Processing of Egg

1. INDUSTRIAL
PROCESSING
OF EGGS
Mrs.R.Sinthiya
Assistant Professor
Department of Food Processing and
Preservation Technology
Faculty of Engineering
Avinashilingam Institute for Home
Science & Higher Education for
Women University, Coimbatore

2. •Egg is a biological structure intended by nature
for the production of a chick.
•Consists of three main parts yolk,
albumen,and shell.
•To handle the problems of preservation
and marketing of eggs a clear cut idea
about the formation and structural
details are necessary.

4. SHELL:
 It forms the protective
covering of inner contents of
the egg along with the two
membranes.
SHELLMEMBRANES:
 Within the shell are inner
and outer membrane –porous
and composed of fibres.

5. EGG WHITE:
 three layers –two areas of thin white encompassing
one area of thick white.
EGG YOLK:
 The yolk is enclosed in a sac called the vitelline
membrane.
 The chalazae appears as small twisted ropes of
thickened white.

6.  Unique combination of nutrients for persons of all ages.
 Rich in protein,low in caloric value-to curb obesity and other health
problems.
 Egg protein-high biological value .
 Used as a standard for measuring the quality of other food protein.
 Eggs are also known for their vitamin content.
 Vitamins A,D,E are mainly concentrated in the yolk protein.
 Eggs are also known for their fatty acids-saturated and unsaturated.

8. FEEDING
EGG PRODUCTION
COLLECTION
STORAGE

9.  Young birds are fed a
high protein diet(20%)during
the first few weeks of life.
 During the laying phase
lysine,methionine,calcium and
phosporous are precisely
monitored to support egg
production.
 After the flock vacates the
layer house the house is
stripped of organic matter
and sanitized before another

10.  Producers begin to photostimulate and
manipulate the diet around 18 weeks
of age in order to support egg production.
 When the flock (group of hens)reaches
50% production producers commonly
decide to molt the flock in order to
achieve a higher level of egg production.

11.  There are two primary
methods of egg collection
 inline facilities
 off line facilities.
 Hens lay eggs on to an
angled wirefloor which
rolls the egg toward the
front of the cage on to
nylonbelt

12. OFF LINE FACILITY:
 Nearly identical to inline facility.
 Excepting that the eggs are transported out of the
house directly in to an egg cooling room.

13. INLINE FACILITY:
 Eggs move directly from thelayer house to the egg
processing facility.
 12-14 hours postlay they are washed,inspected,
and graded for packaging.

14.  It is preferable to place the
eggs in filler flat trays
which can be stacked on openracks.
 Refrigerated holding rooms.
 At higher holding temperature
“sweating” is decreased.
 An increase in the relative
humidity causes mustiness and
offodours.

16. COLLECTION
HANDLING,WASHING
GRADING,CANDLING EGG BREAKERS
EGG PRODUCTS
QUALITY CONTROL TESTS
PASTEURIZATION PRESERVATION OF SHELL EGGS
FREEZING AND EGG LIQUID
COLD STORAGE
DRYING QUALITY CONTROL AND STANDARDISATION
DESUGARING
PACKAGING AND MARKETING

17.  Belt conveyors are used
for collecting and conveying
theeggs.
 Frequent collection of
eggs is an important factor
for maintaining its quality.
 The frequency of collection
of eggs should be atleast
three times a day.

21.  Important step to maintain its quality.
 To minimize the problem of damage.
 Use of clean and cool containers while handling is
profitable.
 Hand trucks or skids can be used to move material in
quantity.

22.  The skids are brought in to
the production room and the
individual flats are put on
the conveyor.
 Individual eggs are grasped
by small suction cups and
placed on to another conveyor.
 Now the eggs are moved by
the conveyor in to the cleaner.

24.  They are rotated as brushes and water jets move
carefully across the eggs.
 A fan then dries the egg.
 The cleaned eggs are graded in a candling booth which
is a dark cubical room.

25.  A penetrating light is
shined on the eggs
inorder to grade them.
 Older egg has thinner albumin.
 Yolk casts a sharp shadow and
immediately indicates an older
egg.
 The egg processor is able to
grade the egg during candling.

27.  A sold for household use or at retailmarkets.
 B used mostly for bakery operations.
 C sent to egg breakers which break the
shell and convert to other egg products.

28.  The grading process actually
includes the weighing
of the eggs as well.
Extra large-64 g
Large -56g
Medium -49g
Small -42g

30.  Once graded eggs can be
diverted to the breaking or
pasteurising plant for
furthur processing.
 Only graded eggs are used in
the production of egg
products.

32. EXTERNAL FACTORS:
 shape,
 texture,
 soundness,
 shellcleanliness,colour.
INTERNAL QUALITY:
Condition of yolk,albumen,air cell.

33. SHAPE,TEXTURE:
 A normal egg is oval in shape with one end large and
the other end narrower.
 Shape index=width/length *100
 Unusual shaped eggs have ridges,rough areas,thin
spots.

34. SOUNDNESS OF SHELL:
 A sound egg is one whose shell is intact and
unbroken.
 An unsound egg may be checked leaking or smashed.
 Checked egg:It is defined as one having a crack in the
shell but its shell membranes are intact and its
content do not leak.

35.  CLEAN:shell free from foreign material.
 SLIGHTLY STAINED:shell free from adhering dirt but
shows presence of slight stains on the surface.
 MODERATELY STAINED:moderate degree of stains.
 DIRTY :has adhering dirt and stains covering more than
¼ th of the total surface area.

36.  Nothing to do with its quality.
 It is not one of the quality parameters.
INTERIOR QUALITY OF EGG
 Candling process give an idea about the thick albumen
condition.
 The size and depth of the aircell increases with ageing.

37.  Preservation of egg shell depends
mainly on the gentle handling ,
proper filling of egg baskets,
using right type of packaging materials
proper transport and stacking of cases.
 Eggs for cold stores should not be
washed they must be nest clean,sound in
condition and of good interior quality.
 Cold stores meant for eggs should not
be used for storing any other products.

38.  Liquid egg products have
become a suitable outlet
for distribution of surplus
eggs in the commercial channel.
 Since liquid eggs act as an
excellent media for the growth
of the pathogens continuous
inspection and regulations are
necessary.
 Freezing causes a drastic
reduction in bacterial number.
 Pasteurisation of eggliquid
has become mandatory.

39. The various preservation methods are
 Pasteurisation
 Freezing
 Cold storage
 Drying

40.  The temperature recommended for
pasteurisation of egg white is
56 to 57 degree celcius with
preheating for a minute at
45 degree celcius followed by
pasteurisation for 3 to 4 minutes.
 Various substances may be added to
stabilize liquid egg against heat denaturation.
 Plate type HTST pasteurizers are
used for pasteurization.
 The use of 60 degree celcius for atleast 3
to5 mins leads to a small reduction in
volume and functional properties.

41.  The pasteurization processes in use are
LACTIC ACID –ALUMINIUM SULPHATE PROCESS:
 60 to 62 degree celcius for 3 to 4 minutes.
 Egg white is cooled.
HEAT PLUS –HYDROGEN PEROXIDE PROCESS:
 50 to 54 degree celcius for 3 to 4 minutes.
 Egg white is cooled.
HEAT PLUS VACUUM PROCESS:
 17-24 vacuum is applied for liquid egg
 Air from the albumin is removed in this process.

42. FREEZING:
 Frozen egg yolks have become viscous and gummy on
thawing unless they are mixed with sugar or salt
syrup before freezing.
 Freezing destabilises the surface of the tiny lipid
protein particles(lipoprotein)in egg yolk.
 The gel structure of the coagulated protein is
damaged by ice crystal formation.

43.  Eggs are usually stored at -15 to 0 degree celcius which
is above their freezing point.
 They remain in desirable condition only if the storage
room is well controlled at humidity 85-90%,circulation of
air,free from objectionable odour.
 Eggs retain the quality as long as six months in the cold
storage.

44.  Satisfactory method for
preserving the eggs either whole or
as separated yolks or whites.
 Spray dried egg white have
longer shelf life.
 To retain the functional
properties dried white require
treatment to remove last traces
of glucose.
 It helps to control maillard
reaction.

45.  When native egg white powder is heated to high
temperatures for a substantial length of time it leads to
darkening due to reaction between glucose and several of
the egg proteins.
 The key to prevent off flavor and off odour is to remove
the glucose from liquid egg prior to drying.

46.  SPONTANEOUS MICROBIAL FERMENTATION:
Evolution of carbondioxide halts at 6th
or 7th
of
fermentation.
 CONTROLLED BACTERIAL FERMENTATION:
It reduces the fermentation time,dried powder is uniform.
 YEAST FERMENTATION:
Little change in acidity.

47. MICRO BIOLOGICAL ANALYSIS:
It is done based on the counts of
 Yeasts
 Salmonella
 Coliforms
 Staphylococcus
 Streptococcus
CHEMICAL ANALYSIS:
Qualities like color,salt,sugar,percent yolk and white are
analysed.

48. SENSORY ANALYSIS:
 Flavor
 Palatibility
standardization is done as per weight,shellquality,
Interior quality of egg.

49.  The packing machine
assembles the cartons
based on the weight
of individual eggs.
 The heaviest eggs are
found and packed in to
the extra large cartons.

50.  Packingmaterial varies but is generally either
recycled cardboard or a colored polystyrene .
 After packing the cartons are placed on a conveyor
and placed in to flats by machine put in to
refrigerated trucks and sent to be sold.

51. REFRIGERATED LIQUID PRODUCTS
WHOLE WHITE YOLKS
FROZEN EGG PRODUCTS
WHITES WHOLE YOLKS(SUGARED)

52. DRIED EGG PRODUCTS
SPRAY DRIED EGGWHITE SOLIDS INSTANT EGG WHITE SOLIDS WHOLE EGG SOLIDS EGG YOLK SOLIDS

53. SPECIALITY PRODUCTS
WHOLE HARD COOKED EGG SUBSTITUTE PRODUCTS SCRAMBLED EGG MIXES

54. AIR IS HEATED IN AIR HEATER
DRYING CHAMBER THROUGH AIRDISPENSOR
EGG PULP IS FED
CENTRIFUGAL ATOMIZER
EXHAUST AIR IS REMOVED
PNEUMATIC CONVEYING SYSTEM
POWDER TO POWDER SEPARATOR
PACKAGING

56.  EGG ALBUMEN POWDERS:
Exhibit very good whipping properties.
Used in bakery /pastry products.
 WHOLE EGG POWDERS:
Spray dried at low temperature.
 EGG YOLK POWDERS:
It can be used as a substitute of fresh egg yolk in
formulations where emulsion,color are important.