Meat preservation techniques, THERMAL PROCESSING, ADVANCE TECHNIQUES.

Introduction:Canning was first introduced in 1782 by Nicolas Appert
In 1837, Louis Pasteur, utilized heat to eliminate bacteria
Use of sodium benzoate as a preservative in certain foods in 1980
In 1990, irradiation of poultry was approved in the United States
MEAT PRESERVATION
CHILLING OR REFRIGERATION
Done at a temperature of 2 to 5°C for fresh meat
Refrigeration of carcass in coolers (15°C) before being hung
Moved on to holding coolers to eliminate their body heat (5°C)
COMMON METHOD OF REFRIGERATION

FREEZING
Preserve fresh meat's unique properties
Meat contains 50-75 percent water by weight
Reduces the microbial load and slows enzyme activity.
Preserve majority of the nutrients
To freeze fresh meat, wrap it in a suitable packaging film first
The freezing rate has an impact on the quality of frozen meat
Slow freezing results in the production of big ice crystals
During rapid freezing, a large number of tiny ice crystals form
At -20°C, complete crystal formation occurs
At -65°C, entire crystal formation occurs.
At -12°C, microbial growth ceases
Below -18°C, inhibition of metabolism occurs in mammalian tissues
Approximately 60% of the water is frozen during the freezing process
CURING
Curing is a food preservation method in which meat, fish and vegetables are processed by addition of salt to remove the moisture by osmosis.

Curing ingredients:
Sodium chloride
Sodium nitrite
Sodium nitrate
Sugar

SODIUM CHLORIDE
It is a common salt.
It is old practiced Method
Today, common Salt and sodium nitrate
Inhibit microbial growth by drawning moisture out of food that decrease water activity.
20% NaCl used to Inhibit food spoilage yeast.
Genera bacillus and micrococcus tolerant to High salt concertation.

SUGAR
Sugar is a humectant bind with moisture and reduce water activity.
Dextrose, sucrose, brown sugar, lactose, honey, molasses and starches are used as curing agents.
Enhance flavor by producing browsing effect.
Reduce harshness of salt
In Canada, they are GRAS.

CURING METHODS
Dry cure
Pickle cure
Injection Cure
direct cure

Dry cure
In dry cure, entire meat pieces is hand sprinkled with salt then dried or smoked for desired flavor.
Brine curing is done by mixing water and a curing agents.
Brine cure takes 4days to complete while dry cure is faster method.
Injection cure
Most of the meat we loved goes under various methods of preservation and tenderization.
Injection curing is industrial applied method where a solution of salt along with other seasonings mixed are formed as brine. This brine is then injection in meat to obtain desired flavor.
Picked meat
Picked meat is also an old practice. A pickling solution is formed that include curing with sodium nitrate, nitrite, sodium chloride, salt and sometimes vinegar.

PASTEURIZATION
It is moderate heating method
Pasteurisation process is applied when product is subjected to refrigeration.
A temperature of 58-75°C is used.
It extend shelf life of meat.

1. PRESERVATIVE TECHNIQUES FOR MEAT

2. Introduction: Canning was first introduced in 1782 by Nicolas Appert In 1837, Louis Pasteur, utilized heat to eliminate bacteria Use of sodium benzoate as a preservative in certain foods in 1980 In 1990, irradiation of poultry was approved in the United States

3. MEAT PRESERVATION To prevent foodborne illness and intoxication To ensure that food is free of microorganisms To keep food from spoiling To increase the food's shelf life To improve the food preservation quality To minimize monetary losses FOOD PRESERVATION SERVES FOLLOWING PURPOSES:

4. CHILLING OR REFRIGERATION Done at a temperature of 2 to 5°C for fresh meat Refrigeration of carcass in coolers (15°C) before being hung Moved on to holding coolers to eliminate their body heat (5°C)

5. IMMERSION CHILLING involves immersing the product in a cooled (4°C) environment WATER CHILLING the corpses are misted with water AIR CHILLING controlled flows of chilled air to bring the product to the desired temperature COMMON METHOD OF REFRIGERATION

6. Preserve fresh meat's unique properties Meat contains 50-75 percent water by weight Reduces the microbial load and slows enzyme activity. Preserve majority of the nutrients To freeze fresh meat, wrap it in a suitable packaging film first The freezing rate has an impact on the quality of frozen meat FREEZING

7. Slow freezing results in the production of big ice crystals During rapid freezing, a large number of tiny ice crystals form At -20°C, complete crystal formation occurs At -65°C , entire crystal formation occurs. At -12°C, microbial growth ceases Below -18°C, inhibition of metabolism occurs in mammalian tissues Approximately 60% of the water is frozen during the freezing process

8. CURING Curing is a food preservation method in which meat, fish and vegetables are processed by addition of salt to remove the moisture by osmosis. Curing ingredients: Sodium chloride Sodium nitrite Sodium nitrate Sugar

9. SODIUM CHLORIDE SODIUM NITRITE It is a common salt. It is old practiced Method Today, common Salt and sodium nitrate Inhibit microbial growth by drawning moisture out of food that decrease water activity. 20% NaCl used to Inhibit food spoilage yeast. Genera bacillus and micrococcus tolerant to High salt concertration. Used as salt in meat preservation industry. Gives Stable red color More Cured flavour It controls lipid oxidation to retard rancidity Controls anaerobic bacteria Limit used- 156ppm in US, 200ppm in Canada. Form Carcinogenic nitrosamines when used as food additive but has no evidence in relation with cancer.

10. NITRATE SUGAR Not commonly used as curing agent because it is difficult to remove. Eliminate bacteria at low temperature 2-4°c Sugar is a humectant bind with moisture and reduce water activity. Dextrose , sucrose, brown sugar, lactose, honey, molasses and starches are used as curing agents. Enhance flavor by producing browsing effect. Reduce harshness of salt In Canada, they are GRAS.

11. CURING METHODS Dry cure Pickle cure Injection Cure direct cure

12. Dry cure In dry cure, entire meat pieces is hand sprinkled with salt then dried or smoked for desired flavor. Brine curing is done by mixing water and a curing agents. Brine cure takes 4days to complete while dry cure is faster method. Injection cure Most of the meat we loved goes under various methods of preservation and tenderization. Injection curing is industrial applied method where a solution of salt along with other seasonings mixed are formed as brine. This brine is then injection in meat to obtain desired flavor. Picked meat Picked meat is also an old practice. A pickling solution is formed that include curing with sodium nitrate, nitrite, sodium chloride, salt and sometimes vinegar.

13. SMOKING Aid long term preservation in meat. Smoked flavor is highly liked by customers. Special smoke is produced by wood degradation from combustion of hard wood, sawdust, maple and damp wood chips at a temperature of 300°C to obtain desired flavor. Smoking causes surface dehydration by sealing outer layer of meat and make it difficult for bacteria to enter. Smoking styles Different style of smoking is performed like hot smoking, cold smoking, smoke roasting like barbecue and liquid smoking. Liquid smoke is produced by combustion of hard wood that removes aromatic polycyclic hardocarbons by filtration. Smoke form organic compounds with their condensation product like aldehyde and phenols . Liquid smoke impart smoky flavor.

14. THERMAL PROCESSING Kill spoilage microorganisms Methods: Pasteurization Sterilization

15. PASTEURIZATION It is moderate heating method Pasteurisation process is applied when product is subjected to refrigeration. A temperature of 58-75°C is used. It extend shelf life of meat. STERILIZATION It is severe heating method. A temperature of above 100°C is used. It is used to kills all spoilage microbes but some resistant spores still remains alive. In canned foods, when higher sterilization temperature is applied sulfhydryl favors are produced that modifies the texture of meat.

16. CANNING It is the process of preservation achieved by thermal sterilization of a product held in hermetically sealed containers. Canning retains the sensory attributes of meat products such as appearance, flavor, and texture to a considerable extent.  Furthermore, canned beef products have a two-year shelf life at room temperature.  Meat, wild game, poultry, and fish are low-acid foods that must be processed in a pressure canner for the full time recommended to kill food-poisoning bacteria like C. botulinum spores. 

17. STEPS OF CANNING

18. DEHYDRATION  When water is removed from beef concentrate, water soluble nutrients are rendered unavailable to microorganisms. Water activity measures the amount of water that is unavailable to microbial cells. Dehydration reduces water activity, which inhibits the growth of spoilage-causing microorganisms.  SUN DRYING: Mean of preservation in ancient days MECHANICAL DRYING: The mechanical drying procedure comprises the passage of heated air with a controlled humidity.

19. FREEZE DRYING  Removal of water from a food by sublimation from the frozen state to vapor state by keeping it under vacuum and giving a low heat treatment   Widely used for preparation of dehydrate meat soup mixtures Freeze drying of meat is a satisfactory process of dehydration, preservation due to better reconstitution properties, nutritive quality and acceptability of the meat products.  Steps:  Pre-freezing  Primary drying  Secondary drying

20. STEPS: Meat is first frozen at -40°C, then dried in plate heat exchangers under vacuum for 9-12 hours at low temperature at 1-1.5 mm Hg pressure. There is no temperature rise because ice crystals are sublimated into water vapor.  The first phase of drying removes free and immobilized water from the meat, which is freezable and accounts for 90-95 percent of total moisture.  To eliminate the remaining 4-8 percent bound water, a further drying process is carried out at a high temperature.  Freeze-dried foods are vacuum-packed and have excellent storage stability.

21. IRRADIATION Irradiation is also known as “cold sterilization”. It is the emission and propagation of energy in the material media.  Electromagnetic radiations are in the form of continuous waves. They are capable of ionizing molecules in their path.  These radiations can destroy the microorganisms by fragmenting their DNA molecules and causing ionization of water within microorganisms. It is pertinent to mention that microbial destruction of foods take place without significantly rising the temperature of the food Types of radiations Gamma rays (from cobalt-60) Electron beams  X-rays Ultraviolet radiations (bactericidal)

22. CHEMICALS Freeze storage cannot prevent oxidative spoilage and microbial/enzymatic spoilage Combination of refrigeration and chemicals optimize stability and product quality, maintain freshness and nutritional value Should not be used to cover up an already spoiled product

23. Common antimicrobial Organic acids Chlorides Nitrites Sulfides organic acids Benzoic acid Citric acid Propionic acid Sorbic acid Acetic acid Lactic acid Ascorbic acid (vitamin C) Sodium ascorbate D- isoascorbate (erythorbate) COMMON PRESERVATIVES

24. ACETIC ACID Prevent bacterial growth by rupturing bacterial cell wall SORBATE Prevent growth of yeast, inhibit spore formation BENZOIC ACID Anti bacterial activity, inhibit enzymes NITRATES Anti bacterial, inhibit enzyme and fresh appearance ASCORBIC ACID Meat preservative DIFFERENT ACIDS AND THEIR ROLE

25. HYDROSTATIC PRESSURE PROCESSING Non-thermal technology The product submerged into the tank and high pressure is applied over the product uniformly This technique is able to inactivate bacteria, enzymes, mold and bacteria This also preserves the taste, color and nutrient value of food, unlike thermal treatments .

26. Pascals principle Also called i sostatic rule incompressible fluid is used inside un-deformable container Pressure distributes uniformly Pressure is transmitted to each point regardless of composition, size and shape. Le Chateliers principle the pressure accelerates some changes in meat (phase change, changes in the molecular configuration, chemical reactions) inhibits the reaction in meat which takes place due to volume increase PRINCIPLE OF HYDROSTATIC PROCESS

27. - Type of microbe -Pressure level -Temperature -Time of process -Composition of food Pressure range used is 100–600 MPa  at commercial level Change of the texture and appearance and color in the raw meat, depends on the pressure intensity In salted chicken meat, texture of cooked meat and color of raw meat is improved Factors effecting microbes inactivation :

28. HYDRODYANAMIC PRESSURE PROCESSING: High pressure and high energy shock waves through water on meat product is known as hydrodynamic pressure processing Force acting on the solid body which is immersed under water due to the motion of that fluid Its effects are not apparent but show on cooking

29. MECHANISM OF HYDRODYNAMIC PRESSURE : High energy explosions are done under the vessel which generate shock waves whose pressure exceeds the speed of sound. In the time of milliseconds, 70MPa to 100MPa of shock wave occurs. In addition to tenderness, shelf life of meat is also enhanced as microbial growth and production is affected. Meat treated with hydrodynamic pressure processing have microbial growth under control if suitable temperature given for specific time period.

30. CONCLUSION Microbial spoilage results in a sour taste, off-flavors , discoloration, gas production, pH change, slime formation, structural components degradation, ٴ odors and change in appearance. Preservation ensures that the quality, nutritive value and edibility of meat remain intact. It may be noted that modern meat food processors do not rely on any single preservative technique. For controlling enzymatic, oxidative and microbial spoilage, low temperature storage and chemical techniques are the most common in the industry today.