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Liton Chandra Barman Tushar Ahmed Jalal Uddin

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 is consumed. 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 spoilage2. 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 growth of 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

Freezing meat

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 the water chilling procedure with respect to

microbiological count . It helps to prevent denaturing of proteins .

Chillers

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.

canning meat

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. Dried food doesn’t need to be refrigerated.

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