Technology of Processed MeatFST-717 3(2-1)

Dr. Muhammad Issa KhanAssociate Professor (Tenured)

National Institute of Food Science and Technology

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.

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

• 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.

• 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

• 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

• 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

• 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

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

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

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

• 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

• 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

Live Production-Related Factors Contributing to Carcass Contamination

• 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

• 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

• 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

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

• 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