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with spirits), would also be lost using this pro-

cedure. The repeatability (95% confidence) of this

method is generally of the order of 0.6% absolute,

and laboratories are normally able to achieve this

level of precision.

0014 It is becoming increasingly common to use micro-

wave drying to determine the moisture content of

foods. It is essential when using this procedure to

insure that the microwave heating does not burn the

food and the settings on the microwave must be de-

termined with care. This can be achieved by compar-

ing the results of microwave drying with the more

traditional oven-drying reference method and

adjusting the drying time accordingly.

0015 For rapid results, instruments are available which

consist of a balance which has an infrared heater

above it. Samples are weighed on to the balance and

then immediately dried using the heating element to a

constant weight.

Connective Tissue Content

0016 Enforcement authorities are increasingly interested in

the connective tissue content (rind, skin, gristle, etc.) of

meat and meat products. Connective tissue content

is also used as a measure of the quality of exported

meat products within the EC. The amino acid hydro-

xyproline is present in animal protein collagen at a

relatively high and consistent level compared with

muscle proteins. The determination of hydroxyproline

content of meat and meat products therefore allows

an assessment of the level of connective tissue. This in

turn allows a decision to be made on whether the

amount of connective tissue in a product is acceptable.

0017 The method of analysis used for the determination

of hydroxyproline is essentially a colorimetric pro-

cedure. After hydrolysis of a test portion of the meat

in sulfuric acid at 105



C, the hydrolysate is filtered

and diluted. This is followed by an oxidation step

with chloramine T.

0018 The resulting solution is then treated with

p-dimethylaminobenzaldehyde, which produces a

red compound, the amount of which is measured

using a spectrophotometer.

0019 In order to calculate the amount of connective

tissue that is present in foods, a number of factors

have been derived (Table 3). The procedure docu-

mented by Lord and Swan is commonly used by

enforcement authorities to determine the connective

tissue content of meat and meat products.

Calculation of Meat Content and Added

Water Content

0020Analytical data can be used to calculate the apparent

total meat content of meat and meat products. This is

achieved by measuring the amount of nitrogen pre-

sent and applying standard factors to determine the

apparent fat-free meat content and, with a further

allowance for fat, the apparent total meat content.

This is the basic method described by Stubbs and

More, which has changed little since its publication

in 1919. This approach to calculating apparent total

meat content can be modified to allow for the

presence of the more complex ingredients now used

– such as soya – which contribute protein (and so

nitrogen), but not meat. Also, the lean meat content

can be estimated by further calculation allowing for

the level of fat deemed to be appropriate for lean

meat.

0021The principle of the Stubbs and More method

involves the estimation of the apparent fat-free meat

content, from the amount of nitrogen originating

from the meat. Factors are used for the conversion

of the nitrogen content to meat content. An allowance

is then made for the amount of meat fat to determine

the apparent total meat content. ‘Nitrogen factors’

are available for the conversion of the nitrogen con-

tent to raw meat equivalent for many meats. The

average nitrogen factors used for meat content calcu-

lation have been the subject of much debate; however,

the Nitrogen Factors Sub-Committee of the Analyt-

ical Methods Committee of the Royal Society of

Chemistry publish the most widely accepted values

(Table 4). It should be remembered that a nitrogen

factor is the average nitrogen content of the fat-free

meat and represents a range of values and not a single

exact value. A worked example, applying this ap-

proach to roast lamb, and including the relationship

between nitrogen content and protein content, is

given in Table 5.

0022The above basically holds true for meat and meat

products which consist essentially of meat. However,

for more complex products (e.g., sausages, burgers),

further corrections must be applied for any sources of

non-meat nitrogen. If these corrections are not ap-

plied, the calculation would give an artificially ele-

vated meat content result.

0023Lean meat content is often referred to by legisla-

tion. It is not possible to determine the lean meat

content of a food due to the variability of the

fat content of lean meat (e.g., the lean meat from

pork can naturally contain from less than 5% to

tbl0003 Table 3 Factors used to convert hydroxyproline data into

useful parameters

1. Hydroxyproline 37 ¼% Wet fat-free connective tissue

2. Hydroxyproline 1.28 ¼% Connective-tissue nitrogen

3. Hydroxyproline 8 ¼% Collagen

3794 MEAT/Analysis

over 12% fat). However, it is usual to estimate the

lean meat content by adding 10% of the fat-free meat

on to the fat-free meat content. This assumes that lean

meat contains 10% fat. Therefore, a food with an

apparent fat-free meat content of 67% would have

an apparent lean meat content of 74% (viz. 67 100/

90). Where the actual fat content of the food is less

than the 10% allowance being added, then it is usual

to add all of the fat content of the food on to the

apparent fat-free meat content to give an estimation

of the apparent lean meat content. This will also

equal the apparent total meat content.

0024 Added water is present in some whole-meat prod-

ucts such as ham and bacon due to the use of curing

solutions. Such added water is often subject to

maximum limits or must be declared in the labeling.

0025The amount of added water can be estimated, by

calculation, in various ways. The most widely used

formula for calculating the added-water content of

cured meat products is based on the Stubbs and More

approach. Using this method, the added water is cal-

culated by subtracting the total meat content and all

of the added ingredients from 100 (Table 6). This is

therefore an indirect method and the result would be

in error if any of the analytical parameters or the meat

content were incorrectly determined.

Species Testing

0026It is often necessary to check the species of meat

present in meat mixtures and, in some instances, of

individual pieces of meat. Over the last 30 years

tbl0004 Table 4 Sources of official nitrogen factors and hydroxyproline data for meat

Type of meat Nitrogen factor (NF) Reference Comment

Pork–general 3.5 Analyst 1991, 116, 761

Also Analyst 1986, 111, 969

Pork–leg 3.49 Analyst 1991, 116, 761

Also Analyst 1986, 111, 969

Pork–neck 3.38 Analyst 1991, 116, 761

Also Analyst 1986, 111, 969

Pork–hand 3.42 Analyst 1991, 116, 761

Also Analyst 1986, 111, 969

Pork–loin 3.66 Analyst 1991, 116, 761

Also Analyst 1986, 111, 969

Pork–belly 3.5 Analyst 1991, 116, 761

Also Analyst 1986, 111, 969

Beef 3.65 Analyst 1993, 118, 1217

Turkey–whole 3.65 Analyst 2002, 127, 859–869

Turkey–dark meat 3.45 Analyst 2002, 127, 859–869

Turkey–breast 3.9 Analyst 2002, 127, 859–869

Chicken (broiler) – whole, skin off 3.55 Analyst 2000, 125, 1359–1366 Contains data for skin, breast, leg, thigh

and dark meat of hen and broilers

Chicken (broiler) – dark meat, skin off 3.3 Analyst 2000, 125, 1359–1366 Contains data for skin, breast, leg, thigh

and dark meat of hen and broilers

Chicken (broiler) – breast, skin off 3.85 Analyst 2000, 125, 1359–1366 Contains data for skin, breast, leg, thigh

and dark meat of hen and broilers

Mutton 3.47 Analyst 1995, 120, 1823

Lamb 3.5 Analyst 1996, 121, 889

Kidney 2.7 Analyst 1966, 91, 538

Tongue – ox or pig 3.0 Analyst 1967, 92, 326

Veal 3.35 Analyst 1965, 90, 256

Ox liver 3.45 Analyst 1964, 89, 630

Blood 3.2 Analyst 1968, 93, 478

Pigs, liver 3.65 Analyst 1964, 89, 620

Includes hydroxyproline data.

tbl0005 Table 5 Example calculation to determine the meat content of roast lamb from analytical data

Fat 17.9%

Water 55.3%

Ash 0.7%

Nitrogen 4.18% (equivalent to 26.1% protein (4.18  6.25))

Carbohydrate 0

The appropriate nitrogen factor for lamb is 3.50

Apparent fat-free meat content ¼

4:18

3:50

100 ¼119%

and adding the fat content gives:

Apparent (or raw equivalent) total meat content ¼119.4 þ17.9% (fat) ¼137%

Note: Meat contents can exceed 100% because on cooking the moisture reduces and the nitrogen increases above the level naturally present in meat.

This gives a raw equivalent meat content of over 100%.

MEAT/Analysis 3795

methods have progressed from assessment of the

composition of the fat present in the meat, and elec-

trophoretic methods of protein separation and

identification, through to the use of serological tech-

niques. Current procedures are based on immuno-

logical techniques in the form of enzyme-linked

immunosorbent assays and dipstick tests to the

newer polymerase chain reaction methods which use

the sample’s DNA to identify the species present. As

yet, the methods do not offer sufficient quantitative

precision for it to be possible to determine precisely

(with certainty) the amount of the individual species

present.

0027 The immunological test takes the form of kits for

both raw and cooked meats. As an example, the kit

for cooked meat is a noncompetitive sandwich-type

enzyme immunoassay that uses a biotin-avidin en-

hancement process. The antibody is designed to rec-

ognize antigens in the cooked meat. Raw or uncooked

meat may be tested by heating prior to the extraction

of the target antigen. This kit is widely used within

the meat industry for routine meat species analysis.

However, it does not differentiate between poultry

species and hence results can only be reported as

poultry. A raw species kit, which is also available,

will differentiate between chicken and turkey meat.

0028 The relatively new methods use the analysis of the

DNA from the species concerned. These are gaining

popularity and are currently the subject of extensive

method development. In the cleaved amplified poly-

morphic sequences (CAPS) method, DNA is first ex-

tracted from the meat sample. A specific region of

the mitochondrial cytochrome b gene is then ampli-

fied using the polymerase chain reaction and the

amplified product is subject to digestion using a

range of restriction endonucleases. The products gen-

erated by the restriction endonucleases are subject to

electrophoresis on an agarose gel and stained with

ethidium bromide dye. The gel is visualized under

ultraviolet light and a photographic record of the

resulting patterns is obtained.

Spoilage

0029 During spoilage, the proteins present in meat break

down and the fat can become rancid. The assessment

of the freshness of meat can normally be easily

assessed from the odor of the food. It also often

includes a microbiological assessment and measures

to assess the breakdown of proteins and fat. With

respect to the microbiological aspects of meat spoil-

age, there are wide ranges of microorganisms that can

grow on meats and result in spoilage, including Pseu-

domonas, Enterobacteriaceae and lactic acid bac-

teria. The particular group of organisms responsible

for meat spoilage will vary from product to product,

depending on the chemical characteristics such as pH,

water activity, and storage conditions used, i.e., tem-

perature and atmosphere.

0030The protein breakdown can be assessed by using

the traditional total volatile nitrogen determination,

otherwise known as total volatile bases. This meas-

ures the protein breakdown products and is carried

out by distillation of a portion of the meat from

slightly alkaline conditions and titration of the

ammoniacal distillate with standard acid. As an

example, beef is normally considered to be acceptable

if the total volatile nitrogen value does not exceed

16.5 mg nitrogen per 100 g food.

0031During breakdown of meat, the fat may become

rancid and the measures of this rancidity which are

often used are those of free fatty acid content and

peroxide value of the fat. The free fatty acids are

derived from the breakdown of the triglycerides,

and the results of the free fatty acid determination is

generally expressed as oleic acid. The fat is extracted

from the food, and the acidity of a measured amount

of the fat is determined by titration. In order to carry

out this titration, the fat is dissolved in neutral alco-

hol and the solution is titrated with standard sodium

hydroxide solution using phenolphthalein indicator.

A preferred option, to avoid the need to evaporate

down the fat extract and hence incur further fat

breakdown, is to extract the fat from the meat with

chloroform and carry out the titration directly on this

extract. A portion of the filtrate can be evaporated

to determine the amount of fat present. It is general-

ly accepted that most fresh beef samples would not

have a free fatty acid content (calculated as oleic acid)

above 1.2%. The peroxide value is a measure of the

peroxides contained in the fat. During storage, per-

oxide formation is slow at first during an induction

period, which may vary from a few weeks to several

months, depending on the fat involved. It is usually

determined volumetrically from the reaction of

the bound oxygen with potassium iodide in acid

tbl0006 Table 6

Added water (%) ¼ 100  (% Apparent total meat content þ % salt þ % carbohydrate þ % other ingredients)

As an example, a sweet cured bacon containing salt (3%), sugar (2%), and with an apparent total meat content of 88%, would contain,

for example:

Added water (%) ¼ 100  (88 þ 3 þ 2) ¼ 7%

3796 MEAT/Analysis

solutions. The liberated iodine is then titrated with

sodium thiosulfate. Fresh oils normally have a perox-

ide value of well below 10 mmol kg

1

0032 As rancidity is a complex matter, it is advisable to

carry out as many tests as possible on doubtful

samples. Other tests that are used to evaluate the

oxidation of lipids include the Kreis test, the anisidine

value, and the thiobarbituric acid number.

0033 Data on the total volatile nitrogen and free fatty

acid values of individual chicken legs removed from

storage in a domestic refrigerator are shown in

Table 7. The literature available on the normal values

for these parameters is inadequate and often data

have to be derived from small surveys undertaken

when data are needed.

Differentiation of Fresh and Frozen-

Thawed Meat

0034 Legislation prohibits the sale of previously frozen

meat as ‘fresh’ and thawing and refreezing are

improper treatments of meat. Such treatment can

enhance the possibility of the increase of the popula-

tions of microorganisms, such as Salmonella, and

thus pose a serious health risk. Furthermore, the con-

sumer may be disadvantaged because fresh meat nor-

mally commands a higher price than frozen meat and

it is therefore important that it can be differentiated.

The usual means of determining whether meat has

been previously frozen and thawed is from the use

of the b-hydroxyl-coenzyme A dehydrogenase (b-

HADH) enzyme test. This test involves measuring

the activity of mitochondrial enzymes that are re-

leased when the meat is frozen and thawed. The

freezing and thawing of meat damages the muscle

mitochondria, which results in the partial release of

the mitochondrial enzymes into the sarcoplasm or

muscle juices. The enzyme that has most commonly

been used is b-HADH. The biochemical method was

developed by Gottesmann and Hamm in meat

press juice by means of a relatively simple spectro-

photometric enzyme assay and has been the subject

of research and validation. The activity of b-HADH

is measured by determining the rate at which

nicotinamide-adenine-dinucleotide (reduced NADH)

is converted to nicotinamide-adenine-dinucleotide

(NAD

). This conversion is dependent on the level

of b-HADH activity and can be measured by the

decrease of absorption of the reaction solution at

340 nm. Work carried out on chicken indicates that

the test will give an indication that it has been frozen

where the meat has been stored below 12



C. The

method has also been collaboratively tested.

See also: Fats: Occurrence; Immunoassays:

Radioimmunoassay and Enzyme Immunoassay; Meat:

Sources; Protein: Chemistry; Food Sources;

Determination and Characterization; Spoilage: Bacterial

Spoilage

Further Reading

Allen JC and Hamilton RJ (1994) Rancidity in Foods. 3rd

edition.

Billington M, Bowie H, Scotter S, Walker H and Wood R

(1992) The differentiation of frozen and frozen-thawed

poultry meat by the determination of the beta – hydro-

xyacyl-CoA-Dehydrogenase (HADH) activity of

chicken breast press juice: collaborative trial. JAPA 28:

103–116.

BS 4401 Part 1: (1998) ISO 936:1998, Methods of Test for

Meat and Meat Products, Determination of Ash content.

BS 4401 Part 2: (1980) ISO 937:1978, Methods of Test

for Meat and Meat Products. Part 2 Determination of

Nitrogen content (reference method).

BS 4401 Part 3: (1997) ISO 1442, Methods of test for Meat

and Meat Products, Determination of Moisture Content

(reference method).

BS 4401 Part 4: (1970) Methods of Test for Meat and Meat

Products. Part 4 Determination of Total Fat Content.

BS 4401 Part 5: (1996) Methods of Test for Meat and Meat

Products, Determination of Free Fat Content.

BS 4401 Part 11: (1995) ISO 3496:1994, Methods of test

for Meat and Meat Products Determination of Hydro-

xyproline content.

Davies AR (1994) Spoilage of raw meat. PHLS Micro-

biology Digest v11(2): 108–110.

Eburne RC and Prentice G (1994) Modified-atmosphere-

packed ready-to-cook and ready-to-eat meat products.

tbl0007 Table 7 Changes in chicken meat stored in a fridge at 4



Number of days after purchase Appearance and odor Total volatile bases (mg10 0 g

1

) Acidity of fat (%) (oleic)

0 Normal 12.8 0.54

Normal 12.0 0.51

5 Some off-odor; appearance normal 30.1 1.5

7 Off-odor; green/yellow discoloration 31.0 1.3

9 Increasing odor and color; slimy 39.7 1.3

12 Unpleasant odor, green color and

slimy consistency

46.4 1.7

Best before date.

MEAT/Analysis 3797

In: Man CMD and Jones AA (eds) Shelf life evaluation of

foods. Book Number 5571. Shelf F1. pp. 156–178.

Egan H, Kirk RS and Sawyer R (1981) Pearson’s Chemical

Analysis of Foods 8th edition.

Food Analysis Performance Assessment Scheme (FAPAS)

Sand Hutton, York YO41 1LZ UK: Central Science

Laboratory.

Gottesman P and Hamm R (1983) Fleischwirtsch 63(2):

219–221.

Her Majesty’s Customs and Excise Integrated Tariff of the

United Kingdom (2002).

Huis in’t Veld JHJ (1996) International Journal of Food

Microbiology 32(3).

Jackson TC, Acuff GR and Dickson JS (1997) Meat,

poultry, and seafood. In: Doyle MP, Beuchat LR and

Montville TJ (eds) Food Microbiology. Fundamentals

and Frontiers. ASM Press, Washington DC.

Lord and Swan (1984) Journal of the Association of Public

Analysts 22: 131–140.

McLean BD (1999) CCFRA Guideline NO. 22 Meat

and Meat Products: The Calculation of meat content,

added water and connective tissue from analytical

data 1999.

Stubbs G (1919) The estimation of the approximate quan-

tity of meat in sausages and meat pastes (1919) Geo.

Stubbs, OBE., FIC & A. More. ARCS, FIC. The Analyst

44: 125.

Nutritional Value

J Higgs and J Pratt, Meat & Livestock Commission,

Milton Keynes, UK

This article is reproduced from Encyclopaedia of Food Science,

Background

0001 This article considers the different animal species

available for human consumption and the signifi-

cance of the nutritional value of meat as a whole.

Increased awareness of animals as sentient beings,

and the option to elect to avoid eating meat in afflu-

ent societies, influences discussion of the role of meat

in the modern human diet.

0002 In theory, it is possible to construct both omnivor-

ous and vegetarian diets that meet dietary recommen-

dations, although allowing for the differences in

bioavailability of some micronutrients and practical

issues relevant to modern society (preparation time

and cooking); this task is easier for an omnivorous

diet. It is unknown whether or not there would be any

significant differences between two such diets that

would influence public health advice.

0003Of all foods, meat provides one of the widest ranges

of nutrients in useful amounts. This may be one of the

reasons for its importance throughout history as the

central focus of the diet, included particularly within

celebratory meals. It is perhaps the fact that meat has

been eaten as much for enjoyment as for its nutritional

qualities that allows any offending aspect of meat

production to affect its consumption by affluent

nations.

Types of Meat

0004The types of meat commonly consumed in different

countries are dependent on eating habits and the abil-

ity to rear the animals successfully, which is influenced

by local climate, geography, and economy. Sheep and

goat meat are more popular in developing countries,

while native llama, buffalo, and antelope are import-

ant parts of the local ecosystems in many areas,

especially Bolivia, Peru, Ecuador, Asia, and Africa.

0005Beef, lamb, pork, and chicken are the major meats

consumed in Western societies, with beef predomin-

ating. Although the total meat consumption in the UK

has remained fairly steady since the 1980s, consump-

tion of chicken, pork, and meat products has in-

creased, while that of beef and lamb has declined.

Major influences include increasing demand for con-

venience, a trend towards eating out of the home, and

a superior health image for poultry during this period.

Veal, horse meat, hare, rabbit, and game birds such as

duck and pheasant also contribute to meat intake.

With the establishment of farmed deer in recent

years, venison has become more popular and afford-

able, promoted for its low fat content. Commercial

rearing of ostrich meat is new to Europe and, like

emu, has grown rapidly in the USA. Both ostrich

and emu meat are promoted for their favorable fat

profile, which is similar to that of poultry and pork,

although the iron content of ostrich is closer to that of

beef and lamb.

0006Meat includes carcass meat and edible offals (organ

meats, e.g., liver, kidney, tongue, heart, sweetbreads

(thymus and pancreas), and tripe (stomach)). Meat

products is a term that includes the result of any type

of processing ranging from composite dishes such

as pies and ready-made meals to the addition of

other ingredients such as water to increase succu-

lence, curing, fermentation, and preparations such

as brawn, black pudding, meat bars (pemmican), etc.

Consumption

0007Meat consumption increases with affluence. Japanese

intake has increased to half that in the USA, and in

China, meat intake is also increasing dramatically

(Table 1).

3798 MEAT/Nutritional Value

Macronutrient Content

Protein

0008 Meat is a significant source of protein, which is of

high biological value. Within developed nations, meat

provides around 60% of protein intake compared

with only 15% in poorer nations. The protein content

of different meats and cuts varies inversely with fat

content. Meat is a rich source of the amino acid

taurine; this is essential in newborn infants as they

are unable to synthesize this amino acid from cysteine

in sufficient quantities. The significance of lower

levels of taurine in the breast milk of vegan mothers

is unknown.

Fat

0009 The total fat content varies with species and across

the carcass. Although the fat content of lean muscle

from most species is around 2–5%, the total fat con-

tent depends on rearing practices, feeding regimes,

and age. The level of fat trim sold with the meat

provides opportunities to affect the fat content as-

consumed further, through cooking and trimming by

the end user. This is illustrated by looking at the

changes seen in the fat content of pork since the

1970s (Figure 1). Trimming visible fat (subcutaneous

and intermuscular) has the most influence on the final

fat content, since the invisible (intramuscular) fat

makes a relatively small contribution to the total.

Table 2 provides UK data showing the range of trim-

mable fat on specific red meat cuts.

0010 Fat is lost on cooking meat, assuming that it is

allowed to escape, for example. The amount lost

depends on the initial fat content, and fully trimmed

lean meat loses little fat. The concurrent loss of mois-

ture on cooking meat obscures fat losses, as viewed in

composition tables.

tbl0001 Table 1 Meat consumption 1980s and 1990s (g per person

per day)

Country 1980s 1990s

USA 310 231

Australia 296 290

UK 201 204

France 290 305

Germany 269 261

Japan 100 123

China 26 108

The values quoted are from the OECD for the years 1982 – 84 and 1992,

respectively. The exception is China; these values are taken from Asia

Pacific Food Industry (1995) 7(11): 14, using the years 1979 and 1994. The

figures include bone weight.

Reproduced from Meat, Poultry and Meat Products: Nutritional Value,

Encyclopaedia of Food Science, Food Technology and Nutrition, Macrae R,

Robinson RK and Sadler MJ (eds), 1993, Academic Press.

1950s−1970s

1990s

7.9

3.9

3.9?

3.5

(L+F)

21.3 (L + F)

19.5 (L+F+T)

(L + Int)

(L only)

Breed and feed

changes

Cutting plant/

retail trimming

Back fat trim

Seam cutting

Cooking loss

Cooking losses mainly

moisture; not analysed

but probably near 3.9

(L only, when cooked)

Cooking loss and

trim/plate waste

Traditional

butchery

Modern

butchery

fig0001Figure 1 Change in fat content of pork loin for 100 g of raw

edible tissue. Key: (L þF), lean þfat, untrimmed; (L þF þT),

lean þfat, some trimming; (L þInt), lean þintermuscular fat; (L

only), lean only. Source of data: Untrimmed, UK Database 1970s;

untrimmed including rind, UK Database 1990s;

at retail, UK

Database 1990s (79% lean, 21% fat);

trimmed of all back fat,

UK Database 1990s;

fully trimmed, UK Database 1990s;

100 g

raw as-purchased, cooked, and fully trimmed.

From Holland B,

Welsh AA, Unwin ID, Buss DH, Paul AA and Southgate D (1991)

McCance & Widdowson’s,The Composition of Food. Royal Society of

Chemistry, with permission. 5

edn. Campridge: From Analytical

Methods Committee (1991) Nitrogen Factors for Pork: A Re-

assessment. Analyst 116: 761–766, with permission.

From Chan

W, Brown J, Lee FM and Buss DH (1995), Meat, Poultry and Game.

Supplement to McCance & Widdowson’s, The Composition of Food.

Cambridge: Royal Society of Chemistry/London: Ministry of Agri-

culture, Fisheries and Food, with permission. Reproduced from

Meat, Poultry and Meat Products: Nutritional Value, Encyclopedia

of Food Science, Food Technology and Nutrition, Macrae R, Robin-

son RK and Sadler MJ (eds), 1993, Academic Press.

tbl0002Table 2 Proportion of trimmable fat in some raw cuts of beef,

lamb and pork

Meat Means andranges(%)

Beef

Braising steak 7 (0 – 18)

Fore-rib 21 (10 – 35)

Sirloin steak 18 (6 – 34)

Lamb

Chump chops 21 (11 – 32)

Breast 33 (20 – 48)

Rack of lamb 22 (18 – 25)

Pork

Leg 18 (12 – 28)

Loin chops 25 (16 – 34)

Steaks 11 (3 – 35)

From Chan W, Brown J, Lee SM and Buss DH (1995) Meat, poultry and

game. Supplement to McCance and Widdowson’s The Composition of Foods.

Cambridge: Royal Society of Chemistry and the Controller of Her

Majesty’s Stationery Office.

MEAT/Nutritional Value 3799

0011 During the years following World War II, the em-

phasis for meat production was on maximizing its

energy (fat) content and minimizing cost in an attempt

to produce enough nutrient-dense food to improve the

nutritional well-being of the whole population. Thus,

in the 1970s, red meat and meat products contributed

27.4% to the total daily UK fat intake, and little of

this was trimmed away. In the early 1980s, diet and

health reports identified meat as a major contributor

to fat intake, and so started the negative health asso-

ciation with red meat. Poultry meat was recognized as

being significantly lower in fat and was recommended

in preference by health experts. The red meat industry

responded by reducing the fat content of red meat

once again. Selective breeding and feeding practices,

carcass classification changes to favor leaner produc-

tion, as well as butchery techniques (seaming out

whole muscles and trimming away all intermuscular

fat) have meant that the meat on sale in the 1990s is

much leaner than it was in the 1970s. The fat content

of the carcass has been reduced in the UK by over 30%

for pork (making British pork virtually the leanest in

the world), by 15% for beef, and by 10% for lamb.

Further reductions are anticipated for beef and lamb

in the future. Overall, little change has occurred in

poultry meat; most of the fat is in the skin, which is

48% fat.

0012 Minced meat, predominantly beef, has become

more popular in recent years, reflecting a move to

convenience and a more cosmopolitan approach to

meals. Although viewed as a fattier product, fat levels

have dropped to typically 15%, with some extra-lean

mince as low as 5%.

0013 Since food-composition tables throughout the

world have not kept pace with these changes, the

health image of red meat has suffered disproportio-

nately to the nutritional benefits it offers. Food-

composition tables from different countries (e.g., the

UK, USA, and Germany) vary due to the analysis of

different cuts, different consumer demands, and how

upto date the tables are. Data on the composition of

red meat are shown in Table 3, and a 1995 fat audit

for the UK to trace all fat in the human food chain

provides useful information to illustrate the reduction

in fat intake since 1982 from meat, compared with

other foods (Table 4).

0014 The fat content of meat products can vary consider-

ably, depending on the proportion of lean and fat

from meat as well as the other ingredients. Trad-

itional types such as sausages, pastry-covered pies,

and salami were high in fat, up to 50%, but modern

products include ready-made meals and prepared

meats, which can be low in fat (5%). The trend

downwards in fat of red meat is reflected in the re-

duced fat content of a number of meat products, such

as hams and sausages. Reduced fat versions of popu-

lar hamburgers and sausages continue to enter the

market, and utilization of fat replacers will enable

this trend to continue (Table 5).

Fatty Acids

0015As with other foods, meat contains a mixture of fatty

acids. As the fat content of red meat has reduced, so

the fatty acid mix has changed with the percentage of

saturated fat than in the past. Poultry fat is 30%

saturated, while pork, beef, and lamb are less than

50% saturated. The contribution made by meat to

dietary saturated fat is given for the UK (Table 6). The

principal saturated fatty acids are palmitic acid

(C16:0 and stearic acid C18:0, which are thought

not to raise blood cholesterol levels. There are

only minor amounts of myristic acid, the most

atherogenic.

0016Meat is one of the main contributors to the mono-

unsaturated fat content of the British diet, principally

oleic acid (C18:1) from red meat. Around 40% of the

fat in meat is monounsaturated. Ruminant meats also

contain trans fatty acids, contributing around 18% of

British intakes.

0017Recent international analyses of beef, lamb, and

pork demonstrate useful levels of long-chain polyun-

saturated fatty acids in pasture- and grain-fed animals,

specifically eicosatrienoic acid (20:3n-6), arachidonic

acid (20:4n-6), eicosapentaenoic acid (20:5n-3), and

docosapentaenoic acid (22:5n-3). Significant losses of

some fatty acids, particularly the more highly unsatur-

ated fatty acids (C20 and C22) that are more suscep-

tible to oxidation, occur in cooking. The small amount

of docosahexaenoic acid (22:6n-3) present in raw

samples is lost on cooking. The richest dietary sources

of 20:4n-6 include liver, kidney, and turkey, while

smaller quantities are found in beef, lamb, pork, and

chicken (Table 7). Grass-fed animals have higher con-

centrations of a-linolenic acid compared with grain-

fed animals, and beef and lamb have favorable n-6:n-3

ratios. Meat, along with fish, provides the only signifi-

cant dietary sources of C20 and C22 n-3 fatty acids,

and for countries like the UK, where fish intakes

remain low, the contribution to the diet from meat is

significant, despite absolute levels in meat being low

relative to those in fish (Table 8).

0018It is possible to manipulate the fatty acid profile of

meat to satisfy human nutritional concerns more

easily in monogastrics (pigs and poultry) than in

ruminants (cattle and sheep), where polyunsaturated

fatty acids are hydrogenated in the rumen. The fatty

acid profiles of meats will continue to change as

knowledge of their significance to human health

improves, such that food composition data for meat

can only represent a single point in time.

3800 MEAT/Nutritional Value

tbl0003 Table 3 Nutrient composition of different meats per 100 g

Nutrient Beef

(raw, with fat)

Bison

(raw)

Buffalo

(raw)

Chicken

(raw, skin/fat)

Duck

(raw, with fat)

Goat

(raw)

Kangaroo

(raw)

Lamb

(raw, withfat)

Ostrichmeat

(cooked)

Pork

(raw, withfat)

Rabbit

(rawmeat)

Tur ke y

(raw, skin/fat)

Veal

(raw)

Venison

(raw)

Energy (kJ) 945 456 610 840 1622 673 493 1024 548 924 573 556 523 431

Protein (g) 21.7 21.6 20.8 19.1 13.1 19.5 24.2 18.5 24.8 19.2 21.9 21.6 21.5 22.2

Fat (g) 15.5 1.8 7.1 13.8 37.3 7.9 2.3 19 2.8 16.1 5.5 5.2 4.4 1.6

SFA (g) 7.1 0.7 3.24 3.8 2 9.35 1.06 5.8 2.1 1.7 1.8 0.8

MFA (g) 7 0.7 3.13 6.4 3.2 7.23 0.89 6.6 1.3 1.9 1.9 0.4

PFA (g) 0.6 0.2 0.3 2.6 1 0.87 0.59 2.7 1.8 1.2 0.4 0.4

Cholesterol (mg) 61 62 100 110 78 81 65 53 78 57 50

Iron (mg) 1.56 2.6 2.7 0.7 1.3 1.95 6 1.23 2.98 0.63 1 0.6 0.7 3.3

Zinc (mg) 3.5 2.8 1.1 1 4.1 2.71 1.75 1.4 1.8 2.7 2.4

Calcium (mg) 6 7.5 7 8 9.5 3 1.69 22 6 6.5 5

Magnesium (mg) 22 14 25 23 tr 25

Copper (mg) 0.02 0.09 0.05 0.05 0.06 0.03 8 0.21

Selenium (mg) 5.93 12 0.07 11.6 12 8

Sodium (mg) 55 54 111 70 73 63 62 71 59 67 70 71 55

Vitamins

(mg) 0.09 0.06 0.11 0.14 0.15 0.08 0.8 0.1 0.07 0.09 0.16

(mg) 0.19 0.19 0.25 0.51 0.28 0.18 0.21 0.19 0.2 0.19 0.7

Niacin equivalents (mg) 8.24 6.3 10 5.9 4.9 7.8 9.5 12.5 11.5 9.8 6.7

(mg) 0.46 0.44 0.3 0.33 0.3 0.25 0.45 0.5 0.55 0.57 0.65

(mg) 1.61 1.28 tr 2 1.76 1 10 1 2 1

Folate (mg) 9.0 7 5.51 2.76 5 19 6

D(mg) 0.39 0.6 0.42 0.68 0.4 1.2 N

E (mg) 0.12 0.15 0.1 0.04 0.13 0.01 0.22 N

MFA, monounsaturated fatty acids; N, nutrient present but no reliable data on amount; PFA, polyunsaturated fatty acids; SFA, saturated fatty acids; tr, trace.

Data taken from relevant international food composition databases published between 1986 and 1995.

Micronutrient Content

0019 The micronutrient content of meat can make a sig-

nificant positive contribution to nutritional intakes,

since it is a relatively concentrated source of a large

number of vitamins, minerals, and trace elements,

and the bioavailability of several such as iron, copper,

and zinc is greater from meat than from plant foods.

Iron

0020 Meat, especially red meat and offal, is a rich source of

iron, a 100-g serving of beef rump steak providing

3 mg. Red meat contains 50–60% of its iron in the

heme form (from hemoglobin and myoglobin), and

this is absorbed by a more efficient mechanism than

nonheme iron, the sole source of iron in plant foods.

Moreover, heme iron is unaffected by the numerous

inhibitors of iron absorption such as phytate. Thus,

the absorption of iron from meat is typically

15–25%, twice that from plant sources. Meat also

plays a valuable role as an enhancer of iron absorp-

tion from plant foods, so the presence of meat in a

meal can double the amount of iron absorbed

from the other components of the meal. The exact

mechanism for this, although not confirmed, is

believed to be due to the iron-binding capacity of

cysteine within peptides following proteolysis

of meat muscle. Although the absolute iron content

of white meats, e.g., chicken, and meat products may

appear low compared with some plant food sources,

this enhancing function and better iron availability

make these foods useful contributors to iron intakes.

Cooking in iron or steel utensils can increase the iron

content of the meal owing to this enhancing effect of

meat. Meat is thus a particularly important influence

on iron intake and iron status. Serum ferritin levels,

which indicate iron stores in the body, are strongly

correlated with heme iron intake. Meat can have a

major impact in groups vulnerable to iron deficiency,

specifically toddlers, adolescents, and women of

child-bearing age.

Zinc

0021The best sources of zinc are meat, especially beef, lamb,

pork, poultry, and seafood. As with nonheme iron, the

bioavailability of zinc is reduced by inhibitors in the diet

such as phytate and oxalate, and is enhanced when

consumed with animal protein. In metabolic studies,

zinc absorption and retention are greater on diets with

a high meat content compared with those on a low meat

content. Lower plasma zinc levels in vegetarians and

vegans, despite higher intakes, suggest that meat has a

major influence on zinc status. Approximately 20 – 40%

of zinc is absorbed from meat, which is the major con-

tributor to zinc intakes in Western countries (Table 6).

tbl0004 Table 4 Total UK dietary fat

, per person, contributed from all

foods groups in 1982 and 1992

Food group Dietary fat (kgperperson per year)

19 82 19 92

Beef and veal 2.09 1.93

Lamb 0.66 0.51

Pork and products (1981, 1992) 6.54 4.36

Poultry meat 9.29 6.80

Fats and oils 17.40 21.98

Dairy fat (1983, 1992) 12.91 11.04

Fish and fish oil 4.40 2.20

Eggs 1.56 1.09

Chocolate 1.54 1.92

Cereals 0.92 1.05

Nuts 0.27 0.34

Contribution of fat from primary food source rather than the end product,

e.g., ‘Fats and oils’ includes fat used ultimately in such products as bakery

goods, meat products, and confectionery.

tbl0005 Table 5 Nutrient content for a range

of meat products per 100 g

Product Fat content (g; range) Energy (kJ; range) Energy (kcal; range) Iron (mg; range)

Bacon, all types 11.7–26.6 727–1388 174–332 0.4–1.1

Beefburgers, raw 6.2–25.4 472–1258 113–301 1.7–2.7

Chicken nuggets/fingers 1.5–17.1 552–1212 132–290 0.6–1.1

Cornish pasties 16.3–24.3 1066–1496 255–358 1.0–1.1

Frankfurters, cooked 20.0–31.0 1041–1400 249–335 1.1

Ham, all types 1.5–20.0 372–1003 89–240 0.6–0.8

Pastrami 3.2–7.2 477–736 114–176

Pate 11.9–33.0 811–1484 194–355 1.5–7.4

Pork pies 19.5–33.5 1329–1827 318–437 0.9–1.2

Pork sausages, raw 8.8–30.4 740–1446 177–346 0.8–1.0

Salami 28.3–52.3 1442–2249 345–538 1.3

Where available, ranges include low-fat versions of the product.

Data taken from: MLC (1996) Meat Products Composition Survey; Chan W, Brown J, Church SM and Buss DH (1996) Meat products and meat dishes.

(Available on request from MLC). Supplement to McCance and Widdowson’s The Composition of Foods. Cambridge: Royal Society of Chemistry and the

Controller of Her Majesty’s Stationery Office.

3802 MEAT/Nutritional Value

Selenium

0022 Selenium is added to animal feeds to prevent defi-

ciency. Concerns of excess build-up of selenium in

soil and water supplies as a consequence of this are

difficult to substantiate. The bioavailability of selen-

ium from plant foods was thought to be greater than

that from animal foods, but recent data demonstrate

that meat, both raw and cooked, provides selenium in

a form which is as bioavailable as that in cereals.

Meat provides on average 10 mg of selenium per

100 g and contributes around a quarter of daily

needs.

Vitamins

0023 Meat can make a significant contribution to intakes

of all B vitamins except folate and biotin. Pork and

pork products, such as bacon and ham, are particu-

larly rich sources of thiamin, typical servings provid-

ing the daily requirement. Liver and kidney provide

more than the daily requirement of riboflavin in less

than 100 g. Meat also provides the richest source of

niacin (half of which is derived from the amino acid

tryptophan) and vitamin B

. Per 100 g portion, veal

liver provides half the daily B

needs, and other meats

provide around a third. Organ meats are particularly

rich sources of folate and vitamin A (Table 9). Cur-

rently in the UK, liver is not recommended during

pregnancy, despite being an excellent provider of

iron and folate, owing to the very high levels of

retinol it contains, which may potentially cause

malformation of the developing fetus. Vitamin A in

its active form, retinol, is found only in foods of

animal origin, so meat provides a preformed source

of this vitamin.

0024Vitamin B

merits particular attention, since foods

of animal origin provide the only significant dietary

source. It is recommended that where meat and dairy

products are avoided, supplements should be taken.

In the past, some B

was provided from the soil on

poorly cleaned foods, which may in part explain the

apparent absence of deficiency in some vegan groups.

0025Pantothenic acid is universal in all living matter,

and rich sources include liver and kidney. Most of the

vitamin is leached into the drip loss associated with

frozen meat.

tbl0007Table 7 Fatty acid composition of muscle from English beef,

lamb, and pork

Fattyacid Percentage by weight of total fatty acids

Beef Lamb Pork

12:0 lauric 0.08 + 0.03 0.31 + 0.18 0.12 + 0.05

14:0 myristic 2.66 + 0.54 3.30 + 1.07 1.33 + 0.20

16:0 palmitic 25.0 + 1.77 22.2 + 1.56 23.2 + 1.46

16:1 cis 4.54 + 0.81 2.20 + 0.26 2.71 + 0.45

18:0 stearic 13.4 + 1.84 18.1 + 2.80 12.2 + 1.11

18:1 trans 2.75 + 1.28 4.67 + 1.67 nd

18:1n-9 oleic 36.1 + 2.87 32.5 + 3.25 32.8 + 3.91

18:1n-7 vaccenic 2.33 + 0.40 1.45 + 0.26 3.99 + 0.59

18:2n-6 linoleic 2.42 + 0.63 2.70 + 0.86 14.2 + 4.09

18:3n-6 g-linolenic nd nd 0.06 + 0.03

18:3n-3 a-linolenic 0.70 + 0.18 1.37 + 0.48 0.95 + 0.33

20:2n-6 nd nd 0.42 + 0.11

20:3n-6 0.21 + 0.06 0.05 + 0.04 0.34 + 0.09

20:3n-3 0.007 + 0.011 nd 0.12 + 0.05

20:4n-6 arachidonic 0.63 + 0.21 0.64 + 0.23 2.21 + 0.73

20:4n-3 0.08 + 0.03 nd 0.009 + 0.022

20:5n-3 EPA 0.28 + 0.11 0.45 + 0.13 0.31 + 0.15

22:4n-6 0.04 + 0.02 nd 0.23 + 0.07

22:5n-3 0.45 + 0.14 0.52 + 0.14 0.62 + 0.20

22:6n-3 DHA 0.05 + 0.02 0.15 + 0.05 0.39 + 0.23

DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; nd, not

detected.

From Enser M, Hallett K, Hewitt B, Fursey G and Wood J (1996) Fatty acid

content and composition of English beef, lamb and pork at retail. Meat

Science 42: 443–456.

tbl0008Table 8 Contribution to UK diet of n-3 and n-6 polyunsaturated

fatty acids from meat and fish (g per person per year)

Food n-3 n-6

Beef 17.7 39.1

Lamb 13.0 17.5

Pork 55.7 451.6

Total – red meat 86.3 508.2

Total – fish 12.9 1.5

From Ulbricht (1995) Fat in the Food Chain. A report to the Ministry of

Agriculture, Fisheries and Food. Available from MAFF library.

tbl0006 Table 6 Contribution made by meat to nutrient intake

Nutrient Percentage of totaldailyintake

contributedbymeat for UK

Energy 12.9

Protein 38.0

Fat 20.0

Saturated fatty acids 19.2

Monounsaturated fatty acids 23.8

Polyunsaturated fatty acids 15.0

Iron 15.0

Zinc 33.3

Retinol 32.2

Vitamin D 18.5

34.3

18.6

Niacin equivalents 42.9

25.0

37.5

Folate 5.4

Vitamin E 1.2

Vitamin C 0.4

Per capita consumption figures for beef and veal, mutton and lamb, pork,

bacon and poultry for 1995 in the UK.

Reproduced from Meat, Poultry and Meat Products: Nutritional Value,

Encyclopaedia of Food Science, Food Technology and Nutrition, Macrae R,

Robinson RK and Sadler MJ (eds), 1993, Academic Press.

MEAT/Nutritional Value 3803