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which greatly limits its potential uses. Some poultry

meat, especially that of mature hens, is cooked prior

to hand deboning.

0045 After the major muscles are deboned from the car-

cass, the remaining frames (also necks, backs, and

low-value parts) can be more completely deboned

by special machines. In the first stage of mechanical

deboning, a grinder reduces bone and meat particle

size. In the second step, a pressure system squeezes the

ground meat and bone against a perforated screen or

microgrooved cylinder. Advances in mechanical

deboning have eliminated pregrinding and produced

a more texturally attractive product. An alternative

system is a batch operation. Pressure from a ram

forces meat to flow from the bones through a sieve

screen; the bone cake is ejected, and a new batch is

introduced.

Further-Processed Products

0046 Much of the hand- and mechanically deboned chicken

meat is directed into value-added products. Deboned

meat can be marketed ‘as is’ fresh, as whole breast or

split breast fillets, strips, and chunks. Alternatively,

deboned meat can be tumbled, marinated, chopped,

formed, ground, emulsified, or prepared in a number

of ways for sale.

0047 Many nonmeat ingredients are used in further pro-

cessing. Salt helps to extract proteins for improved

binding and texture, acts as a preservative, and en-

hances flavor. Up to 0.5% phosphate increases water-

holding capacity and final product yield. Other

ingredients, such as sweeteners, spices, binders, and

curing salts, are used in the wide array of poultry

products on the market. (See Curing.)

0048 The driving force behind poultry product develop-

ment is the consumer. Fat content in meats is a current

concern; many people want healthier diets, and the

low fat in poultry is a major reason for its popularity.

Fat pads are removed from many whole carcasses in

response to consumer desires. As new poultry prod-

ucts are designed, diet and health, microwave ovens,

and an aging population cannot be ignored.

0049 The fast-food restaurants have had a tremendous

influence on new poultry product popularity for items

such as nuggets, tenders, marinated breast fillets, and

frozen–fried parts. Ethnic foods are popular in the

USA, especially Italian, Mexican, and Chinese. Dif-

ferent flavors in poultry products are in demand,

including cajun, barbecue, and honey. Spicy chicken

wings are an example of a popular seasoned finger-

food appetizer. In addition to less fat, smaller por-

tions, and different flavors, consumers want less

salt and cholesterol in their chicken products. The

food must be of high quality, convenient, safe, and

nutritious.

0050In the retail supermarket, low-fat chicken products

such as patties, rolls, sausages, and sliced luncheon

meats are selling well. Poultry frankfurters and bol-

ogna are generally lower in fat than similar red-meat

products and are a healthy alternative. (See Meat:

Sausages and Comminuted Products.)

0051Most recent entries among the new poultry prod-

ucts are boneless chicken breasts stuffed with ingredi-

ents such as cheese and broccoli or wild rice and

mushrooms. These products are sold in a variety of

packages and combinations, but are almost always

ready for cooking in the microwave. Other gourmet

items include chicken Kiev (breaded chicken breasts

filled with garlic butter and parsley), chicken cordon

bleu (filled with ham and cheese), and herb-roasted

chicken dinner (low-fat, low-cholesterol, low-sodium

meal). Even the luncheon market has new chicken

‘lunchable’ products, which are individual packages

containing items such as cooked sliced poultry, cheese

slices, and crackers.

Microbiological Concerns

0052Modern poultry husbandry and processing tech-

niques have greatly improved the quality of poultry

meat. However, chicken can carry many kinds of

organisms. The two major concerns are control of

spoilage organisms which cause consumers to reject

the product due to odor or flavor, and the minimiza-

tion of pathogenic organisms which may (under

faulty handling) lead to a health hazard.

Spoilage Microorganisms

0053Although poultry is refrigerated, and even frozen, for

shelf-life extension, spoilage will invariably occur

owing to the growth and metabolic activities of spe-

cific types of bacteria. The psychrophiles, such as

Pseudomonas, can generally grow at refrigerator tem-

peratures and are responsible for most of the spoilage.

Spoilage organisms are present in high numbers when

an off-odor becomes apparent (10

cells per cm

) and

even greater when slime formation occurs from co-

alescence of colonies (c.10

cells per cm

). (See Spoil-

age: Bacterial Spoilage.)

Pathogenic Microorganisms

0054Poultry is considered to be a major source of Salmon-

ella, which can spread during processing, and even

after cooking if raw meat preparation surfaces

were not cleaned before placing a cooked product

on the same surface. However, normal cooking

procedures destroy Salmonella and it will not grow

well under refrigeration. The most common problems

are undercooked poultry or poultry contaminated

after cooking. According to data on the vehicle of

POULTRY/Chicken 4685

foodborne salmonellosis outbreaks in the USA

between 1973 and 1987, only 3.8% (30 of 790) of

the cases were caused by chicken.

0055 In addition to Salmonella, other pathogens some-

times found in poultry include staphylococci, Cam-

pylobacter, Listeria spp., clostridia, and coliforms.

Careful product handling, proper refrigeration,

and adequate cooking will almost always insure

product safety. (See Campylobacter: Campylobacter-

iosis; Clostridium: Food Poisoning by Clostridium

perfringens; Botulism; Listeria: Listeriosis; Staphylo-

coccus: Food Poisoning.)

Sources of Bacteria

0056 Microbes in poultry-processing plants are ultimately

found on the product and come from three main

sources: the birds (feet, feathers, intestinal contents),

the environment (water, air, supplies), and the

workers. Careful management at the production site

and adherence to good manufacturing practices at the

processing plant (e.g., filtered air, cool temperatures,

thorough cleaning and sanitation, and good worker

hygiene) will minimize final product contamination

with bacteria.

See also: Amino Acids: Properties and Occurrence;

Campylobacter: Campylobacteriosis; Cholesterol:

Properties and Determination; Clostridium: Food

Poisoning by Clostridium perfringens; Botulism; Curing;

Effluents from Food Processing: Disposal of Waste

Water; Composition and Analysis; Fatty Acids:

Properties; Listeria: Listeriosis; Meat: Slaughter;

Preservation; Sausages and Comminuted Products;

Sodium: Properties and Determination; Spoilage:

Bacterial Spoilage; Staphylococcus: Food Poisoning

Further Reading

Anonymous (1990) Broiler Industry Marketing Practices,

Calendar Year 1989. Washington, DC: National Broiler

Council.

Bean NH and Griffin PM (1990) Foodborne disease out-

breaks in the United States, 1973–1987: pathogens,

vehicles, and trends. Journal of Food Protection 53(9):

804–817.

Brant AW, Goble JW, Hamann JA, Waback CA and Walters

RE (1982) Guidelines for Establishing and Operating

Broiler Processing Plants. Agriculture Handbook 581.

Washington, DC: Agricultural Research Service, US

Department of Agriculture.

Cunningham FE and Cox NA (1987) The Microbiology of

Poultry Meat Products. Orlando: Academic Press.

Mead GC (1989) Processing of Poultry. Essex: Elsevier

Science.

Mountney GW (1976) Poultry Products Technology, 2nd

edn. Westport, CT: AVI.

North MO (1984) Commercial Chicken Production

Manual, 3rd edn. Westport, CT: AVI.

Posati LP (1979) Composition of Foods. Poultry Products,

Raw, Processed, Prepared. Agriculture Handbook 8–5.

Washington, DC: Science and Education Administra-

tion, US Department of Agriculture.

Putnam JJ (1990) Food Consumption, Prices, and Expend-

itures, 1967–88. Statistical bulletin no. 804. Washing-

ton, DC: Economic Research Service, US Department of

Agriculture.

Stadelman WJ, Olson VM, Shemwell GA and Pasch S

(1988) Egg and Poultry-Meat Processing. Cambridge:

VCH.

Ducks and Geese

A J Maurer

, Formerly of University of Wisconsin-

Madison, Madison, WI, USA

This article is reproduced from Encyclopaedia of Food Science,

Introduction

0001Ducks and geese (waterfowl) are a delicacy to many

people, while others object to the higher amounts of

fat in the carcasses compared to broilers and turkeys.

However, breeding and mass selection programs are

improving the meat-to-bone and meat-to-fat ratios

in waterfowl. Annual duck consumption on a ready-

to-cook basis in the USA is only about 0.2 kg per

person. Goose consumption is somewhat less, at ap-

proximately 0.01 kg per person per year. Although

chickens and turkeys dominate the world poultry

industry, in parts of Asia ducks are commercially

more important than broilers (chickens), and there

are more geese than turkeys in areas of Europe. This

article reviews duck and goose processing and prep-

aration, meat composition and nutrition, food uses

and products, waste products, and microbiological

problems.

Processing and Preparation

0002With a few exceptions, duck and goose processing is

similar to that of broilers and turkeys. For a more

complete slaughter and evisceration procedure, (See

Poultry: Chicken.)

0003In the USA, White Pekin-type ducks are generally

slaughtered at 7 weeks of age and weigh about 3.2 kg

live. White Muscovy ducks are also raised for meat,

but they are a slower-growing breed and commercially

Deceased.

4686 POULTRY/Ducks and Geese

less popular than the White Pekin. Geese are 3–5

months old at slaughter, and their average live weight

is 4.5–6.8 kg. The average ready-to-cook weight of

geese varies, but is generally about 4.5–5 kg. Feather

maturity (lack of pinfeathers) is an important factor

in determining the best time to slaughter waterfowl.

(See Meat: Slaughter.)

0004 Processors transport ducks and geese to slaughter

plants on open trucks or trailers. The loading and

unloading process is unique as the birds are not usu-

ally caught by their legs; they are herded on to the

conveyance, and off into holding pens at the process-

ing plant. Processors use turkey-sized crates when

there are relatively few geese to transport.

0005 Ducks and geese are driven from holding pens

through chutes on to scales for weighing and then

into the shackle hanging area. Care in herding

the waterfowl is essential to avoid pile-ups, skin

scratches, damaged legs, and smothered birds.

0006 It is important to minimize struggling by the birds

when hanging them on motorized conveyor line

shackles as excessive flapping can result in bruises.

In smaller processing plants, killing funnels can be

used to restrain and position the birds for slaughter.

0007 The birds are usually stunned with an electric cur-

rent and then bled. Sometimes a cut inside the mouth

is used, but a common method of killing the birds is to

cut the outside of the throat on the left side at the base

of the jaw, severing the left jugular vein and carotid

artery.

0008 Following bleeding, both ducks and geese can be

scalded or dry-picked. However, the latter method

is slow and laborious. Generally, ducklings proceed

through immersion scalders containing agitated

water at 58–63



C. Geese can be scalded in a similar

commercial scalder, or they can be hand-scalded for a

smallscale operation. Scald water temperature for

geese should be 63–66



C. The duration of the scald

varies from 1.5 to 3 min, usually longer for geese

than for ducks. The time and temperature will also

change depending on the age of the bird, time of

year (season), and density of feathering. The lower

the temperature, the longer the scald. A little deter-

gent or an alkaline defeathering agent can be added

to facilitate thorough wetting of the feathers. Proces-

sors can hand-scald waterfowl by pulling the bird

repeatedly through the water against the lay of the

feathers.

0009 After scalding, the birds may be rough-picked

by hand, picked by a conventional rubber-fingered

picking machine (online), or placed in a spinner-type

picker. Because pins and down remaining on the

carcass are difficult to remove, it is common practice

to finish rough-picked birds by dipping each bird into

melted wax specially formulated for this purpose.

0010The defeathered birds should be surface-dried (a jet

of compressed air can be used) just long enough to

allow the wax to adhere. The waxing operation is

usually mechanized and often includes conveying

the ducks in and out of two wax tanks. A resin-

based microcrystalline wax is used for greater resili-

ence and improved stripping.

0011Good wax penetration and adhesion are achieved

in the first tank with immersion in 90



C wax for 15 s.

The second wax dip at 71



C puts a heavier coating on

the birds to thicken the wax for good pulling power

and cleaner stripping. After waxing (and sometimes

between wax dips), a cold-water spray over the birds

or a dip into a tank of cold water will cool and harden

the wax to a tacky state. The wax is then removed by

hand or by a rubber-fingered wax stripper. Some

processing plants dip the wax-picked birds into

water at 82



C to tighten the skin for easier manual

removal of any remaining pinfeathers. Grasping pin-

feathers between the thumb and a dull knife will assist

in this operation.

0012The wax is reclaimed by remelting and straining

out the pins, down, and feathers. Occasionally, the

used wax should be ‘cooked down’ to remove all

water that may have been mixed with it by emulsion.

0013After completely removing feathers, pins, and

down, processors eviscerate the carcasses by making

an opening cut in the abdomen and pulling out the

viscera. Waterfowl viscera are somewhat difficult to

withdraw, so that evisceration is most often done

manually. However, processing plants in Europe are

using automatic duck evisceration and automatic

head and trachea pulling with processing rates of

4000 ducklings per h.

0014Each carcass on the eviscerating line is inspected

for wholesomeness before the withdrawn viscera are

detached. After the inedible viscera and lungs are

discarded, the heads, tracheas, and feet are removed;

the giblets are cleaned and wrapped for later place-

ment in the body cavity. In many processing plants,

only the two lobes are cut from gizzards because the

inner lining is difficult to peel.

0015Following evisceration, birds receive an inside and

outside spray wash before proceeding through a

chilling treatment of cold tap water or ice and water.

Airagitated cooling vats, a continuous immersion

chiller, or air-spray chilling can be used.

0016After carcass cooling and draining in commercial

waterfowl plants, each carcass is graded for conform-

ation, fleshing, fat covering, and defects such as

pinfeathers and exposed flesh. Processors then

vacuum-package carcasses in barrier bags, heat-

shrink the bags, and quick-freeze the packaged car-

casses. Young ducks and geese may also be sold fresh,

unfrozen. (See Meat: Preservation.)

POULTRY/Ducks and Geese 4687

Composition and Nutrition

0017 Dressing percentages and meat yield of ducks and

geese will vary with breed, age, sex, weight, and

grade. The processing loss from live to ready-to-cook

(carcass, neck, and giblets) for ducks is approximately

30%, 25–32% for geese, and 24% for broilers.

0018 As the data in Table 1 show, raw ducks and geese

contain more fat, less water, and less protein than are

found in broiler chickens. Roasting causes fat and

some water loss, thereby concentrating (increasing)

the protein content. Because of the relatively high fat

content of waterfowl, the carcasses become rancid

more easily, and frozen shelf-life is shorter than that

of broilers or turkeys. (See Fats: Digestion, Absorp-

tion, and Transport; Protein: Food Sources.)

0019 Skinning the carcass can remove much of the fat in

poultry. For example, the fat content of raw duckling

meat with skin is 39.3%; without skin, it is 6.0%.

Values for goose are 33.6% with skin and 7.1%

without skin. The fat in ducks and geese is highly

unsaturated, as is the case in all poultry. Duck and

goose skin (including separable fat) makes up 34–

38% of the ready-to-cook carcass, but broiler skin is

about 15% of the carcass. Conversely, the meat yield

from ready-to-cook carcasses for ducks and geese is

34–47%, compared to 52% for broilers.

0020 Duck is a good source of thiamin, and goose is an

excellent source of phosphorus. The other vitamins

and minerals are also present in ample amounts. Iron

content is especially high in waterfowl, contributing

to the darker color of the breast meat. (See Phos-

phorus: Properties and Determination; Thiamin:

Properties and Determination.)

Food Uses and Products

0021 Most duck and goose meat is consumed in whole

carcass form. The carcasses are roasted in the same

way as other poultry, but they yield less cooked edible

meat. Because waterfowl contain more fat than

broilers or turkeys, they do not require basting during

roasting. If the carcasses are excessively fat, it helps

to puncture or scratch the skin to permit some fat

to cook out during roasting. Thorough cooking of

waterfowl (to an internal temperature of at least



C) is important to attain a crispy skin and for

complete customer satisfaction.

0022Food manufacturers sell some further-processed

waterfowl products. Duckling breast portions, semi-

boneless halves, marinated breasts, fully cooked roast

half duckling, and other gourmet items are available

to the institutional trade. A few shops market spe-

cialty duck and goose products, such as smoked duck,

boneless breast of duckling, smoked goose leg, or

goose liver sausage.

0023Goose livers are popular in delicacies such as pa

de foie gras; the product must contain at least 30%

goose liver. For a period of time in Europe and in

parts of the USA, many people force-fed, or noodled,

their geese. The starchy noodling ingredients (corn,

wheat, barley, and rye) used in this frequent forced

feeding produced an extra large liver (weighing nearly

1 kg each), which was sold at premium prices.

0024Goose fat is sometimes used in place of butter. It

can also be used in frying, baking, cooking, and prep-

aration of gravies, broths, and soups.

Waste Products

0025Duck and goose slaughtering produces the usual

waste products of blood, feathers, feet, heads, ined-

ible viscera, grease, debris, and cleaning water. The

control and handling of these waste materials depend

on the standards set by individual countries and local

authorities. The methods of handling can include

disposal to a public sewer after the fat and as many

solids as possible have been removed, or treatment

tbl0001 Table 1 Proximate analysis of ducks, geese, and broilers (100 g edible portion, wet-weight basis)

Nutrient Duck meat

with skin (raw)

Duck meat

with skin (roasted)

Goosemeat

with skin (raw)

Goosemeat

with skin (roasted)

Broiler meat

with skin (raw)

Water (g) 48.50 51.84 49.66 51.95 65.99

Protein (g) 11.49 18.99 15.86 25.16 18.60

Energy (kJ) 1697 1415 1558 1281 903

Lipid

Total (g) 39.34 28.35 33.62 21.92 15.06

Saturated (g) 13.22 9.67 9.78 6.87 4.31

Unsaturated (g) 23.77 16.55 21.53 12.77 9.47

Cholesterol (mg) 76 84 80 91 75

Ash (g) 0.68 0.82 0.87 0.97 0.79

Sodium (mg) 63 59 73 70 70

Reproduced from Posati LP (1979) Composition of Foods. Poultry Products, Raw, Processed, Prepared. Agriculture Handbook 8–5. Washington, DC: Science

and Education Administration, US Department of Agriculture.

4688 POULTRY/Ducks and Geese

on-site and disposal of the filtered effluent to a lagoon

or spray irrigation system.

0026 In general, the first stage of any effluent system is

the removal of coarse solids by screening. A fat trap

or dissolved air flotation can then remove fine solids,

fat, and grease. The effluent is further cleaned by

either anaerobic digestion or aeration. (See Effluents

from Food Processing: Composition and Analysis;

Disposal of Waste Water.)

0027 In contrast to other poultry-processing waste treat-

ment problems, ducks and geese provide several valu-

able byproducts. The Far East is a good market for

frozen duck feet, where they are stuffed with pork

and considered a delicacy. Duck tongues are also

valued by orientals as hors d’oeuvres. Some parts

(heads and offal) go into mink or other animal food.

0028 Other important byproducts are duck and goose

down and feathers, used chiefly by the bedding and

clothing industries. The poultry slaughter plant rinses

and centrifuges the wet feathers to decrease the water

content prior to shipping them to a feather-processing

plant. A machine separates the down (15–25% of the

feather mixture) and feathers, and washes and dries

them. About five ducklings or three goslings are

needed to produce 0.45 kg of dry feathers.

0029 On a smaller scale, home processors can wash

feathers in soft, lukewarm water which includes

either a mild detergent or a little borax and washing

soda. After rinsing, feathers are spread out to dry.

Microbiological Problems

0030 In general, microbiological problems in ducks and

geese are similar to those in other poultry. Pseudo-

monads are the main spoilage organisms. However,

because of the very low duck and goose meat con-

sumption, few illnesses have been attributed to water-

fowl. The combination of scalding at 60



C, followed

by immersion in molten wax at c.90



C to aid final

removal of feathers, appears to have a beneficial

effect on the microbial quality of the finished product.

(See Spoilage: Bacterial Spoilage.)

See also: Effluents from Food Processing: Disposal of

Waste Water; Composition and Analysis; Fats: Digestion,

Absorption, and Transport; Meat: Slaughter;

Preservation; Phosphorus: Properties and

Determination; Poultry: Chicken; Protein: Food Sources;

Spoilage: Bacterial Spoilage; Thiamin: Properties and

Determination

Further Reading

Baeza E, Dessay C, Wacrenier N, Marche G and Listrat A

(2002) Effect of selection for improved body weight and

composition on muscle and meat characteristics in Mus-

covy duck. British Poultry Science 43(4): 560–568.

Cunningham FE and Cox NA (1987) The Microbiology of

Poultry Meat Products. Orlando: Academic Press.

Franson JC, Hoffman DJ and Schmutz JA (2002) Blood

selenium concentrations and enzyme activities related to

glutathione metabolism in wild emperor geese. Environ-

mental Toxicology and Chemistry 21(10): 2179–2184.

Mead GC (1989) Processing of Poultry. Essex: Elsevier

Science.

Mountney GW (1976) Poultry Products Technology, 2nd

edn. Westport, CT: AVI.

Orr HL (1978) Duck and Goose Raising. Publication 532.

Ontario: Ministry of Agriculture and Food.

Posati LP (1979) Composition of Foods. Poultry Products,

Raw, Processed, Prepared. Agriculture Handbook 8–5.

Washington, DC: Science and Education Administra-

tion, US Department of Agriculture.

Stadelman WJ, Olson VM, Shemwell GA and Pasch S

(1988) Egg and Poultry-Meat Processing. Cambridge:

VCH.

Turkey

A J Maurer

, formerly of University of Wisconsin-

Madison, Madison, WI, USA

This article is reproduced from Encyclopaedia of Food Science,

Introduction

0001Chickens and turkeys dominate the world poultry

industry. The increasing popularity of poultry meat,

including turkey, comes from low cost (value for

money), a healthy nutritious image, and availability

in a variety of convenient forms. Efficiencies in inte-

grated turkey production, processing, and marketing

have helped maintain favorable retail prices. This

article reviews specific characteristics of turkey, pro-

cessing of turkeys, food uses and products, microbio-

logical concerns, waste products, and the nutritional

profile of turkey meats and products.

Specific Characteristics

0002Turkey consumption has increased in many countries

throughout the world, with Israel as the leader (over

9 kg per person in 1986). Less than one-third of this per

capital consumption (2.7 kg) is of whole-carcass birds.

Clearly, the growth in turkey popularity has come in

cut-up parts and more fully prepared products.

0003Turkey hens in the USA, sold at about 16 weeks of

age, provide almost 6 kg of ready-to-cook carcass.

Toms (male turkeys) are slightly older, at 20–24

Deceased.

POULTRY/Turkey 4689

weeks, and yield 10–12 kg of marketable carcasses.

Desirable characteristics of turkeys include heavy

bird weights without excess fat, a high dressing

yield, and an ample proportion of valuable parts.

The breast (white meat) is 35–40% of the ready-

to-cook carcass. Leg meat, 25–30% of the carcass,

contains more myoglobin and is darker than breast

meat.

0004 Other desirable turkey meat attributes include ten-

derness, bland flavor (allows further processing and

seasoning), and good functional properties, such as

protein extraction, protein gelation, water holding,

meat binding, and emulsification. Turkey meat is

similar to broiler meat in its composition and qual-

ities, easily digestible, high in protein, and low in fat.

Processing of Turkeys

0005 Turkey processing refers to slaughtering, feather re-

moval, evisceration, and chilling. Other operations,

such as inspection and packaging, are also important

steps in processing turkeys for market. Most of the

processing procedures are similar to those used for

broilers.

Procurement

0006 Special trailers or trucks with built-in cages haul

turkeys to the slaughter plant. If crates are used to

transport turkeys, they are considerably higher than

those used for chickens. Handlers must catch, load,

and unload turkeys very carefully to minimize bruises

and broken bones. Escalator-type loaders are some-

times used to elevate turkeys to the built-in truck

cages. The turkeys should be off feed 8–12 h prior to

slaughter to minimize fecal contamination in the pro-

cessing plant. Large-volume, slow-moving fans or

evaporative cooling provides good ventilation and

comfort for the birds in holding sheds at the process-

ing plant.

0007 Because turkeys are large and heavy, shackle line

height in the unloading area and truck cages must be

adjusted to the same level to minimize lifting required

by the hangers. Workers hang the turkeys by both feet

to the overhead moving shackles.

0008 A dimly lit hanging area discourages the birds from

struggling and flapping. Some processors install a

smooth plastic bar parallel to and slightly below the

overhead conveyor line so that the turkey’s breast

rubs against it to provide a soothing effect. The

turkeys should move from the hanging area to the

stunner within 6 min.

Stunning

0009 The shackle line drags the heads of the birds through

0.1–1.0% saline water which contains a submerged

electrode. Careful control of the voltage and current

is vital. Too little current will not immobilize the

birds, and too much current can cause a violent

muscle contraction, often resulting in broken clavicle

fragments in the muscle tissue.

Slaughter

0010Killing is usually performed manually by cutting across

the side of the neck at the base of the bird’s head,

severing a jugular vein and carotid artery. Bleed time

should be at least 2 min in a blood tunnel to collect the

blood for proper disposal. Workers in some turkey

slaughter plants cut both sides of the neck for more

complete bleeding. (See Meat: Slaughter.)

Scalding

0011After bleeding, processors scald turkeys by immersion

in agitated hot water to facilitate feather release. For

some fresh chilled markets, they semiscald turkeys at

50–52



C to retain the epidermal cuticle, which re-

duces skin dehydration. Most processors, however,

scald turkeys at approximately 60



C for 2–2.5 min.

The USA has a requirement for an overflow from the

scald tank of approximately 11 of water per bird to

help float debris from the water.

Defeathering

0012After scalding, the shackle line carries the birds

through a series of picking machines containing ro-

tating rubber fingers on disks or drums which rub or

pluck the feathers from the carcasses. Workers

remove the remaining pinfeathers by hand.

0013The birds pass through a gas flame to singe off the

filoplumes or hairs protruding from the skin surface.

The final process on the kill line is a thorough wash-

ing of the external surface of the carcass with pressur-

ized water jets.

0014The carcasses then pass through a shank-cutting

station. In some plants, an automatic tendon puller

removes the shanks and pulls up to nine of the main

sinews from the drumstick. At this point, a conveyor

transfers the carcasses from the killing, scalding, and

defeathering area into another room for evisceration.

Evisceration

0015For evisceration, turkeys hang from both legs with

their heads also placed in a center slot of the shackle,

creating a three-point suspension. This presents the

birds horizontally, breast-up, for easier cutting and

eviscerating. Plants equipped with mechanical evis-

cerating equipment use the two-point leg suspension.

0016Evisceration begins with an incision made through

the abdominal wall. The cut continues around the

vent and enlarges in the abdomen for easier removal

4690 POULTRY/Turkey

of the viscera. In some plants, a bar (transverse) cut in

the abdomen allows evisceration and later trussing of

the legs. A mechanical vent cutter with a revolving

cylindrical blade is another method to make an

opening cut and remove the vent.

0017 Processors withdraw the viscera through the ab-

dominal opening, taking special care to avoid dam-

aging the intestines or spilling the contents. The

viscera are left attached to the carcass and draped

over the outside of the bird for inspection. An in-

spector then examines each bird (inside, outside,

and viscera) for wholesomeness. Carcasses can be

trimmed to remove damaged parts or dressing defects,

or condemned if unfit for food.

0018 Workers harvest, clean, and save the giblets (heart,

liver, and gizzard). They clean the gizzard by splitting

it, washing away the contents, peeling off the hard

lining, and washing. They discard the inedible vis-

cera, and remove the lungs with a special tool or

vacuum lung gun.

0019 As one of the last operations, the head is cut or

pulled off, and the esophagus and crop are removed

from the front of the carcass. Finally, the skinless neck

is cut off, washed, and retained for packing. Following

evisceration, the birds must be washed inside and out

before chilling.

0020 It is possible to perform some of the slaughter

and evisceration operations mechanically, but the

variability in turkey carcass sizes presents unique

problems. Fully automated equipment for turkey pro-

cessing is still being developed.

Chilling

0021 Most processors chill poultry meat in cold water or

water and ice, but they use air chilling extensively in

Europe, where carcasses are more often soft-scalded

and sold fresh. The most-used chillers in the USA

drop the birds from the evisceration line into a pre-

chiller which also serves as a very effective washer.

The agitated water has a temperature of less than



C. The birds travel to a second chiller with a

water temperature of less than 2



C. Inspectors care-

fully monitor chiller water overflow, and carcass exit

temperature and water uptake.

0022 After chilling, graders evaluate the carcasses

according to conformation, fleshing, fat covering,

and defects such as pinfeathers and exposed flesh.

(See Meat: Preservation.)

Packaging

0023 In some plants, turkey carcasses move directly to a

cut-up or deboning line. If turkeys are sold as whole

carcasses, workers place a giblet packet in the crop

cavity and a neck in the body cavity. Processors truss

the legs into the bar cut, or use a metal or plastic hock

lock. These turkeys will probably be frozen, in which

case they are placed in an oxygen-impermeable,

shrink-film bag. After the air is evacuated, the bags

are clipped shut and passed through a hot-water

shrink tunnel prior to freezing.

0024The freezing process is very rapid, with the first

step being a brine or blast freezer to set the carcass

surface color. Final freezing and storage occur in a

holding freezer, where the birds can be stored for

relatively long periods of time until they are moved

into market channels.

Food Uses and Products

0025About 75% of the turkeys produced in the USA are

cut up or further processed. In some countries, such as

Israel, France, and Italy, the proportion of cut-up or

further-processed turkey is 90% or more. However,

whole birds are still popular at holiday times. Some of

the whole carcasses are injected with various flavored

solutions to create a self-basting, juicier carcass when

roasted.

Deboning

0026Deboning of chilled turkey carcasses usually occurs as

they hang from special shackles on a slow-moving

line, or sit on deboning cones which may be static or

moving. Precise cuts are made to remove parts, breast

meat, thigh meat, and trimmings from the skeleton.

The drumsticks (and also the thighs) are often

deboned on automated machines, whereby the drum-

stick bone may be pushed lengthwise out of the meat;

thigh pieces may be compressed in a specially designed

mold, squeezing the meat away from the bone. More

deboning automation will occur in the near future.

0027After removal of intact muscles using knives or

semiautomated procedures, the remaining frames,

necks, and backs are usually mechanically deboned.

One system uses an auger principle, pressing the meat

and bone against a perforated cylinder screen or

microgrooved cylinder. The alternative system is a

hydraulic-press-type batch design which squeezes

the meat through a series of stationary filter rings.

Depending on the incoming meat materials (meat-to-

bone ratio), screen perforation size, and machine ad-

justments, the mechanically deboned meat can be a

very fine pure

e or have a particle size of 5 mm, which

is ideal for some sausages.

Further Processing

0028Hand- and mechanically deboned meats are useful

in many further-processed products. The term ‘fur-

ther processing’ encompasses procedures such as

deboning, size reduction, injection, tumbling, massa-

ging, reforming, and emulsifying. The principles of

POULTRY/Turkey 4691

water-holding, protein extraction, protein gelation,

and meat binding are very important in making fur-

ther-processed products. Other processes, such as

battering, breading, cooking, and freezing, may take

place. Further processing also refers to whole car-

casses that are basted, marinated, or smoked.

0029 The types of products now available are increasing,

ranging from cut-up portions to reformed roasts,-

breasts, rolls, steaks, hams, burgers, frankfurters,

bolognas, coarse-ground sausages, salamis and

bacons. More recently, ready-prepared meals have

utilized an increasing amount of turkey meat. (See

Meat: Sausages and Comminuted Products.)

0030 Consumers with changing careers and households

are the driving force behind trends in the consump-

tion of poultry products. Smaller families often lack

time but can afford the convenience of further-

processed poultry. Diet and health, microwave

ovens, and an aging population are important factors

in new product development. Ethnic foods, especially

Italian, Mexican, and Chinese, are popular in the

USA. Different flavors and marinades, such as

honey and barbecue, are well liked in turkey prod-

ucts. Smaller portions, less fat, less salt, and low

cholesterol are in vogue. Poultry appetizers, finger

foods, sliced luncheon meats, and center-of-the-plate,

cooked, vacuum-packaged, chilled boneless breasts

are very popular. New turkey products could soon

include sous-vide (vacuum-sealed, cooked, refriger-

ated, ready-to-heat) entre

es, or possibly surimi

(minced washed gelled protein, usually from fish)

seafood-style favorites.

Microbiological Concerns

0031 Turkey meat quality is highest immediately after pro-

cessing. The maintenance of acceptable quality

depends on initial microbial levels and measures

taken to minimize organism growth and prevent fur-

ther contamination. The two major concerns are

spoilage organisms which cause odors or off-flavors,

and pathogenic organisms which may, under faulty

handling such as undercooking or temperature abuse,

lead to a health hazard. The cutting, deboning, hand-

ling, mixing, and packaging of turkey meat also in-

crease possible microbial contamination and growth.

(See Spoilage: Bacterial Spoilage.)

0032 Although turkey and turkey products are refriger-

ated or frozen for shelf-life extension, spoilage can

occasionally occur as a result of the growth and meta-

bolic activities of specific types of bacteria. Psychro-

philes, such as Pseudomonas, can grow at refrigerator

temperatures and cause problems. Turkey has reached

spoilage conditions when an off-odor becomes appar-

ent (10

cells per cm

) or when slime formation

occurs (10

organisms per cm

). It is important to

maintain refrigeration temperatures at 0–4



C to min-

imize microbial growth in turkey and turkey products.

0033Food pathogens are more serious than spoilage

organisms because the food product may not look

or smell spoiled. Some of the pathogens of concern

in turkey are Salmonella, Staphylococcus, Campylo-

bacter, Listeria, and coliforms. Recently, Salmonella

has been a major worry for consumers, and turkey

carcasses do harbor the organism. Surveys in the USA

indicate that in food-borne salmonellosis outbreaks

only 4.5% are caused by turkey. To prevent food-

borne illness from poultry, it must be kept refriger-

ated and cooked properly, and cross-contamination

or postcooking contamination from unclean utensils

or equipment must be avoided. (See Campylobacter:

Campylobacteriosis; Listeria: Listeriosis; Staphylo-

coccus: Food Poisoning.)

0034Bacteria can come from many sources. At the pro-

cessing plant, bacteria arrive on the feet and feathers

of the birds; they are present in the intestinal contents,

and can also come from the workers and the environ-

ment (air and water supplies). Bacterial problems can

be minimized by following good production and

manufacturing practices such as feeding clean feed

and keeping the litter dry at the production site,

using clean hauling equipment, filtering incoming

air at the processing plant, monitoring the water

supply, eviscerating carefully, chlorinating chiller

water, insisting on good worker hygiene, and using

an approved plant clean-up and sanitation program.

Utilization of Waste Products

0035Poultry processing results in large amounts of highly

polluting waste waters, semisolids, and solids, which

must be separated and treated before being dis-

charged into the environment. Where practical, the

use of waste products for livestock food or fertilizer

reduces the overall load for disposal. Rendered

poultry byproducts as an animal feed ingredient can

provide 50–60% protein. Feather meal and dried

blood also have value as a feedstuff. Such products

must be carefully processed before being recycled as

animal feed, to avoid microbial contamination.

0036The types of waste and byproducts differ at varying

stages of processing. Manure, feathers, blood, vis-

cera, flesh debris, grease, and cleaning water are

examples of the pollutants to be treated and either

used or discarded.

0037The methods of disposal are to a public sewer, or

treatment on-site followed by disposal to a water

course or to fields. Preliminary treatment of turkey-

processing wastes using a coarse-solids screen

separator as well as a fatty-matter trap, or chemical

4692 POULTRY/Turkey

flocculation combined with a dissolved air flotation

system, will significantly reduce the pollution poten-

tial of the effluent before discharge or further bio-

logical treatment. Based on the strength of the

effluent, a secondary biological treatment uses a

mixed culture of microorganisms for anaerobic diges-

tion or aerobic treatment. The cheapest and most

cost-effective options for the disposal of stabilized

processing sludges arising from the biological treat-

ment of poultry processing effluents are to spread

them on the land or to discharge them at land-fill

sites. (See Effluents from Food Processing: Compos-

ition and Analysis; Disposal of Waste Water.)

Nutritional Significance

0038 Table 1 shows the nutrient composition of selected

raw and cooked turkey meats, and Table 2 lists

the composition of several further-processed turkey

products.

0039 Turkey and its products have a favorable reputa-

tion as nourishing and healthy foods. The compos-

ition of raw turkey meat depends on factors such as

diet, age, sex, and growth environment. Processed

product nutrition (Table 2) is a result of incoming

meat and nonmeat ingredients as well as cooking

processes and formula variations by different manu-

facturers. Salt and fat can vary markedly, depending

on whether salt was needed for protein extraction and

binding, or whether skin (with adhered fat) was

added for juiciness and flavor.

0040Consumers recognize turkey as a good protein

source. Turkey meat is easily digestible, contains all

the essential amino acids, and is a good source of the

B vitamins and iron. (See Amino Acids: Metabolism;

Vitamins: Overview.)

0041Turkey has a relatively low fat content, and the fat

is only about 30% saturated. Because the fat is highly

unsaturated (more than beef and pork), it is a softer

type of fat and prone to oxidation. As turkeys grow,

they deposit more fat under the skin. The fat content

is higher in dark meat, and protein content is greater

in light meat. Moisture and some fat are lost during

heating, and protein is concentrated in cooked turkey.

0042Turkey products are somewhat similar to other

processed meat products in protein content but are

higher in moisture and lower in fat and energy. This

favorable nutritional profile for turkey is one of

the major reasons for its increasing popularity. (See

Protein: Food Sources.)

tbl0001 Table 1 Proximate analysis of turkey (per 100 g edible portion, wet-weight basis)

Nutrient Breast withskin (raw) Breast withskin (roasted) Legwith skin (raw) Legwith skin (roasted) Light meatonly (raw)

Water (g) 70.05 63.22 72.69 61.19 73.82

Protein (g) 21.89 28.71 19.54 27.87 23.56

Energy (kJ) 659 794 605 874 483

Lipids

Total (g) 7.02 7.41 6.72 9.82 1.56

Saturated (g) 1.91 2.10 2.06 3.06 0.50

Unsaturated (g) 4.32 4.25 3.89 5.59 0.69

Cholesterol (mg) 65 74 71 85 60

Ash (g) 0.91 1.03 0.89 0.99 1.00

Sodium (mg) 59 63 74 77 63

Reproduced from Posati LP (1979) Composition of Foods. Poultry Products, Raw, Processed, Prepared. Agriculture Handbook 8-5. Washington, DC: Science

and Education Administration, US Department of Agriculture.

tbl0002 Table 2 Proximate analysis of selected turkey products (per 100 g edible portion, wet-weight basis)

Nutrient Ham Roll (light) Salami Frankfurter Loaf (breast)

Water (g) 71.38 71.55 65.86 62.99 71.85

Protein (g) 18.93 18.70 16.37 14.28 22.50

Energy (kJ) 538 617 823 949 462

Lipids

Total (g) 5.08 7.22 13.80 17.70 1.58

Saturated (g) 1.70 2.02 0.48

Unsaturated (g) 2.67 4.24 0.73

Cholesterol (mg) 43 82 107 41

Ash (g) 4.23 2.00 3.42 3.53 4.18

Sodium (mg) 996 489 1004 1426 1431

Reproduced from Posati LP (1979) Composition of Foods. Poultry Products, Raw, Processed, Prepared. Agriculture Handbook 8-5. Washington, DC: Science

and Education Administration, US Department of Agriculture.

POULTRY/Turkey 4693

See also: Amino Acids: Metabolism; Campylobacter:

Campylobacteriosis; Effluents from Food Processing:

Disposal of Waste Water; Composition and Analysis;

Listeria: Listeriosis; Meat: Slaughter; Preservation;

Sausages and Comminuted Products; Protein: Food

Sources; Spoilage: Bacterial Spoilage; Staphylococcus:

Food Poisoning; Vitamins: Overview