CONTAMINATION, SPOILAGE AND PRESERVATION OF EGG AND MEAT PRODUCT

1. CONTAMINATION, SPOILAGE AND
PRESERVATION OF EGG AND MEAT
PRODUCT
SUBMITTED BY
M DEEPAK KANNAN
BP211521
DEPARTMENT OF MICROBIOLOGY
SACRED HEART COLLEGE (AUTONOMOU
TIRUPATTUR

2. INTRODUCTION
 Meat and its product are highly nutritious food that is widely
consumed by people all over the world.
 Meat can be obtained from various birds (chicken, turkey, ducks, etc.)
or mammals (pork, mutton, buffalo, sheep), and after slaughtering,
carcasses and primary cuts are processed to raw or processed food
products.
 It is a nutritious, protein-rich food that is highly perishable and has a
short shelf life.

3.  The biological and chemical nature of meat leads to its deterioration
from the time of slaughter until consumption.
 Meat and its products such as ham, sausages, cooked meat, dry
meats, smoked meats, vacuum-packed meat, minced meat, etc. are all
susceptible to microbial spoilage.
EGG
 The contents of shell eggs are typically sterile, notwithstanding the
possibility of vertical contamination.
 Nonetheless, contamination happens routinely during the processing
of egg products due to the contact of the eggshells with the egg
content during the egg breakage step.

4.  The microbiological contamination may cause sanitation and/or
spoiling issues. Salmonella enteritidis, one of the most important
organisms involved in outbreaks involving shell eggs and egg
products, is the primary hygienic concern.
 Even though egg safety is still a major problem, the sanitary risk
has been significantly reduced due to the enhancement of hygienic
measures in the breeding environment, the pasteurisation of egg
products, and the observance of the cold chain for their storage.

5.  Nevertheless, microbial deterioration of eggs and egg products can
still result in substantial economic losses.
 In order to meet the ever-changing consumer demand for natural,
safe, nutritious, and delicious foods, preventing egg product spoiling is
a significant concern.

6. CONTAMINATION OF MEAT AND EGG PRODUCT
 Meat spoilage can be caused by natural processes, such as lipid
oxidation or autolytic enzymatic that occurs in the muscle after
slaughtering.
 Several factors are responsible for microbial contamination of meat
such as:
1. Bacterial flora of animal.
2. Knives, utensils, hands, and clothing of the workers.
3. Pre-slaughter handling of livestock and post-slaughter handling of
meat.

7. 4. Handling during slaughtering, evisceration, and processing.
5. Temperature controls during slaughtering,
6. Processing and distribution
7. Type of packaging used
8. Handling and storage
A series of the event takes place during rigor mortis after the slaughter of
the animal such as:
1. Respiration ceases, which stops ATP synthesis.
2. The lack of ATP causes stiffening of muscle

8. 3. Reduction of oxidation-reduction potential due to lack of oxygen
4. The loss of vitamins and antioxidants causes the development of
rancidity.
5. Glycolysis begins in which most glycogen is converted to lactic acid that
reduces pH
6. The ending of a reticuloendothelial system leads to the susceptibility of
meat to microorganisms.

9. 7. Nervous and hormonal regulations cease, thereby causing the
temperature of the animal to fall and fat to solidify.
8. Various metabolites accumulate that also aid protein denaturation.
EGG
 The majority of newly deposited eggs are sterile, at least on the
inside, but the shells quickly become contaminated by faeces from
the hen, the cage or nest, wash water if the eggs are washed,
handling, and sometimes the packaging material.
 According to reports, the total number of microorganisms per hen’s
egg shell ranges from 102 to 107, with a mean of approximately
105.

10.  Diverse species of bacteria were extracted from the shell. Comparing
the flora of the shell and the flora recovered from ruined eggs reveals
that the former has a high number of gram-positive organisms, while
the latter contains a low amount.
 Therefore, the amount of organisms that usually ruin or “rot” the egg
is initially quite modest on the shell. Salmonella spp. may be present
on the shell or within the egg at the time of laying, increase during
processing, and be present in substantial numbers in frozen or dried
eggs.

11. SOURCES OF CONTAMINATION
 By the fecal matters of the chicken
 By Specks of dirt or materials used for the cage or nest
 Water used during washing of eggs
 Equipment used during processing and handling
 Materials used to pack the eggs
 The temperature used during storage
 Presence of eggshell cracks or micro-cracks

12. SPOILAGE OF MEAT AND EGG PRODUCT
 Fresh meat is subjected to spoilage by its enzymes and microbial action.
 The autolysis changes cause proteolytic action on muscle and
connective tissue and hydrolysis of fats.
 The survival and growth of microorganisms are influenced by the
composition of the atmosphere surrounding the meat.
 Fresh meat contains nutrients such as sugars, amino acids, vitamins,
cofactors, etc and it had pH (5.5-5.9) and Aw (0.85) values that
influence the growth of microorganisms.

13.  The most common bacteria isolated from fresh meat are bacteria of the
genera Acinetobacter, Pseudomonas, Brochothrix thermosphacta,
Flavobacterium, Psychrobacter, Moraxella, Staphylococci, Micrococci,
lactic acid bacteria (LAB), and various genera of the
Enterobacteriaceae.
 The microbial pathogens found in fresh meat are Salmonella,
Campylobacter, E.coli, Listeria monocytogenes.
1. Spoilage under aerobic condition
2. Spoilage under anaerobic condition

14. CONDITION KIND OF DEFECTS MICROORGANISMS
Aerobic condition Surface slime Pseudomonas, Moraxella,
Streptococcus, Bacillus,
micrococcus
Aerobic condition The red color of meat called
“bloom” caused by the production
of an oxidizing compound
Lactobacillus, Leuconostoc
Aerobic condition Oxidative rancidity Pseudomanas spp, Archro
mobacter
Aerobic condition Red spot Serratia marcescens
Aerobic condition Blue color Pseudomonas syncyanea
Aerobic condition Greenish blue or brownish black
spot
Chromobacterium lividum
Aerobic condition Stickiness, whiskers, Green
patches
Mold

15. CONDITION KIND OF DEFECTS MICROORGANISMS
Anaerobic condition Putrefaction Clostridium spp,
Alcaligennes, Proteus
Anaerobic condition Souring Lactic acid bacteria

16. EGG
NON – MICROBIAL SPOILAGE OF EGGS
 These include moisture loss and, thus, weight loss during long-term
storage.
 During long-term preservation, egg contents also undergo physical
changes.
 They include egg white thinning and the rupture of the yolk membrane.
 As the membrane of the yolk weakens and breaks, the yolk becomes flat
and uniformly mixed with the egg white.

17. MICROBIAL SPOILAGE OF EGGS
 Microorganisms must infect the shell, penetrate the shell’s pores
and inner membrane, reach the egg white and yolk, and develop
there in order to cause shell deterioration.
 Certain germs are unable to develop in egg white, yet they multiply
fast in egg yolk.
 Changes in storage temperature enhance organism penetration
through shell, hence promoting microbial deterioration.

18. CONTAMINATION OF MEAT AND EGG PRODUCT
 The purpose of meat preservation is to add to the length of time that
meat is fresh, healthy, and bacteria free for human consumption. Meat
is preserved using many different processes.
 The process a specific meat is preserved under is largely determined by
what the meat will be used for when it is consumed.
 Whatever the process, meat preservation is in place to save those who
consume the meat from contracting food-borne diseases

19. Why Preserve Meat?
1. Delays products spoilage
2. Extends life of the products
3. Improves product quality
TYPES OF PRESERVATION TECHINQUES
1. Freezing
2. Chilling
3. Canning
4. Drying
5. Salting
6. Irradiation
7. Dehydration
8. Smoking

20. PRESERVATION OF EGGS
1. Asepsis
 Care is taken to minimise the contamination of the exterior of the shell
by hen faeces and nest dirt.
 When eggs are broken for drying or freezing, care is taken to discard
any that have undergone microbial growth and to reduce
contamination by cleaning and sanitising the equipment.

21. REMOVAL OF MICROORGISMS
 Experiments indicate that hand-washed eggs are more susceptible to rotting
than unwashed eggs, and that machine-washed eggs are more susceptible to
rotting than hand-washed eggs.
 The quantity of decay depends on the type of washing machine and the type
of washing solution.
 Attempts to reduce contamination with rot bacteria by cleaning the
machines and disinfecting with a 1% hypochlorite solution have not always
been successful, but the use of this disinfectant solution as the wash water
has decreased the proportion of rots in the washed eggs.
 The use of 1% to 3% acetic acid was effective in eliminating flora, but
resulted in a decrease in egg quality and shell thickness.

22. USES OF HAET
 By heating at 60 degrees Celsius for 320 seconds, for instance, the rotting
was effectively controlled. Heating with water was more effective than
heating with oil.
 Heating shell eggs in oil for 10 minutes at 60 degrees Celsius or in water for
30 minutes at 54.4 degrees Celsius; heating egg contents at 61.7 degrees
Celsius for 30 minutes; immersion of shell eggs in boiling water for a few
seconds or in hot oil (57.2 degrees Celsius) with or without a vacuum; and
immersion of eggs in a hot detergent-sanitizer solution (43.3 to 54.4
degrees Celsius) are all suggested treatments (the sanitizer being a
quaternary ammonium compound).

23.  A method of thermostabilization that involves dunking eggs in hot water
minimises evaporation of moisture from the egg by coagulating the
outermost portion of the egg albumen. The following are the heat
treatments used in the United States to eliminate salmonellae:
 Whole egg liquid, 60 degrees Celsius for at least 3.5 minutes.
 Plain yolk liquid, 61.1 degrees Celsius for at least 3.5 minutes or 60
degrees Celsius for at least 6.2 minutes.
 Yolk with carbohydrate, 63.3 degrees Celsius for at least 3.5 minutes
or 62.2 degrees Celsius for at least 6.2 minutes.
 Yolk with salt, 63.3 degrees Celsius for at least 3.5 minutes or 62.2
degrees Celsius for at least 6.2 minutes.