This document discusses the processing of poultry meat. It covers the key steps in poultry processing including receiving, stunning, bleeding, scalding, defeathering, evisceration. It then discusses factors that can affect meat quality preslaughter like genetics, nutrition, management, and stress during harvesting and transport. Specifically, it focuses on how lighting, cooping of birds, and environmental temperature can impact crop emptying and the risk of fecal contamination during processing if the digestive tract is not fully emptied. Maintaining optimal conditions and feed withdrawal times is important to reduce contamination.
1. Technology of Processed Meat
FST-717 3(2-1)
Dr. Muhammad Issa Khan
Associate Professor (Tenured)
National Institute of Food Science and Technology
2. Theory
• Processing of poultry meat: receiving and weighing, stunning,
bleeding, scalding, de-feathering, evisceration operations. Curing
of meat: ingredients, types, methods. Meat smoking: purpose,
production, deposition of smoke on meats, methods of smoking,
liquid smoke preparation and its application. Meat cookery and
cooked meat products: action of cooking, methods. Sausages:
classification, formulations, processing steps, fermented meat
products, sausage products. Reduced & low fat meat products:
effect of reducing fat, synthetic fat replacers, fat mimics,
frankfurters. Canned meat: formulations, process. Restructured
meat products: procedures, raw materials, formulations.
Development of functional meat products.
Practical
• Local meat products and cookery: Beef stews, chili, sausages,
meat balls with gravy, sliced dried beef, potted meat, smoked
meat & other meat products, restructured meat products. Visits to
the meat/poultry processing industries.
3. Processing of Poultry Meat
• Poultry processing is a complex combination of biology,
chemistry, engineering, marketing, and economics
• Producing human food is the main goal of poultry processing,
related fields include waste management, non-food uses of
poultry, and pet/livestock feeds
• Considering the global marketplace, poultry refers to any
domesticated avian species, and poultry products can range from
a slaughtered carcass to a highly refined product such as a
frankfurter or nugget
• Commercial poultry is extremely uniform in appearance and
composition
• Tightly managed breeding, incubation, rearing, and nutritional
regimes have created a bird that is a virtual copy of its siblings
4. • This uniformity has allowed poultry processing plants to
develop into highly automated facilities with an efficiency
that is unmatched by other livestock processors
• Line speeds of 70 to 140 chickens/min, uniformity,
automation, and efficiency are recurring themes and have
been keys to the success of poultry processing.
5.
6. • Poultry companies in the U.S. are vertically integrated
• This is a system in which the same entity (e.g., company,
cooperative, etc.) owns several (or all) steps of the
production process from breeding through processing
• Vertical integration ensures maximum efficiency and
uniformity
• By reducing the number of times a component of the
production system (feed, chick, labor, etc.) changes
ownership, the profit charged at each level of change can
be eliminated
• Some poultry companies have taken the concept of vertical
integration to a higher level by growing their own grain
and purchasing interests in the breeding companies
7. • Improved uniformity is another benefit that results from all
parts of the production system having a common goal, a
common set of specifications, and a common system of
oversight
• The poultry industry is rapidly becoming global
• Poultry meat consumption has dramatically increased in
recent decades to the point where it has the largest per
capita consumption of any meat type
• Several factors have contributed to this increased appeal of
poultry
• First, the fat in poultry is almost exclusively associated
with the skin and is easy to remove in response to dietary
guidelines for reducing dietary fat
8. • Second, the industry has been very responsive in
developing new products to meet the changing consumer
needs
• Poultry meat is more homogeneous in composition, texture,
and color than mammalian meat, making poultry easier to
consistently formulate into products
• When compared to beef, poultry meat also has a milder
flavor which is more readily complemented with flavorings
and sauces
• Economic production through vertical integration,
favorable meat characteristics, and product innovations to
meet consumer needs have all contributed to the poultry
industry’s success
9. • The safety of poultry products and the use of water in
processing are two issues with which the industry is
concerned
• Developments in live bird production, processing plant
operations, product characteristics, and inspection systems
are all being made to reduce bacterial contamination on the
product and improve the product’s safety
• The expense and environmental impact of using large
quantities of water in processing and then cleaning that
water before discharging it have all prompted intense study
in these areas
10. Preslaughter factors affecting poultry meat quality
• Antemortem factors affecting poultry meat quality may be
divided into two categories: those having a long term
effect and those having a short term effect
• Long term factors are inherent, or they occur over the entire
length of the bird’s life, such as genetics, physiology,
nutrition, management, and disease
• Short term factors affecting poultry meat quality are those
that occur during the last 24 hours that the bird is alive,
such as harvesting, transportation, plant holding, unloading,
shackling, immobilization, stunning, and killing
11. Harvesting
• Birds are generally reared on litter in enclosed houses, with
approximately 20,000 broilers per house or 6000 to 14,000
turkeys per house, depending on house size
• Bird age at slaughter depends upon the end product, but the
majority of broilers are processed between the ages of 6
and 7 weeks, while turkeys are processed between 14 and
20 weeks of age
• Birds must be “harvested” before they can be processed,
and this involves preparing birds for catching or collection,
catching birds, and placing birds into containers
• Some of the major preslaughter problems that may occur
include bird injuries, bird mortality, and bird weight loss
due to feed and water deprivation
12. Feed withdrawal
• Before birds are caught, loaded, and transported to the
processing plant, feed and water are removed to allow time
for evacuation of intestinal contents
• Feed withdrawal, reduces incidence of carcass fecal
contamination which may occur during processing
• USDA’s requirement of zero tolerance of carcass fecal
contamination in the Pathogen Reduction/Hazard Analysis
and Critical Control Point System (HACCP) ruling, length
of feed withdrawal has become more important to the
poultry industry
• Zero tolerance of feces means that carcasses contaminated
with visible feces are not allowed to enter the immersion
chiller
13. • Numerous factors influence the effectiveness of a
commercial feed withdrawal program, making it extremely
difficult to optimize such a program
• Feed withdrawal refers to the total length of time the bird is
without feed before processing
• This includes the time the birds are in the grow-out house
without feed, as well as the time the birds are in transit and
in the live hold area at the processing plant
• Length of feed withdrawal is important because it affects
carcass contamination and yield, grower payments,
processing plant line efficiency, and product safety and
quality
• The length of feed withdrawal before processing should be
the shortest amount of time required for the birds’ digestive
tracts to become empty
14. • However, this time varies because of differences in house
environmental conditions and management practices which
affect bird eating patterns
• Recommended length of time off feed for broilers before
processing is between 8 to 12 hours, while 6 to 12 hours is
recommended for turkeys
Live production management
• Lighting (intensity and duration) and cooping have been
found to affect bird activity, and activity of birds affects the
rate of feed passage
• Under continuous light and access to water, 60 to 70% of
the intestinal contents will be evacuated during the first 4 to
6 hours of feed withdrawal
16. • When birds are exposed to darkness, or after birds are
cooped, the evacuation rate is much slower
• Research has shown that after a 2-hour feed withdrawal
period, broilers in a dark environment had more feed in
their crops than broilers in lighted environments
• After 4 hours of feed withdrawal, lighting made no
difference in crop contents, except when it was combined
with cooping
• Cooped broilers held in darkness for 2 hours had more than
twice as much feed in their crops than cooped broilers held
in the light
• In addition, after 4 hours of feed withdrawal, there was
twice as much feed within the crops of broilers held in
darkness compared to crops of broilers held in light
17. • For this reason, poultry companies usually leave birds in
the grow-out house on litter with water, but not feed, for 2
to 5 hours before catching
• It has been suggested that 4 hours of water consumption
for broilers and 2 hours of water consumption for turkeys
is optimal after feed withdrawal to allow feed passage from
the crop
• Longer time on water may cause excessive moisture in the
intestinal tract, which increases the likelihood of carcass
contamination during evisceration
Environmental temperature
• In addition to lighting and cooping, environmental
temperatures have been shown to affect digestive tract
clearance of broilers during feed withdrawal
18. • This may be related to the consumption of less feed during
hot weather in conjunction with reduced bird activity
• During the fall and spring when daily temperatures vary
widely, birds may gorge themselves in the evening after the
sun goes down and temperatures begin to decline
• If birds have gorged immediately before feed withdrawal, a
normal withdrawal period may not be long enough
• Birds grown during cold weather with house temperatures
below 15.5°C also retain feed in their digestive tracts longer
• When birds do not have normal eating patterns, there is
greater variability in the content and condition of their
digestive tracts
19. Carcass contamination
• Fecal contamination of broiler carcasses occurs when the
contents of the bird’s crop or digestive tract leak onto the
carcass, or intestines are cut or ruptured during
evisceration
• When contamination occurs, affected carcasses are
removed from the processing line for manual reprocessing
(washing, trimming and vacuuming), followed by re-
inspection
• Carcass reprocessing and re-inspection delay the operation
of the processing plant and increase the cost of producing a
quality product, especially when flocks come through with
a high percentage of contamination
20. • Frequency of carcass contamination depends upon;
The amount of material present in the digestive tract
The condition of the digesta (partially digested food and
feces) remaining in the intestines (watery or firm)
The integrity of the intestines
The efficiency of the eviscerating equipment and plant
personnel