21 Methods of preservation of poultry meat

Insha Rafiq Syed

epgp books

 

INTRODUCTION

  • Meat is a highly perishable food.
  • Susceptible to deterioration by microbial growth, chemical change and breakdown by endogenous enzymes.
  • Destroying microbial growth and enzymes using heating procedures (cooking and canning),or removal of water by drying or osmotic control.
  • very recently, ionising Use of chemicals to inhibit growth  radiation.
  • Traditionally drying in wind and sun, salting and smoking to preserve it.

 

How to preserve meat

 

Deep freeze

  • easiest way to preserve meat for the short term is freezing.
  • meat wrapped tightly in foil or in plastic package.

 

Salt

  • used as a means of preserving meat.
  • either rubbed on meat or meat is dipped in brine.

 

Pickle the meat

  • using vinegar and spices
  • vinegar keeps parasites and bacteria away for up to six months
  • spices add taste to meat.

 

Jerky

  • popular method of preserving meat
  • drying out the meat

 

Meat preservation:

  • highly perishable due to nearly neutral pH (low acid food)
  • high moisture  and rich nutrients.
  • good source for  microbial growth
  • various undesirable biochemical reactions leading to its deterioration.
  • different procedures employed to stop the undesirable conditions

 

Various preservation  methods:

 

1. Chilling /Refrigeration

 

2. Freezing

 

3. Curing

 

4. Smoking

 

5. Canning

 

6. Dehydration

 

7. Irradiation

 

Chilling/Refrigeration

  • widely used method for short term storage
  • slows down the microbial growth and enzymatic as well as chemical reactions.
  • technique of preservation applied from ancient times
  • meat was stored in natural caves where temperatures were relatively low throughout the year.
  • Chilling  reduces surface temperature
  • enhance carcass drying resulting in reduction of microbial growth. ØCritical process in terms of meat hygiene, safety, shelf life,appearance and eating quality.
  • temperature for chilling process ranges from1°C to 4°C.
  • slaughtering and meat cutting carried out under strict hygienic conditions.
  • refrigeration begins with chilling of animal carcasses continues through the entire  process of  holding, cutting, transit, retail display and even in the consumer household before ultimate use.
  • relative humidity  generally kept 90%
  • carcasses first held in chill coolers (15°C) to remove their body heat
  • passed on to holding coolers (5°C).
  • Poultry with high microbial load.
  • Care taken during handling to check further microbial contamination.
  • Refrigerated temperatures favor the growth of psychrophilic organisms
  • Causing spoilage of meat occurs in due course of time.
  • fresh meat maintains good condition for a period of 5-7 days at a refrigerated temperature of 4±1°C.
  • Processed  meat  products  are       stored  under  refrigeration  have long shelf life as compared to their raw ones.
  • Processed products less perishable and life of poultry meat is 3-6 months under refrigerated conditions.

 

Freezing

  • best and most simple option for preserving poultry.
  • process for long term preservation of meat.
  • stops the microbial growth and retards the action of enzymes
  • retains most of the nutritive value of meat during storage
  • little loss of nutrients occur in the drip during thawing process
  • Meat wrapped in suitable packaging films before freezing to prevent it from under going freeze burn.
  • slow freezing freezes the outer water more quickly as compared to inner water resulting  in  formation  of  larger  ice  crystals  damaging  the  muscle tissue.
  • fast freezing,  forms various small ice crystals uniformly throughout the tissue.
  • drip loss during thawing is low in fast freezing
  • small ice crystals also impart it a desired lighter colour as compared to slow frozen meat.

 

 Types of freezers:

  Different  freezers are used such as;

  • Plate type freezers with  temperature -10°c.
  • Blast type freezers with temperature from -10 to -30°C.

 

Curing:

  • It is a heavy salting age old practice.
  • widely used method of preserving meat before the days of refrigeration.
  • done for imparting specific flavor and colour development, in addition to preservative effect.
  • main ingredients include sodium chloride, sodium nitrite, sodium nitrate and sugar.

 

Properties of ingredients:

Sodium chloride /common salt;

  • inhibits the growth of spoilage bacteria by dehydration and alteration of osmotic pressure
  • slows down the action of enzymes.
  • reacts with fatty acids to enhance the flavor of the cured products.
  • contributes to the tenderness of the product.

 

Sodium nitrates and nitrite;

  • responsible for imparting the attractive cured meat colour and characteristic cured meat flavor.
  • Nitrates and nitrites permitted levels ;500 ppm and 200 ppm respectively
  • inhibit the growth of a number of bacteria especially Clostridium botulinum.
  • also retard the development of rancidity.

 

Sugar;

  • suppresses the harsh hardening effect of salt  adds to the flavour development
  • also serves as an energy source for nitrate reducing bacteria in the curing solution.
  • Mainly sucrose or dextrose used for this purpose

 

Smoking:

  • known to man as a preservation for a long time.
  • meat is subjected to smoke house, where saw dust or hardwood are subjected to combustion at a temperature of about 300°C. ØHigh temperature desirable to minimize the production of carcinogenic compounds.
  • Smoke generation accompanied by formation of numerous organic compounds (aldehydes, ketones, organic aicds, phenols etc) and their condensation products.
  • Aldehydes and phenols condense to form resins contribute most of the colour of smoked meat products.
  • Phenols act as bacteriostatic formal- dehyde as bactericidal compound besides imparting characteristic smoky flavor.
  • Preservation also due to surface dehydration, lowering of surface pH and antioxidant property of smoke constituents.
  • Curing and smoking of meat are interrelated

 

Canning:

  • applying heat to sealed food container in order to destroy microorganisms  thermal sterilization of a product held in hermetically sealed containers is achieved.
  • preserves the sensory attributes such as appearance, flavor and texture to a large extent.
  • have a shelf life of atleast 2 years at ambient temperature.

 

Canning process is performed as;

 

• Lean and clean meat taken and mixed with gravy

• prepared using condiments, tomatoes, dry spices,and  salt in water

• cooked for some time so that all the ingredients get properly mixed in the water.

• mixture  then precooked at 70°C for 15 minutes.

• filled in cans by leaving proper headspace.

• exhausted to remove the air from the container.

• seaming is done and then retorting or thermal processing to achieve sterility.

• At last cooling performed followed by storage at cool and dry place.

 

Dehydration:

  • oldest known method of preserving food  dried and exposed to a temperature high enough to remove the moisture.
  • process of removal of water from meat nutrients making them unavailable to the microorganisms.
  • lowers the water activity considerably prevent the growth of spoilage organisms.
  • Different drying procedures are employed such as mechanical drying, freeze drying, etc.
  • Mechanical involves the passage of hot air with controlled humidity.
  • Freeze drying satisfactory process ,due to better reconstitution properties, nutritive quality and acceptability.
  • Freeze drying involves removal of water from a food by sublimation keeping it under vacuum and giving a low heat treatment.
  • Meat is first frozen at -40 °C.
  • Then dried under vacuum for 9-12 hours at low temperature in plate heat exchangers at 1 to 1.5 mm pressure of mercury.
  • Ice crystals get sublimated to water vapour no rise of temperature.

 

Irradiation:

  • Radiation is the emission and propagation of energy in the material medium.
  • works by exposing meat to radiant energ destroys most but not all microorganisms.
  • can destroy the microorganisms by fragmenting their DNA molecules causing ionization of inherent water within microorganisms.
  • microbial destruction takes place without significantly raising the temperature of food.
  • Irradiation referred as cold sterilization.
  • Among radiations, alpha and beta-rays are used Gamma radiations produce desired effect only during food irradiation.
  • dose of 50-100K rad enhance the shelf-life of fresh meat cuts and poultry products by 19 days dose of 4-5 Mrad  can sterilize pork, poultry and fish.
  • ultraviolet radiations of 2650A° are most bactericidal in nature, dose of 2 – 5 kGy extend the shelf life of poultry stored at 1-3°C by 8-14 days.
you can view video on Methods of preservation of meat

 

Refrences

  • Barbut, S. and C. J. Findlay. (1989). Sodium reduction in poultry products: a review. CRC Critical Rev. in Poultry Biol. 2:59.
  • Barat, J. M., Grau, R., Ibanez, J. B., Pagan, M. J., Flores, M., Toldra, F., et al. (2006). Accelerated processing of dry-cured ham. Part I. Viability of the use of brine thawing/salting operation. Meat Science, 72(4), 757–765.
  • Hotchkiss, J. H., R. C. Baker and R. A. Qureshi. (1985). Elevated carbon dioxide atmospheres for packaging poultry. II. Effects of chicken quarters and bulk packaging. Poultry Sci. 64:333.
  • Josephson, E. S. (1983). Radapperization of meat, poultry, NAMP. (1999). The Poultry Buyer Guide. North Amer.
  • Meat Processors Assoc., Reston, VA.
  • Niemand, J. G., G. A. M. Haauser, I. R. Clark and A. C. Thomas. (1977). Radiation Processing of Poultry. Report PER-16, Atomic Energy Board. Pelindaba, South Africa.
  • Thayer, D. W. (1994). Wholesomeness of irradiated foods. Food Technol. 48(5):132.
  • Yun, J., F. Shahidi, L. J. Rubin and L. L. Diosady. (1987). Oxidative stability and flavour acceptability of nitrite-free curing systems. Can. Inst. Food. Sci. Technol. J. 20:246.