Poultry Products Technology | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Chemical Composition and Nutritional Value of Poultry Meat

• Poultry meat is known for being easy to cook, cost-effective, and rich in essential nutrients.
• Its fibers are tender, easy to chew and digest, with a mild flavor that complements other seasonings.

Table: Chemical Composition of Various Animal and Poultry Products (Raw)

• Water content of different meats:
  • Chicken: 76%
  • Broilers: 12%
  • Turkeys: 1.64%
  • Beef: 57%
  • Hen and Cocks: about 10%
  • Pork: 37%
  • Milk: 87%

Water Content of Edible Portion of Different Classes of Chicken Meat

• Poultry meat comprises water, proteins, lipids, minerals, and vitamins.
• Water Content:
  • Young birds have higher moisture content than older birds.
• Energy Content:
  • Poultry meat is not a significant energy source, making it suitable for specific dietary needs.
  • Different types of poultry meats have varying calorie counts.
• Protein:
  • Poultry meat is rich in protein, with a high biological value and essential amino acids.
  • Cooked poultry meat contains 25-85% protein, depending on the part of the carcass.

Amino Acid Composition

• Poultry meat offers a complete range of essential amino acids crucial for human nutrition.
• Compared to pork and lamb, poultry meat has a higher protein percentage.

Amino Acids Content in Animal Source Foods

Table 4: Amino Acids Content of Various Animal Source Food Items (per cent of the proteins)

• Arginine:
  • Turkey: 6.5%
  • Chicken: 5.7%
  • Beef: 6.7%
  • Pork: 4.3%
  • Milk: 6.4%
• Cystine:
  • Turkey: 1.0%
  • Chicken: 1.8%
  • Beef: 1.3%
  • Pork: 0.9%
  • Milk: 1.0%
• Histidine:
  • Turkey: 3.0%
  • Chicken: 3.6%
  • Beef: 3.6%
  • Pork: 3.6%
  • Milk: 3.6%
• Isoleucine:
  • Turkey: 5.0%
  • Chicken: 6.4%
  • Beef: 6.3%
  • Pork: 4.5%
  • Milk: 6.3%
• Leucine:
  • Turkey: 7.6%
  • Chicken: 8.3%
  • Beef: 8.5%
  • Pork: 8.0%
  • Milk: 7.8%
• Lysine:
  • Turkey: 9.0%
  • Chicken: 9.2%
  • Beef: 9.2%
  • Pork: 8.6%
  • Milk: 9.2%
• Methionine:
  • Turkey: 2.6%
  • Chicken: 2.6%
  • Beef: 2.4%
  • Pork: 2.1%
  • Milk: 2.6%
• Phenylalanine:
  • Turkey: 3.7%
  • Chicken: 4.0%
  • Beef: 4.0%
  • Pork: 3.8%
  • Milk: 4.1%
• Threonine:
  • Turkey: 5.1%
  • Chicken: 5.5%
  • Beef: 5.1%
  • Pork: 5.3%
  • Milk: 5.1%
• Tryptophan:
  • Turkey: 1.5%
  • Chicken: 1.6%
  • Beef: 1.5%
  • Pork: 1.5%
  • Milk: 1.6%
• Tyrosine:
  • Turkey: 2.5%
  • Chicken: 2.5%
  • Beef: 2.7%
  • Pork: 2.7%
  • Milk: 2.5%
• Valine:
  • Turkey: 6.7%
  • Chicken: 7.5%
  • Beef: 6.8%
  • Pork: 6.6%
  • Milk: 7.3%

Understanding Fat Content in Poultry and Red Meats

• Fat Variation in Poultry Meat:
  • Cooked turkey skin contains 33.8% fat, while breast meat contains only 6.7-8.3% fat.
  • Cooked chicken breast contains 1.3% fat, veal cutlets contain 11.0% fat, and beef cuts range from 13-30% fat.
  • Poultry meat has a higher proportion of unsaturated fatty acids compared to red meats and also contains less cholesterol.

Vitamins in Poultry Meat

• Poultry meat is rich in niacin and contains moderate amounts of riboflavin, thiamin, and ascorbic acid.
• Uncooked chicken liver is particularly high in vitamin A, thiamin, riboflavin, niacin, and ascorbic acid.
• Other edible parts of poultry also contain essential vitamins, although in smaller quantities compared to the liver.

Minerals in Poultry Meat

• Poultry meat is a good source of various minerals necessary for human nutrition.
• It includes sodium, potassium, magnesium, calcium, iron, phosphorus, sulfur, chlorine, and iodine, among others.
• The ash content in poultry meats ranges from 0.8 to 1.0 percent, with phosphorus, calcium, and iron being the major components.

Nutritional Benefits of Poultry Meat

• Poultry meat is considered an ideal food for individuals of all ages and various health conditions.
• It is recommended for infants, young children, adolescents, adults, elderly, convalescents, and those managing weight.
• The taste, tenderness, digestibility, and nutritional value make poultry a popular choice worldwide.

Preparation for Poultry Slaughter

• On the farm, preparation for slaughter begins at least a week in advance.
• Attention is given to the birds' diet to avoid harmful residues in the meat.
• Before slaughter, birds are deprived of food for a specific period to empty their digestive tracts.
• Care is taken during transportation to ensure the well-being of the birds, including protection from adverse weather conditions.
• Sick or injured poultry should not be transported and should be humanely euthanized on the farm.
• In the slaughterhouse, birds are processed humanely, including stunning with electricity and throat cutting.

Killing of Birds

• Most common method: Slaughtering birds by severing the jugular veins either from inside or outside.
• Cutting method: Large veins on both sides should be cut, either from inside or outside. Inside cut for pre-market birds, outside cut for ready-to-cook meat.
• Electric killing: Use of electric shock in large plants, but must be careful not to overdo it to ensure proper bleeding.

Bleeding Process

• Thorough bleeding: Poultry should be adequately bled after killing to ensure good quality meat.
• Bleeding duration: Takes 1 to 2 minutes depending on factors like age, size, and efficiency of the process.
• Procedure: Birds are allowed to bleed into containers or drain troughs before further processing.

Scalding Birds

• Scalding purpose: Submerging birds in hot water post-killing to ease feather removal process.
• Types of scalding: Hard Scald, Sub-scalding, Semi-scalding based on time and temperature for different bird types.
• Scalding water temperature: Governed by bird age, size, and scalding process used.

Picking Feathers

• Dry picking: Rarely used in commercial settings, more common in domestic consumption scenarios.
• Wet picking: Done by hand or mechanical pickers for efficient feather removal.
• Mechanical picking: Involves tools like revolving drums with rubber fingers for feather removal.

Poultry Processing Techniques

• Pinning

  • Pin feathers should be removed using a pinning knife by gripping them between the blade's edge and the thumb, then pulling outwards.
  • Scraping the pinning area is to be avoided as it can cause damage.
  • Proper scalding and feather picking help reduce pin feather issues.

• Singeing

  • To remove hair without harming the skin, a flame is quickly passed over the birds' surface.
  • A blower can be used for singeing as well.

• Cropping and Venting

  • These processes are unnecessary if the birds are to be eviscerated immediately. However, in some cases where birds are transported with viscera, crop and vent cleaning is required.
  • Removal of feed from the crop or making a small cut at the base of the neck may be necessary.
  • Washing is essential to remove fecal material and ensure cleanliness.

• Washing and Evisceration

  • After feather removal, cropping, and venting, thorough washing with water is crucial.
  • Evisceration should be done promptly for ready-to-cook birds to maintain quality.
  • Proper evisceration steps involve removing specific organs, washing the bird inside out, and preparing giblets for insertion.

• Cut-ups and Packaging

  • If the carcass is to be cut into pieces, chilling is necessary to ensure tenderness.
  • Various cuts like wings, breast, legs, and thighs require specific techniques for separation.
  • Inedible parts should be discarded, and a complete cut-up includes pieces like breast, wings, legs, back, neck, gizzard, heart, and liver.
  • Eviscerated birds are typically packed in specific boxes to maintain freshness and prevent contamination during transportation.

Slaughtering Techniques

• Large-scale slaughtering involves suspending the bird, stunning it, and then cutting the throat with a knife.
• The stunning apparatus can be high voltage or low voltage, inducing an electroplectic fit in the bird.
• Proper stunning is crucial to ensure effective bleeding and death within 30 seconds.

Automatic Machinery

• Modern automatic machinery like automatic neck cutters are used in slaughter plants for efficiency.
• These machines guide the bird's neck past a revolving knife blade wheel for a precise incision.

Feather Removal

• Feather removal is done by immersing birds in a scald tank of hot water to loosen the feathers.
• Plucking machines with rubber fingers remove feathers without damaging the carcass.
• Remaining feathers are removed by singeing or waxing processes. The carcass is then washed.

Evisceration

• Evisceration involves removing organs from the bird's cavities for inspection and processing.
• Organs like the head, neck, and associated tissues are removed over a trough with flowing water.

Head and Neck Removal

• The skin is loosened, and the trachea, esophagus, and crop are freed before head removal.
• The neck is then cut or pulled, ensuring thorough removal of organs and tissues.

Organ Removal Process

• Cuts are made around the vent to free the cloaca and the terminal part of the large intestine.
• Special care is taken to avoid damage to the cloaca during this process.

Summary of Venting and Evisceration Process in Poultry Processing

• Venting Process

  • Special tools like vent cutters are used to make a circular cut around the vent of the bird.
  • By using a vacuum, the cloaca and part of the large intestine can be left outside the bird.
  • A third cut is made cranially from the vent opening towards the tip of the breast bone without cutting the intestinal tract.

• Evisceration Process

  • Evisceration can be done manually, with special tools, or automatically using machines.
  • The intestine, gizzard, heart, liver, spleen, and sometimes lungs are removed from the cavity.
  • The oesophagus and proventriculus are stretched but not cut or split.
  • An automatic eviscerating machine can be used, and equipment is designed to synchronize operations for efficiency.

• Detailed Inspection and Processing

  • After evisceration, the carcase undergoes detailed inspection.
  • The liver and heart are removed from the viscera, washed, and prepared for further processing.
  • The gall bladder is removed, dried, and washed under a spray.
  • The alimentary tract is cut, releasing thoracic and abdominal parts.

• Cleaning and Final Checks

  • The gizzard is opened, washed, and its internal lining layer is removed.
  • If lungs remain, they are removed; otherwise, they are discarded with the intestine.
  • A thorough spray wash ensures all remnants are removed from the carcase.

Giblets Processing and Inspection in Poultry Industry

• Giblets Processing

  • Edible offal like hearts, livers, gizzards, and necks, known as giblets, undergo several processing stages.
  • Giblets are initially spray washed and then further washed in individual tanks.
  • After washing, they are chilled and packed into polythene or paper packets, usually containing a heart, liver, gizzard, and neck.
  • Giblets can be packed in flaked ice, with ice layers between giblet packs.
  • Packed giblets are inserted into the carcase's cavity or stored in a chill room to maintain a low temperature.

• Inspection Process

  • Veterinarians or trained inspectors oversee poultry meat inspections under veterinary supervision.
  • Various stages of inspection include:
  • 
    
    • Whole carcase inspection after washing post-defeathering.
    • Inspection during the evisceration process.
    • Inspection of organs like heart, liver, intestines, gizzard, spleen, and lungs.
    • Palpation to detect any bone or joint abnormalities.
    • Final inspection of the carcase for overall condition and abnormalities.

Handling of Diseased Carcasses

• Infected carcases are typically taken off the processing line for later evaluation.
• Some inspectors advocate for a division of labor where one inspects the offal and another examines the carcase.
• If a carcase is missing all viscera, it cannot be approved for human consumption. However, if only some viscera are absent, the inspector can use discretion based on the overall health of the flock to decide whether to pass or condemn the carcase.

Preservation of Poultry Meat and Products

• The initial step involves chilling the poultry meat, which can be done through water chilling or air chilling.

Air Chilling Process

• Birds are hung on racks and placed in a room maintained at a chill temperature, typically around 0°C.
• After initial chilling, giblets are washed, chilled, and wrapped in plastic before being put inside the carcase, which is then prepared for trussing.
• The trussed carcase is graded, weighed, tagged, placed in a polythene bag, sealed, and prepared for further processing before sale.

Final Cooling Stage

• The final cooling of the 'chilled' carcase occurs in a refrigerated room until the deep muscle temperature reaches 0°C.
• During cooling, the product is kept in a plastic basket or cardboard box, which will later be loaded onto a lorry for transport.
• In some regions, carcases are repacked and transported in ice, facilitating drainage through holes in the boxes.

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• Water Chilling:
  • Method used to initially chill carcases for deep freezing by cold water and ice.
  • Common method: continuous water immersion chilling with at least two tanks in series.
  • Precaution: Carcases should not stay in the chiller too long to avoid excessive water absorption.
  • Hygiene control: Maintained through water overflow and chlorine levels.
  • After chilling, carcases are hung on a conveyor until excess water drips away.
  • For deep-frozen products, water-chilled carcases are flash-frozen at -40°C for 2-3 hours and stored in cold storage rooms.
  • Cold storage rooms have separate chambers for other commodities like fish.
• Liquid Carbon Dioxide Chilling:
  • New method of chilling carcases using liquid carbon dioxide.
• Legal and BIS Standards:
  • Quality standards for live poultry on an individual bird basis are provided in Table 5.
• Grading Characteristics of Dressed Chicken (I.S.):
  • Grade I:
    • Free of deformities affecting appearance or flesh distribution.
    • Criteria for conformation, fleshing, fat covering, defeathering, cuts, tears, and discoloration.
  • Grade II:
    • Criteria for breast, fat distribution, cuts, tears, discoloration, and freezer burn.
    • Specifications for grading carcases according to I.S.I. standards in Table 5.

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• Brilliant Tutorials:
  • Minor abnormalities like dented or curved bone do not significantly impact flesh distribution.
• A.A.T.:
  • Criteria for breast flesh, fat distribution, pin feathers, cuts, tears, and discoloration.
  • Specifications for discolored areas, cuts, tears, and freezer burn.
• Lamp:
  • Grading done post-inspection based on I.S.I. specifications in Table 5.

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