Lecture 9 meat preservation techniques

MEAT PRESERVATION TECHNIQUES
Dr. Abdirashid Ahmed Hussein
BSc IN Veterinary science department of animal husbandry in
university of Somalia (Uniso)
BSc in public health in Somvill university
Email: abwaanrashka39@gmail.com
Lecture: 9

MEAT PRESERVATION TECHNIQUES
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 isconsumed.
• Whatever the process, meat preservation is in place to
save those who consume the meat from contracting
food-borne diseases

Why Preserve Meat
1. Delays products spoilage
2. Extends life of the products
3. Improves product quality

Types of Preservation Techniques
1. Freezing
2. Chilling
3.Canning
4.Drying
5.Salting
6.Irradiation
7.Dehydration
8.Smoking

 FREEZING
# Since the time frame of “world war 2” freezing has
become most popular way to preserve meat Temperature:
Ideal temp.(-55ºc)
Commercially(-29ºc)
Domestically(-18ºc)
Works by stopping enzyme activity& microbial growthof
bacteria ,yeast & moulds
Almost 98% of water freezes at -20ºc
Complete crystal formation occurs at -65ºc
Fast freezing produce better quality than low freezing
Microbial growth stops at -12ºc

Disadvantage of freezing
During slow freezing formation of large ice crystal damage
the cell and results in a protein denaturation
Sometimes the texture of meat changed by this process
Duration of frozen meat lasting
Beef -12 months
Lamb- (6-9months)
Poultry-(3-6 months)
Pork-6 months

CHILLING
It is necessary to reduce the temperature of carcass immediately after
evisceration to 4ºc within 4 hours of slaughtering
Two types :
1] Immersion chilling: The product is immersed in chilled(0-4c)water
2] Air chilling: Carcasses are misted with water in a room with chilled air .
Air chilling procedure is safer than water chilling procedure with
respect to microbiological count .
It helps to prevent denaturing of proteins.

CANNING
Canning is the process of applying heat to foods that sealed
in a jar in order to destroy any microorganisms that can
cause food spoilage
• Mainly two types:
•
1) Water bath canning
2)Pressure canning
For meat we generally use pressure canning that produces steam
at 240c temperature During the canning process air is driven from
the jar and a vacuam is formed as the jar cools and seals.

DRYING
Drying may be done for the single purpose of dehydrating fresh meat
for extension of storage
Drying & fermentation must go hand in hand to achieve the desired
flavour and shelf life
Generally two types:
1)Sun drying
2)Solar drying
* Tunnel dryer
*Multi collector dryer
Temperature: 70º-80ºc

Disadvantage of drying
Continuous evaporation and weight losses during drying
causes changes of the shape of meat through shrinkage
Meat pieces become smallest,thinner & darken in color
Texture of meat also changes from soft to firm to hard

IRRADIATION
Irradiation does not make foods radioactive, compromise
nutritional quality, or noticeably change the taste, texture,
or appearance of food. In fact, any changes made by
irradiation are so minimal that it is not easy to tell if a
food has been irradiated.
Food irradiation (the application of ionizing radiation to
food) is a technology that improves the safety and
extends the shelf life of foods by reducing or eliminating
microorganisms and insects. Like pasteurizing milk and
canning fruits and vegetables, irradiation can make food
safer for the consumer. The Food and Drug Administration
(FDA) is responsible for regulating the sources of
radiation that are used to irradiate food

PROCESS OF IRRADIATION
There are three sources of radiation approved for use on foods.
Gamma rays are emitted from radioactive forms of the element
cobalt (Cobalt 60) or of the element cesium (Cesium 137).
Gamma radiation is used routinely to sterilize medical, dental,
and household products and is also used for the radiation
treatment of cancer.
X-rays are produced by reflecting a high-energy stream of
electrons off a target substance (usually one of the heavy
metals) into food. X-rays are also widely used in medicine and
industry to produce images of internal structures.
Electron beam (or e-beam) is similar to X-rays and is a stream of
high-energy electrons propelled from an electron accelerator into
food.

ADVANTAGE OF IRRADIATION
Prevention of Foodborne Illness – to effectively
eliminate organisms that cause foodborne illness, such
as Salmonella and Escherichia coli (E. coli).
Preservation – to destroy or inactivate organisms that
cause spoilage and decomposition and extend the shelf
life of foods.
Control of Insects – to destroy insects in or on tropical
fruits imported into the United States.
Irradiation also decreases the need for other pest-control
practices that may harm the fruit.

SMOKING
Smoking, as a mode of food preservation, is probably as
old as cooking with fire. Heat and smoke infuse a
delicate flavor into fish, ham, poultry and meat and can
prevent the growth of microbes. While smoking done
right is a very effective form of food preservation, care
must be taken to avoid contamination and food-borne
illness.

TYPES OF SMOKING
• Hot Smoking: Hot smoking is done in the smokehouse or more
modern electric kilns, usually over a short period of time, just
until the meat is cooked. The meat is cooked and smoked at
the same time over a burning fire or electric elements of a
kiln.
• Cold Smoking: “Cold Smoking” is done over a much longer
period of time, e.g. 12-24 hours, over a smoldering fire (below
85°F). Since foods are held in the temperature danger zone, rapid
microbial growth (40-140°F) could occur.
• Liquid Smoke: Many consumers and commercial operations
use liquid smoke to add smoke flavor to their foods. Liquid smoke
has advantages over traditional smoking in that it can be more
precisely controlled and the smoke flavor is instantaneous.

Advantages Of Smoking
Kills bacteria and slows growth of other types of
bacteria
Adds some flavor to foods
Prevents fats from developing a terrible taste
 Changes color (makes the food pleasing to the
eye)
Can last longer in shelf life

Disadvantages Of Smoking
Eating too much smoked food can lead to some cancers

Salting or Curing
• salted meat is preserved or cured with
salt.Salting,either with dry salt or brine,was
a common method.
• Salt inhibits the growth of microorganisms by
drawing water out of microbial cells through
osmosis.
• Concentrations of salt up to 20% are required to
kill most species of unwanted bacteria.

Advantage:
 Makes water unavailable for
microbial growth.
 Process does not destroy
nutrients.
Disadvantage
 Produces concentrated form
of food. Inhibits microbial
growth & autolytic
enzymes. Retains most
nutrients.

Dehydration
Dehydration, in food processing, means by which many
types of food can be preserved for indefinite periods by
extracting the moisture, thereby inhibiting the growth of
microorganisms.
Advantage
It’s the most nutritious way to preserve food –
enzymes, vitamins, and minerals aren’t destroyed
by high canning temperatures.
Dehydrating food is a quick and easy way to preserve
food.
Glass, plastic, or metal air-tight food containers can be
used to store your dehydrated fruit, vegetables, and
meat.

Disadvantage
Dehydrated foods have different properties than
fresh ones, and they can be less healthy.
Dehydration is a process that removes water,
dehydrated foods are higher in calories per
ounce than their fresh counterparts.
It can be high-Sugar.

THANK YOU EVERYONE
have any question

Lecture 9 meat preservation techniques

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