Spoilage of Egg and Poultry

2. WELCOME

3. CONTENTS
● INTRODUCTION
● CONTAMINATION
OF EGG
● CHANGES NOT CAUSED
BY MICROORGANISMS
● CHANGES NOT CAUSED
BY MICROORGANIMS
● PRESERVATION OG EGG

4. INTRODUCTION
● Microbial and nonmicrobial spoilage occur in eggs during storage. Untreated
eggs lose moisture and weight during storage. The changes appear with
breathing out the eggs. The white of the egg becomes thinner and more
watery as the egg ages and the yolk membrane becomes weaker.
● The most predominate spoilage (rot) of shell eggs is caused by Gram-
negative motile rods: Pseudomonas, Proteus, Alcaligenes, Aeromonas, and
coliforms. Pasteurized egg products at refrigerated temperatures have
limited shelf life, unless additional preservatives are used.

5. CONTAMINATION OF EGG
● Most freshly laid eggs are sterile, at least inside, but the
shells soon become contami- nated by fecal matter from
the hen, by the cage or nest, by wash water if the eggs
are washed, by handling, and perhaps by the material in
which the eggs are packed.

6. INCIDENCE OF MICROORANISMS ON SHELL OF THE EGG

7. SPOLAGE OF EGG
● Some of the defects of eggs are obvious from
their general appearance, others are shown by
candling with transmitted light, and some show
up only in the broken egg.
Defects in the Fresh Egg
● Fresh eggs may exhibit cracks, leaks, loss of
bloom or gloss, or stained or dirty spots on
the exterior as well as "meat spots" (blood
clots), general bloodiness, or translu- cent
spots in the yolk when candled. From among
these, any breaks in the shell or dirt on the
egg will favor spoilage on storage.

8. Changes During Storage
● The changes that take place in eggs while they
are being held or stored may be divided into
those due to nonmicrobial causes and those
resulting from the growth of microorganisms.
CHANGES NOT CAUSED BY
MICROORGANISMSCHANGES
● Untreated eggs lose moisture during storage and
hence lose weight.
● The amount of shrinkage is shown to the candler
by the size of the air space or air cell at the
blunt endof the egg, a large cell indicating much
shrinkage.
● Of more importance is the change in the physical
state of the contents of the egg, as shown by
candling or by breaking out the egg.

9. The white of the egg becomes thinner and more watery as the egg ages,and
the yolk membrane becomes weaker. The poorer the egg, the more
movementthere is of the yolk and the nearer it approaches the shell when the
egg is twirled during candling. When an old egg is broken onto a flat dish, the
thinness of the white is more evident and the weakness of the yolk membrane
permits the yolk to flatten
out or even break.
CHANGES CAUSED BY THE MICROORGANISMS
Take to be accomplished by causal organisms to Cause Spoilage
● Contaminate the shell
● Penetrate the pores of the shell to membranes shell must be moist)
● Grow through shell membrane to reach white.
● Grow ine ggs white to reach egg yolk.
● Time taken to penetrate varies with organism and temperature
● In general more spoilage is caused by bacteria than by molds.

10. ● Bacteria need to overcome the anti-
bacterial properties of albumen to cause
Spoilage of eggs
● Also thy use the protein complexes as a
Source of nitrogen for Growth.
● Bacterial spoilage Chief is called as rots.
Three chief one are Green
rots,Colourless rots and Black rots.
● The othe Two are Pink rots and red
rots.
Bacteria spoilage of Egg

11. GREEN ROTS
Green rot
● It is caused by Pseudomonas
fluorescence.
● Green egg white shows fluorescence when
exposed to UV light
● In later stage of spoilage, egg yolk
disintegrates and mask green color of
egg white.
● Odor is lacking or fruity or sweetish.

12. COLOURLESS ROTS
● It may be caused by Pseudomonas, Acetobacter, Acinatobacter and
coliform.
● It is caused by Proteus and sometimes Pseudomonas and aeromonas
● Egg yolk blackens and then breakdown to give whole egg content muddy
brown
● Odor is putrified due to H2S
BLACK ROTS

13. PINK ROTS
4. Pink rot
● It is caused by Pseudomonas usually at the
later stage of green rot.
● They are similar to colorless rot except
that pink coloration occurs in yolk and
white.

14. 5. Red rot
● Most infrequently occurring one.
● Caused by a species of serratia.
● Odour is mild & not offensive.
RED ROTS

15. FUNGAL SPOILAGE OF EGG
● Molds causing spoilage of egg includes
Penicillium, Sporotrichum, Mucor,
Botrytis, Alternaria, Thamnidium etc.
● Spoilage of eggs by fungi goes through
stages of mold growth.
● Pin spot molding.
● Fungal rotting.

16. PIN - SPOT MOLDING
● In this case, small compact colonies of mold appear on the shell and
usually just inside the shel
● It is the final stage of spoilage by mold.
● In this case, mycelium of the mold grows through the pores and cracks
in the shell
● Jellying of egg white may occur and colored spots may be produced
● Hypha of mold grows through the yolk membrane and rupture it, so that
yolk mixes with the white.
FUNGAL ROTTING

17. PRESERVATION
● ASEPSIS
● REMOVAL OF MICROORANISMS
● USE OF HEAT
● USE OF LOW TEMPERATURE
● PRESERVATION BY DRYING
● USE IF PRESERVATIVES
● USE OF IRRADIATION

19. CONTENTS