and need not to be
removed, although some cooks strain them when making custard.
- The ropey strands of egg white at he both ends of the egg, which anchor the yolk in
place in the center of the thick white.
- THE MORE PROMINENT the chalazae the FRESHER the egg.
3. ALBUMEN/EGG WHITE
- When egg albumen is beaten vigorously, it foams and increases in volume 6 to 8
times.
- Egg foams are essential for making souffles, meringue, puffy omelets, and angel and
sponge cake.
- Egg white contains more than half the egg’s total protein, niacin, riboflavin, chlorine,
magnesium, potassium, sodium and sulfur.
- Albumen is more opalescent (many different colors when seen from different
angles) than truly white.
- The more viscous consistency of thick albumen is due to the HIGHER
CONCENTRATION OF THE PROTEIN – OVOMUCIN
- Ovomucin has a fibrous character and contribute significantly to the gel-like texture
of thick white. It tends to thin out as egg ages.
- It accounts for most of an egg’s liquid weight- about 67%

ANTIMICROBIAL FACTORS OF EGG WHITE

LYSOZYME A germicidal agent
CONALBUMIN has the ability to bind divalent and trivalent
metallic ions such as iron thus depriving
bacteria with such ions.
(VALENCE – the amount of power of an atom
which is determined by the number of
electrons)
AVIDIN It binds BIOTIN, so eating raw egg white is
NOT recommended. This is easily denatured
when cooked
LACTOFERRIN A protein in breast milk that binds iron and
keeps it from supporting the growth of the
infant’s intestinal bacteria.
  The Loss of CO2  ^ in alkalinity, ^ in pH  From near neutral to pH 9.7  ^ in pH
degrades OVOMUCIN  Affects viscosity  Result: thinning out of the albumen.

ALBUMEN/EGGWHITE
Outer Thin White A narrow fluid layer enclosed by the inner
shell membrane
Outer Thick White A gel that forms the center of the albumen.
Inner Thin White A fluid layer located forms the center of the
albumen
Inner Thick White A dense, matted (not shiny) fibrous capsule
of albumen around the vitelline membrane
(clear seal which holds the yolk) of the yolk.

4. AIR CELL
- Free or floating air cell – an air cell that moves freely toward the uppermost point of
the egg as it is rotated.
- Bubbly air cell- one or more separated cell bubbles floating beneath the main air
cell.
- The location of the air cell becomes apparent in a hard cooked egg – it appears as
flat disk at the large end of the egg.
- The BIGGER the AIR CELL, the LOWER the EGG QUALITY.
- Older Eggs have BIGGER AIR CELL because moisture and carbon dioxide leave
through the pores and air enters to replace them.
- In Candling, the size of the air cell is used as one basis for determining egg quality.
- Fresh eggs have air cell that do not exceed 1/8 inch in depth and is about the size of
a 10-centavo coin.
- When an egg is first laid, it is warm. As it cools, the inner shell membrane separates
from the outer shell membrane to form the AIR CELL.
- An empty space between the white and shell at the large end of the egg is barely
existent in newly laid egg.

5. SHELL
- If the diet is deficient in calcium, the hen will produce a thin or soft-shelled egg or no
shell at all.
- Shell thickness is also related to egg size which, in turn, related to the hen’s age. As
the hen ages, egg size increases.
- It is largely composed of calcium carbonate (94%)
- Shell Strength is greatly influenced by the minerals and vitamins in the hen’s diet,
particularly calcium, phosphorus, manganese and Vitamin D.
- It is porous, containing 7 to 17 thousand tiny pores with a greater number at the
large end of the shell.
- As the egg ages, these tiny holes permit moisture and carbon dioxide to move out
and air to move in to form the AIR CELL, a pocket of air at the larger end of the egg.
 - the outer covering that accounts for about 9 to 12% of the total weight depending
on egg size.
- The first line of defense against bacterial contamination and helps reduce moisture
losses.

EGG: INTRODUCTION AND IMPORTANCE

- A convenient food - Favorite for “baon”
- Breakfast menu. - Affordable, nutritious meal/s
- Eateries menu - Street food

EGG: PHYSICAL STRUCTURE AND COMPOSITION

 Shell
- The same amount of shell material which covers a smaller egg must be “stretched”
to cover a large one, hence the shells of bigger eggs are thinner.
- Shell color indicates the breed of the hen but has no bearing on the nutrient content
or taste of the egg.

 Germinal Disc
- The entrance of the LATEBRA, the channel leading to the center of the yolk.
- It is barely noticeably as a slight depression (low) on the surface of the yolk.

 Yolk
- The yolk material serves as a food source for embryonic development.
- it contains all of the fat in the egg and a little less than half of the protein.