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and the presence of parental obesity increase the

likelihood that obesity will persist in adulthood. A

recent Washington state study tracked 850 infants

over 21–29 years and found that among obese 6

years olds, about 50% remained obese. By the age

of 10–14 years, 80% of obese children with at least

one obese parent remained obese.

Global Trends in Obesity

0019 Both childhood and adult obesity are becoming

global concerns. Other industrialized countries such

as England, Singapore, Japan, Canada, and Australia

are also experiencing increasing rates of obesity in

both adults and children. Similar to data from the

US, women from other countries tend to have higher

rates of obesity compared with men, although men

may have higher rates of overweight. The WHO

reports that the prevalence of obesity is also increas-

ing in countries undergoing economic transition and

in developing countries where obesity coexists with

undernutrition.

Risk Factors for Obesity in Adults and

Children

0020 It is widely accepted that overweight and obesity are

multidetermined chronic problems resulting from

complex interactions between genes and environments

characterized by energy imbalance due to sedentary

lifestyles and ready access to a wide variety of foods.

Research suggests obesity runs in families and that

some individuals are more vulnerable than others to

gaining weight and becoming obese. Researchers also

agree that there is no single gene that causes obesity,

but that multiple genes and gene mutations associated

with weight gain are involved. Various mechanisms

through which genetic susceptibility to weight gain

have been proposed including a low resting metabolic

rate, low level of lipid oxidation rate, low fat-free

mass, and poor appetite control. Although genetic

research is a promising approach for understanding

the development of obesity and identifying those at

risk for obesity, it should be noted that the rapid in-

creases in rates of obesity and overweight that have

been observed have occurred over too brief a time

period for there to have been significant genetic

changes in the population. Therefore, the following

sections briefly review environmental factors associ-

ated with the obesity epidemic.

Environmental Influences: Dietary Intake

0021 Increased population levels of energy intake is a likely

contributor to the epidemic of obesity. However,

research on trends in energy intake over the time

period in which the prevalence of obesity has in-

creased has not consistently supported this hypoth-

esis. Data from national surveys show a decrease in

energy intake over time, whereas, nutrient intake data

from NHANES III show an increase in energy intake

over time. A recent review of ecological data

regarding the amounts and types of food available

in the USA during the past two decades provides

interesting data that may shed light on some of the

discrepancies found in previous survey data. Specific-

ally, although the availability and purchasing of re-

duced fat and reduced energy foods has increased

over the past few decades, people are eating more

meals away from home, eating larger portions, and

consuming more convenience foods. These behaviors

are more conducive to higher energy intakes and may

be contributing to the increased prevalence of obesity.

Environmental Influences: Physical

Activity

0022Low levels of energy expenditure are increasingly

recognized as important contributors to obesity and

related health conditions. An abundance of cross-

sectional research shows that heavier individuals are

less active than lighter individuals, and prospective

research indicates that changes in physical activity

level are associated with changes in body weight in

the direction predicted by the energy balance equa-

tion. The past century has produced dramatic changes

in physical activity patterns in the USA. Machines and

labor-saving devices have become so commonplace

that the energy expenditure now required for daily

life is a fraction of what it was a generation or two

ago. Voluntary or leisure-time physical activity has

thus assumed central importance in meeting physical-

activity requirements. Unfortunately, voluntary phys-

ical activity is not very popular. Less than 25% of all

adults, adolescents, and children report that they

engage in regular physical activity (i.e., a minimum

of 30 min of moderate to vigorous activity on most

days of the week), the activity level most recently

recommended by health experts. The prevalence of

regular physical activity also varies according to

demographic characteristics. Decreases in physical

activity are observed during adolescence, with

the decline particularly pronounced among girls.

Women are less physically active than men, older

adults are less active than younger adults, and African

American and Hispanic adults are less active than

whites. A lower socio-economic status is also associ-

ated with lower levels of physical activity.

0023Although low levels of leisure-time physical activ-

ity likely contribute to the epidemic of obesity, it is

4244 OBESITY/Epidemiology

noteworthy that among adults, leisure-time activity

has remained stable or increased since the mid-1980s,

the time period during which the prevalence of

obesity increased. Given this paradoxical finding, it

is likely that increases in sedentary activities such as

television watching and computer use and decreases

in lifestyle, household, and occupational activity that

have been less carefully measured have contributed to

reductions in overall energy expenditure at the popu-

lation level. Data from the Americans’ Use of Time

study show that the amount of free time spent watch-

ing television increased from about 4 h per week in

1965 to about 15 h in 1985. Documenting the preva-

lence of sedentary behavior among children and

adults and targeting the reduction of sedentary activ-

ity as a health-behavior goal have received consider-

able attention in recent years.

Future Directions

0024 Understanding and addressing the epidemic of

obesity has become a global public-health priority.

A recent 1997 WHO report on obesity, entitled

‘Obesity: Preventing and Managing the global Epi-

demic,’ noted that overweight and obesity represent a

rapidly growing threat to the health of populations

world-wide. Both children and adults in developing

and developed countries are affected. The report con-

cluded that the spectrum of problems seen across the

world is of such magnitude that obesity should be

regarded as the principally neglected public-health

problem.

0025 The recently released goals of Healthy People 2010

are to reduce the prevalence of obesity among adults

from 23 to 15% and to reduce the prevalence of

obesity among children and adolescents from 11 to

5%. The etiology of obesity is complex and encom-

passes a wide variety of social, behavioral, cultural,

environmental, physiological, and genetic factors. To

achieve these ambitious goals, considerable effort

must be focused on helping individuals at the popula-

tion level modify their diets and increase their

physical activity levels, key behaviors involved in

the regulation of body weight. A challenge to

public-health professionals is to develop educational

and environmental interventions that support diet

and exercise patterns associated with a healthy body

weight. Prevention of obesity should begin early in

life and involve the development and maintenance of

healthy eating and physical activity patterns. These

patterns need to be reinforced at home, in schools,

and throughout the community. Communities,

government, health organizations, the media, and

the food and health industry must form alliances if

we are to combat obesity.

0026A coherent and standard international system for

classifying overweight and obesity in children and

adults is also needed. The WHO and US agencies

recommend using BMI for adults, with BMI 25

denoting ‘overweight’ and BMI > 30 denoting

‘obesity.’ Criteria and methods for assessing and

documenting obesity in children and adolescents

need to be similarly developed. A common inter-

national standard would allow meaningful compari-

sons of obesity within and across populations and

document obesity trends over time.

See also: Adolescents; Children: Nutritional Problems;

Nutritional Assessment: Anthropometry and Clinical

Examination; Obesity: Etiology and Diagnosis

Further Reading

Allison DB, Fontaine KR, Manson JE, Stevens J and Van-

Itallie TB (1999) Annual deaths attributable to obesity

in the United States. Journal of the American Medical

Association 282(16): 1530–1538.

Clinical Guideline on the Identification, Evaluation, and

Treatment of Overweight and Obesity in Adults. The

Evidence Report (1999) National Institutes of Health.

National Heart, Lung, and Blood Institute.

Flegal KM, Carroll MD, Kuczmarski RJ and Johnson CL

(1998) Overweight and obesity in the United States:

prevalence and trends, 1960–1994. International Jour-

nal of Obesity 22: 39–47.

Harnack L, Jeffery R and Boutelle K (in press) Temporal

trends in energy intake in the U.S.: an ecological perspec-

tive. American Journal of Clinical Nutrition.

Kuczmarski RJ, Flegal KM, Campbell SM and Johnson CL

(1994) Increasing prevalence of overweight among US

adults. Journal of the American Medical Association

272(3): 205–211.

Mokdad AH, Serdula MK, Dietz et al. (1999) The spread of

the obesity epidemic in the United States, 1991–1998.

Journal of the American Medical Association 282(16):

1519–1522.

Must A, Spadano J, Coakley EH, Field AE, Colditz G and

Foryx WD (1999) The disease burden associated with

overweight and obesity. Journal of the American Med-

ical Association 282(16): 1523–1529.

Obesity: Preventing and Managing the Global Epidemic.

Report of a WHO Consultation on Obesity.3–5 June

1997. Division of noncommunicable diseases. Geneva:

WHO.

Strauss R (1999) Childhood obesity. Current Problems in

Pediatrics 29: 5–29.

Troiano RP and Flegal KM (1998) Overweight children and

adolescents: description, epidemiology, and demograph-

ics. Pediatrics 101(supplement 3): 497–504.

US Department of Health and Human Services (1996)

Physical Activity and Health: A Report of the Surgeon

General. Atlanta, GA: US Department of Health and

Human Services, Centers for Disease Control and

OBESITY/Epidemiology 4245

Prevention, National Center for Chronic Disease Pre-

vention and Health Promotion.

Williamson DF (1991) Epidemiologic analysis of weight

gain in U.S. adults. Nutrition 7(4): 285–286.

Williamson DF, Kahn HK, Remington PL and Anda RF

(1990) The 10-year incidence of overweight and major

weight gain in U.S. adults. Archives of Internal Medicine

150: 665–672.

Odors See Sensory Evaluation: Sensory Characteristics of Human Foods; Food Acceptability and Sensory

Evaluation; Practical Considerations; Sensory Difference Testing; Sensory Rating and Scoring Methods;

Descriptive Analysis; Appearance; Texture; Aroma; Taste

OFFAL

Types of Offal

W F Spooncer, CSIRO, University of Western Sydney,

Richmond, NSW, Australia

This article is reproduced from Encyclopaedia of Food Science,

Introduction

0001 Offals are all the noncarcass parts of slaughtered

animals with the exception of hide and skin. Most

offals have the potential to be used as human food but

this potential can only be realized if the offals are

collected hygienically, inspected, and passed fit for

human consumption, then cleaned and prepared

in an appropriate manner. Offals which are not

collected for human use, either because there is no

demand for them, or because they are diseased or

contaminated, are inedible offals. Inedible offals are

either destroyed by burning or burying, rendered

to produce tallow and meat meal or, if suitable, used

as pet food. (See Meat: Slaughter.)

Definition of Offals

0002 Because of the variety of different types of offals, both

edible and inedible, some attempts have been made to

group offals together in categories. Many texts refer

to offal as being derived from the ‘off fall’ from

carcass preparation. Some of this ‘off fall’ may be

attractive as edible product while some of it may not

be edible at all. To avoid the connotation that offals

include unattractive and inedible material, the terms

‘variety meats’ and ‘fancy meats’ have been intro-

duced as categories of offals which are edible and

prepared and consumed in a recognizable form.

Variety meats and fancy meats are items such as

heart, tongue, kidney, sweetbread, liver, brain, tail,

and tripe. In the USA, where the term variety meat is

common, products which are not consumed in a

recognizable form but could be used in processed

meats are referred to as offal meat. Examples of

offal meat are lungs, spleen, udders, and head meat.

In this case the word ‘offal’ is reserved for inedible

material.

0003Other ways in which offals are categorized include

the distinction between white and red offals, and

between organ offal and muscle offal.

0004The categories of white and red offal are used to

distinguish stomach and intestinal offals from all

other offals. This distinction is made because white

offals require careful cleaning and preparation to

remove intestinal and stomach contents before they

can be used as edible material. Intestinal offal should

be cleaned in an area separated from the preparation

of other offals and carcass meat. Separate facilities

for handling white and red offals minimize the chance

of red offal being contaminated by intestinal

contents.

0005The distinction between offals which are mainly

organ tissue and those which are muscular tissue is

made because of the difference in the potential keep-

ing quality of the two types of offals. Organ offals,

such as liver, kidney, lungs, spleen, and brain, are not

as stable as muscular offals, such as tail, tongue, and

diaphragm. In chilled storage, physiological activity

in organ tissues can result in deterioration of the

flavor and texture. (See Meat: Preservation.)

Specific Offals

0006Table 1 lists the items of offal available from slaugh-

tered animals, alternative names, and possible

4246 OFFAL/Types of Offal

categorization of the offals. Table 2 lists typical

weights of offals from different carcass types. (See

Beef; Pork; Poultry: Chicken; Ducks and Geese;

Turkey.)

0007 According to American surveys, the more popular

offals are liver, pigs’ feet, oxtail, heart, tongue, pork

maw (stomach), brains, sweetbread, tripe, and

kidney. These offal items are described below. Other

offals listed in Table 1 do not appeal to western tastes

but are popular in other markets, particularly in

Asian countries.

Liver

0008 Liver is the largest organ in meat-producing species.

Its color varies from light red to dark red brown and

even black in old animals. The liver is attached by

ligament to the anterior abdominal wall and to the

stomach by the lesser omentum. During evisceration

these attachments are torn or cut, and the liver is

removed attached by ligament to the diaphragm and

the rest of the pluck (heart, liver, lung, and dia-

phragm). The liver is separated from the pluck by

cutting through the attachment to the diaphragm.

The gallbladder and duct are then pulled or cut off

the liver.

0009Liver is composed of specialized liver cells with a

network of blood vessels and epithelia-lined ducts

between the cells. The cells are held together by a

network of connective tissue.

0010The texture and flavor of liver are affected by

species and animal age. Livers from young animals

are lighter in color, have more delicate flavor, and are

more tender than those from older animals. Lamb

and calf liver, and liver from young beef are more

suitable for table dishes. Liver from mutton, older

bulls, and cows are used in manufactured or pro-

cessed meats. Pig livers have a strong flavor which is

tbl0001 Table 1 Summary of offal types

Offaltype Alternative name Category of offal

Variety meat Red or white offal

Organ or glandular offal

Liver

;

Lamb’s fry [ Red

Heart Pluck [ Red

Lung Lights Red

Brain [ Red

Thymus Sweetbread,

heartbread,

neckbread

[ Red

Kidney [ Red

Pancreas Gutbread Red

Spleen Melt Red

Stomach Pig’s maw [ White

Rumen Blanket tripe [ White

Reticulum Honeycomb tripe [ White

Omasum Bible White

Abomasum Reed (or vell

in calves)

White

Testes Fries Red

Udder Red

Uterus White

Muscular offals

Head meat Red

Cheek Red

Tail Oxtail [ Red

Diaphragm Skirt [ Red

Tongue (also considered

glandular)

[ Red

Esophagus Weasand Red

Others

Head Red

Feet Red

Intestines Chitterlings (pig only) White

Ear Red

Bone marrow Red

OFFAL/Types of Offal 4247

appreciated in Asian countries, but in the west pig

livers are used in processed meats rather than in table

dishes.

0011 To distinguish between the classes of bovine liver,

they may be graded by weight. Livers in the range

1–3 kg are classed as calf livers. Larger livers from

beef or ox may be graded into weight ranges of

3–4 kg, 4–5.5 kg, and over 5.5 kg. Ovine livers are

not strictly graded but lamb liver should not exceed

700 g.

Heart

0012 Hearts can be collected and trimmed in several styles.

Whole hearts are removed from the pericardium

and separated from the lungs and remainder of the

pluck by cutting through the aorta and pulmonary

vein. Whole hearts may be trimmed by cutting off

the auricles along with the ossa cordis bones, aorta,

and pulmonary vein. Even if the auricles remain in

place, whole hearts are trimmed to remove remnants

of the aorta, pulmonary vein, and the fibrous rings of

the ossa cordis. Trimmed hearts comprise ventricles

with associated fat, arteries, and veins, and may or

may not include the auricles. They should be well

washed to remove blood clots. Large hearts may be

split open by cutting through the ventricle wall from

the base to the apex.

0013 The thick walls of the ventricles are composed of

cardiac muscle, which is tough even in young

animals. Cardiac muscle is supported by a network

of connective tissue, which also contributes to the

toughness of heart meat from older animals.

Tongue

0014Full tongues consist of the blade of the tongue with

the roots attached, including the hyoid bones except

the stylohyoid, the larynx, three tracheal rings, lymph

nodes, salivary glands, and associated muscle and

connective tissue. Short-cut tongues are a more

common style of trim and are derived from full

tongues by removing the larynx and roots by cutting

behind the hyoid bones. Other trims of tongue are

prepared with the hyoid bones removed.

0015The tongue blade is a core of skeletal muscle and

connective tissue covered with an epithelial mucous

membrane.

Brain

0016Brains include the cerebrum, cerebellum, and a

portion of spinal cord. They are collected after

opening the skull by splitting the occipital and maxil-

lary bones. The brain is removed from the skull

cavity, leaving the outer skin (the dura mater) in the

skull but with a fine membrane (the pia mater and

arachnoid meninges) covering the brain tissue.

This membrane can be removed when the brain is

cooked.

0017Brain tissue is not supported by a network of con-

nective tissue and, consequently, has a soft, delicate

texture.

Sweetbread

0018Sweetbread is the thymus gland and is only available

from young animals. As animals mature, the gland

tbl0002 Table 2 Typical weight of offals

Ovine Porcine Bovine

Lamb (g) Mutton (g) Porker (g) Baconer (g) Veal (kg) Beef (kg)

Liver 300 – 600 650 – 720 700 – 1200 1200 – 2000 0.75 – 3.0 2.5 – 8.0

Heart 90 – 150 180 – 215 150 – 250 200 – 300 0.25 – 1.0 0.8 – 2.0

Lung 200 – 350 400 – 500 500 – 850 750 – 1100 0.65 – 1.5 1.5 – 6.0

Brain 75 – 110 100 – 130 NA NA 0.15 – 0.23 0.23 – 0.35

Thymus 50 – 100 NA NA NA 0.03 – 0.125 NA

Spleen 40 – 65 70 – 110 70 – 130 100 – 150 0.1 – 0.6 0.6 – 1.0

Stomach

Maw NA NA 450 – 600 500 – 800 NA NA

Rumen and reticulum 250 – 500 500 – 800 NA NA 0.5 – 1.5 2.0 – 10.0

Omasum 30 – 400 400 – 500 NA NA 0.2 – 1.0 1.0 – 5.0

Abomasum 80 – 140 150 – 200 NA NA 0.35 – 0.75 0.7 – 3.0

Uterus NA NA 100 – 250 200 – 600 NA NA

Cheek NA NA 1000 – 1800 1500 – 2000 0.3 – 0.7 0.7 – 1.2

Tail NA NA NA NA 0.2 – 0.6 0.55 – 1.2

Diaphragm NA NA 170 – 250 200 – 280 0.2 – 0.6 0.55 – 1.1

Tongue (short-cut) 50 – 100 80 – 150 120 – 200 150 – 220 0.15 – 0.7 0.7 – 1.6

Head NA NA 2000 – 3000 2800 – 3800 3.0 – 5.5 NA

Feet NA NA 230 – 280 300 – 400 0.2 – 0.4 NA

Ear NA NA 100 – 300 100 – 500 NA NA

NA, not available.

4248 OFFAL/Types of Offal

degenerates into a mass of connective tissue and fat.

The sweetbread is collected in two separate portions,

although it is a single gland. The main portion, also

called neckbread, is found in the neck, either side of the

trachea. The other portion is in the chest cavity, close to

the heart, and may be called heartbread. After

collection, fat and connective tissue is trimmed off

the gland.

0019 The thymus gland consists mainly of lymphocytes

and is covered by a capsule of connective tissue. The

capsule penetrates the gland and divides it into

lobules. The texture of sweetbread is delicate but

may be tough if sweetbreads are collected from

older animals in which the thymus gland has started

to degenerate. Sweetbreads are soaked in water to

remove blood, blanched to firm the texture, and

skinned to remove the capsule before they are

prepared for the table.

Kidney

0020 Kidneys are contained in a capsule of fat and remain

in the carcass after evisceration. The common way to

handle kidneys is to remove them from the capsule for

inspection, trim off the ureter and renal blood vessels

close to their entry to the kidney and, for beef

kidneys, cut out the core of fat and connective tissue

from the renal hilus.

0021 Kidneys are made up of renal tubules and small

veins and arteries. The structural components are

the endothelial and epithelial cells of these vessels,

and a network of connective tissue. There is a fibrous

capsule of connective tissue around the kidney which

is usually removed before kidneys are cooked.

0022 Kidneys from sheep and pigs have the characteristic

bean shape. Beef and calf kidneys are divided into

lobules.

Pigs’ Feet

0023 Forefeet are collected from pig carcasses by cutting

the foreleg between the carpal and metacarpal bones.

Similarly, hindfeet are collected by cutting between

the tarsal and metatarsal bones. Pigs’ feet comprise

the bones, tendons, skeletal muscle, connective tissue,

fat and skin of the trotters, but toenails and all hair

should be removed.

0024 The edible part of pigs’ feet is fat, muscle, and

connective tissue. Prolonged moist cooking of the feet

will soften and at least partially gelatinize the collage-

nous connective tissue and make the flesh tender.

Oxtail

0025 Tails are collected from beef and veal carcasses by

cutting off the tail at the sacrococcygeal junction.

Tails consist of the coccygeal (tail) vertebrae with

associated skeletal muscle, connective tissue, and

fat. The last two or three vertebrae may be removed,

and some or all of the subcutaneous fat at the anterior

end of the tail may be trimmed off.

Tripe

0026Cattle and sheep stomachs have four compartments,

all of which can be used to make tripe. Tripe from the

rumen and reticulum is the most common. Rumen

tripe is known as blanket tripe and reticulum tripe

is known as the honeycomb. The internal surface

of the rumen has densely packed papillae, while the

reticulum has ridges in the shape of a honeycomb

structure. In addition, there are thickened folds in

the rumen wall. These folds contain a core of smooth

muscle and are not covered by papillae. The fold

can be trimmed out of the rumen to produce pillae

tripe, known commercially as pillar or mountain

chain.

0027The third compartment of the ruminant stomach is

the omasum. The internal wall is in the form of deep,

thin folds like the pages of a book. This appearance

accounts for the popular name for the omasum,

which is ‘bible.’ Although the omasum has a delicate

flavor and texture, it is not commonly used as tripe

because of the difficulty of cleaning the stomach con-

tents from between the folds. The fourth part of the

ruminant stomach is the abomasum, sometimes

called the reed.

0028The four parts of the stomach are collected in one

piece and the omental fat (caul fat) and spleen are

removed. The neck of the omasum is cut to separate

the rumen and reticulum from the omasum and abo-

masum. The rumen is cut open and the contents of the

rumen and reticulum washed out. The rumen and

reticulum are then trimmed into the different tripes,

and external fat is trimmed off. Mountain chain tripe

does not receive further processing, but blanket and

honeycomb tripes may be further cleaned, scalded,

and bleached with hydrogen peroxide.

0029The walls of ruminant stomachs are composed of

smooth muscle and connective tissue. The papillae in

the rumen are composed of collagen and elastin fibers

covered with cornified epithelia, while the ridges and

folds in the reticulum and omasum contain smooth

muscle as well as connective tissue. There are small,

cornified papillae on the folds of the omasum, and the

surfaces of the folds are covered by a keratinized

mucous membrane. The abomasum has a thick

epithelial lining.

0030Tripes are generally tough because of the high

connective tissue content. They contain about 35 g

of collagen per 100 g of protein. They require

prolonged, moist cooking to tenderize them. Bleached

OFFAL/Types of Offal 4249

tripe is treated with caustic soda and has a pH of

about 7–9, which increases the water-holding cap-

acity and helps to tenderize the tripe.

Maw

0031 Pig’s stomach or maw is a similar organ to the rumin-

ant abomasum. The maw is separated from the rest of

the viscera by pulling off the omental fat and spleen

from their attachments to the stomach and cutting

through the esophagus and duodenum. The maw is

then split open and the contents washed out. After

cleaning the maw, it is usually scalded in water at

about 90



C to remove the mucous membrane lining.

0032 In common with the abomasum, the maw is com-

posed of a wall of smooth muscle and connective

tissue, with an inner lining of thick epithelia and

mucous membrane.

Offal for Human Use

0033 Offal consumption varies from about 1.7 kg per

person per year in Canada to about 16 kg per person

per year in Ireland. Table 3 shows per capita con-

sumption of offal in western countries.

0034 As shown in Table 1, almost all noncarcass parts

can be used as food after the carcass and offal have

been inspected and found fit for human consumption.

(Exceptions are uteri from pregnant animals, and

fetuses.) After collection, offals are trimmed and

washed to remove contamination by blood, saliva,

mucus, and ingesta. They may be distributed frozen,

chilled, or vacuum-packed and chilled. Frozen

offals held at 18



C have a useful shelf-life of 6

months; chilled offals have a shelf-life of 2–3 days;

and vacuum-packed tail, tongue, skirt, heart, kidney,

and liver have a shelf-life of at least 3 weeks at 1



0035Offals are consumed both as table dishes and in

manufactured meat products such as sausages and

. There are many options for preparing and

cooking offals, commensurate with the wide ranges

of offal types. Some offals require initial treatment

such as soaking and precooking. Brains, sweetbreads,

and testicles are soaked in cold water to remove blood

pigment and improve color. They are then blanched

by brief immersion in hot water to firm the texture

before they are cooked by other methods. Liver and

kidney, particularly from older animals, may also

be soaked to leach out the strong flavor associated

with these offals. Stomachs and intestines are pre-

cooked by prolonged immersion in hot water to

remove the mucosal membrane, and soften connect-

ive tissues. Tongues are also precooked, after which

the thick skin of epithelia on the tongue blade can be

peeled off. (See Meat: Sausages and Comminuted

Products.)

0036Regulations may restrict the way in which offals

are used in manufactured and comminuted meat

products. In the EC and Australia, offals are con-

sidered to be meat but are distinguished from meat

of skeletal muscle origin by using terms such as car-

cass meat and meat flesh, which exclude offal meat.

In the USA, heart and tongue are considered to be

meat, and other offals have the status of meat by

products. The greatest restrictions on the use of offals

is in uncooked meat products such as fresh sausages.

0037In Australia, no offals are permitted in fresh saus-

age and in the USA only tongue and heart can be used

in fresh sausage. In the UK the designated list of

permitted offals which can be used in uncooked prod-

ucts includes heart, kidney, liver, and tongue. In

general, cooked meat products may contain offals.

The Codex Alimentarius Commission has standards

which restrict the use of offals in specific products. In

summary, these standards are as follows:

0038Canned corned beef. Heart meat is the only offal

permitted.

0039Luncheon meat. Luncheon meat with binder may

contain offals, with the exception of lungs that

have been collected from animals scalded by

immersion in water. Only heart and tongue are

permitted in luncheon meat without binder.

0040Cooked cured chopped meat. Only heart and

tongue are permitted in products which do not

contain binder. Offals (except udders, lungs, and

tbl0003 Table 3 Per capita consumption of offals by countries

Consumption (kgper

headperyear)

Australia 4.7

Austria 4.5

Belgium and Luxembourg combined 8.0

Canada 1.7

Denmark 7.0

Republic of Ireland 16.7

Finland 8.1

France 6.6

Greece 6.0

Italy 3.8

Japan 2.5

The Netherlands 2.6

New Zealand 6.0

Norway 2.7

Portugal 5.0

Spain 4.0

Sweden 2.5

Switzerland 5.9

Turkey 2.1

UK 4.3

USA 4.1

Germany 5.7

Yugoslavia 2.9

4250 OFFAL/Types of Offal

organs and glands from the genital system) may be

used in products that contain binder.

Other Uses of Offals

0041 Collection of offals for edible use requires – at least –

inspection, washing, and trimming. The cost of these

procedures may not be justified by the value of some

offals. In this case the offals are disposed of or used in

other ways. The main alternatives are to render offals

to produce tallow and meat meal, or to use them as

pet food. Inspected offal which is not edible because

of contamination or disease status is rendered along

with other offals which are not required for edible use

or pet food, e.g., heads, hooves, and the residues of

gut material after collecting sausage casing and tripe.

0042 Offals collected for pet food may be subject to less

rigorous inspection, preparation, and trimming than

offals for human use and can be handled at a lower

cost. The main use of offals is in canned pet foods.

These products receive severe heat treatment, and

offals which retain form and texture, such as lung

and tripe, are most suitable. Liver, heart, and spleen

are also used in canned pet food.

0043 There are specialized uses for some offals. Pig and

beef pancreas glands are used to produce insulin

for the treatment of diabetes. However, insulin from

pancreas glands is being replaced by insulin produced

from bacterial fermentation.

0044The mucosa from the lining of lungs and intestines

is used to produce the anticoagulant, heparin. A

long-standing use of calf vells (abomasum) is in the

production of rennet.

See also: Beef; Meat: Slaughter; Preservation; Sausages

and Comminuted Products; Pork; Poultry: Chicken;

Ducks and Geese; Turkey