Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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Tyramine in Cheese

0007 In common with foods such as red wine, hung game,

soused herrings, and yeast extracts, certain cheeses

(e.g., mature Cheddar, Roquefort, and Gruye

re) con-

tain an amino acid derivative known as tyramine.

0008 In sensitive individuals, tyramine can provoke mi-

graine and skin rashes. This may occur, for example,

in those taking drugs that block the enzyme mono-

amine oxidase, which metabolizes tyramine. (See

Migraine and Diet.)

Trends in Cheese Consumption

0009 Table 3 shows the consumption of cheese in different

countries. Compared with most European countries,

cheese consumption in the UK is low. Consumption is

particularly high in France and The Netherlands.

0010In the UK, cheese consumption has risen from

4.7 kg per person per year in 1966 to 9.8 kg per

person per year in 1998, according to National

Dairy Council estimates (Figure 1). Data from the

National Food Survey, conducted by the UK Ministry

of Agriculture, Fisheries and Food, indicate that

cheese consumption is greater in higher income

groups and smaller households. There are no strong

regional differences.

Importance of Cheese for Different

Groups

0011As a product of milk, cheese confers similar nutri-

tional benefits. In particular, it is a rich source of

protein, calcium and vitamins A, B

(riboflavin), and

. It is also a useful source of highly bioavailable

tbl0001 Table 1 Nutritional composition (per 100 g) of some hard cheeses

English Cheddar Cheshire Blue Stilton Edam Reduced-fat Cheddar

Energy

(kcal) 412 379 411 229 261

(kJ) 1708 1571 1701 957 1091

Protein (g) 25.5 24.0 22.7 32.6 31.5

Carbohydrate (g) 0.1 0.1 0.1 Trace Trace

Sugars (g) 0.1 0.1 0.1 Trace Trace

Fat (g) 34.4 31.4 35.5 25.4 15.0

Saturates (g) 21.7 19.6 22.2 15.9 9.4

Monounsaturates(g) 9.4 9.1 10.3 7.4 4.4

Polyunsaturates (g) 1.4 0. 9 1.0 0.7 0.4

Sodium (mg) 670 550 930 1020 670

Dietary fiber (g) Nil Nil Nil Nil Nil

Vitamin A (mg) 336 387 386 200 182

Thiamin (mg) 0.03 0.03 0 .03 0.03 0.03

Riboflavin (mg) 0.42 0.48 0.43 0.35 0.53

Nicotinic acid (mg) 0.09 0.11 0.49 0.07 0.09

Potential nicotinic acid from tryptophan (mg) 6.00 5.64 5.34 6.12 7.41

Vitamin B

(mg) 0.10 0.09 0.16 0.09 0.13

Folic acid (mg) 37 40 77 40 56

Vitamin B

(mg) 1.2 0.9 1.0 2.1 1.3

Pantothenic acid (mg) 0.38 0.31 0.71 0.38 0.51

Biotin (mg) 3.1 4.0 3.6 1.8 3.8

Vitamin C (mg) Trace Trace Trace Trace Trace

Vitamin D (mg) 0.26 0.24 0.27 0.19 0.11

Vitamin E (mg) 0.54 0.70 0.61 0.48 0.39

Vitamin K ( mg) N/A N/A N/A N/A N/A

Calcium (mg) 740 560 320 770 840

Chlorine (mg) 1010 830 1410 1570 1110

Copper (mg) Trace 0.13 0.18 0.05 0.05

Iodine (mg) 46 (46) (46) N/A N/A

Iron (mg) 0.2 0.3 0. 3 0.4 0.2

Magnesium (mg) 26 19 20 39 39

Phosphorus (mg) 490 400 310 530 620

Potassium (mg) 79 87 130 97 110

Selenium (mg) 12 (11) (11) N/A 15

Zinc (mg) 2.3 3.3 2. 5 2.2 2.8

N/A: no reliable figures available. ( ): estimate.

Source: Holland B, Unwin ID and Buss DH (1989) Milk Products and Eggs. The fourth supplement of McCance and Widdowson’s The Composition of Foods

4th edn. Cambridge: Royal Society of Chemistry, and Ministry of Agriculture, Fisheries and Food, with permission.

1116 CHEESES/Dietary Importance

zinc. In addition, cheese is a very versatile food that

can be incorporated into many different dishes. It

keeps well if properly stored in the refrigerator,

wrapped in greaseproof paper or foil. Hard cheeses

such as Cheddar freeze well and can be kept for up to

3 months. On thawing, best results are achieved if the

cheese is allowed to defrost gradually, preferably in

the refrigerator.

0012 Mild hard cheeses and fresh soft cheeses such as

cottage cheese can be introduced into a child’s diet

from the age of 6 months. Cheese can be a useful

snack food for children. It is one of the few foods

that do not contribute to dental caries, and it may

even have a protective effect against dental decay,

perhaps by controlling the pH at the surface of the

tooth. Some dentists recommend a small piece of

cheese at the end of a meal for this reason. (See Dental

Disease: Role of Diet.)

0013Calcium requirements are particularly high during

pregnancy, and cheese, an excellent source of cal-

cium, is therefore a valuable food for pregnant

women. However, as a precaution, pregnant women

are advised to avoid mold-ripened soft cheese such as

Brie and Camembert because of the increased chance

of their containing Listeria monocytogenes, the bac-

terium that causes listeriosis. Most healthy people are

unaffected by listeriosis, but pregnant women are at

a greater risk. Fresh soft cheeses, e.g., cottage cheese,

tbl0002 Table 2 Nutrient composition (per 100 g) of soft cheese

Soft, fresh Surface-mold-ripened

Cottage

cheese:

plain

Fromage

frais:

plain

Fromage

frais: plain,

verylow fat

Quark Brie Camembert

Energy

(kcal) 98 113 58 74 319 297

(kJ) 413 469 247 313 1323 1232

Protein (g) 13.8 6.8 7. 7 14.6 19.3 20.9

Carbohydrate (g) 2.0 5.4 6 .5 3.8 Trace Trace

Sugars (g) 2.0 5.4 6. 5 3.8 Trace Trace

Fat (g) 3.9 7.1 0. 2 Trace 26.9 23.7

Saturates (g) 2.4 4.4 0.1 Trace 16.8 14.8

Monounsaturates(g) 1.1 2.1 0.1 Trace 7.8 6.9

Polyunsaturates (g) 0.1 0.2 Trace Trace 0.8 0.7

Sodium (mg) 380 31 (33) 45 700 650

Dietary fiber (g) Nil Nil Nil Nil Nil Nil

Vitamin A (mg) 46 100 3 2 320 283

Thiamin (mg) 0.03 0.04 (0.03) (0.04) 0.04 0.05

Riboflavin (mg) 0.26 0.40 (0.37) 0.30 0.43 0.52

Nicotinic acid (mg) 0.13 0.13 (0.14) 0.19 0.43 0.96

Potential nicotinic acid from tryptophan (mg) 3.24 1.59 1.81 3.43 4.53 4.91

Vitamin B

(mg) 0.08 0.10 (0.07) 0.08 0.15 0.22

Folic acid (mg) 27 15 (15) 45 58 102

Vitamin B

(mg) 0.7 1.4 (1.4) 0.7 1.2 1.1

Pantothenic acid (mg) 0.40 N/A N/A 0.44 0.35 0.36

Biotin (mg) 3.0 N/A N/A 3.0 5.6 7.6

Vitamin C (mg) Trace Trace Trace 1.0 Trace Trace

Vitamin D (mg) 0.03 0.05 Trace Trace 0.20 0.18

Vitamin E (mg) 0.08 0.02 Trace Trace 0.84 0.65

Vitamin K (mg) N/A N/A N/A N/A N/A

Calcium (mg) 73 89 (87) 120 540 650

Chlorine (mg) 550 100 (89) 110 1060 1120

Copper (mg) 0.04 Trace (0.01) 0.06 Trace 0.07

Iodine (mg) N/A N/A N/A 4 N/A N/A

Iron (mg) 0.1 0.1 (8) Trace 0.8 0.2

Magnesium (mg) 9 8 (110) 11 27 2.1

Phosphorus (mg) 160 110 (8) 200 390 310

Potassium (mg) 89 110 (110) 140 100 100

Selenium (mg) (4) (2) (2) N/A N/A N/A

Zinc (mg) 0.6 0.3 (0.3) 0.9 2.2 2.7

N/A: no reliable figures available. ( ): estimate.

Source: Holland B, Unwin ID and Buss DH (1989) Milk Products and Eggs. The fourth supplement to McCance and Widdowson’s The Composition of Foods

4th edn. Cambridge: Royal Society of Chemistry, and Ministry of Agriculture, Fisheries and Food, with permission.

CHEESES/Dietary Importance 1117

and hard cheeses such as Cheddar, are considered

safe in this respect. The pH of Cheddar and other

such cheeses limits the growth of this bacterium,

which prefers more alkaline conditions. See Listeria:

Listeriosis.

0014 For vegetarians who include dairy products in their

diet, cheese can be an important source of protein,

vitamin B

and minerals. Vegans, who exclude all

foods of animal origin, will require vitamin-B

-forti-

fied foods or supplements, since the vitamin is found

only in dairy foods and other foods of animal origin,

such as meat. (See Vegetarian Diets.)

0015Hard cheeses, such as Cheddar, have a very low

lactose content and can be a useful source of calcium

and other essential nutrients for those people who are

lactose-intolerant. (See Food Intolerance: Lactose

Intolerances.)

See also: Dental Disease: Role of Diet; Food Intolerance:

Lactose Intolerance; Listeria: Listeriosis; Migraine and

Diet; Vegetarian Diets

Further Reading

International Dairy Federation (1999) The World Dairy

Situation 1998. Bulletin of the IDF 339: 52

Ministry of Agriculture, Fisheries and Food (1999)

Household Food Consumption and Expenditure, 1998.

London: The Stationery Office.

National Dairy Council (1999) Dairy Facts and Figures.

London: NDC.

Renner E (1983) Milk and Dairy Products in Human

Nutrition. Munich: Volkswirtschaftlicher.

Renner E (1989) Micronutrients in Milk and Milk-based

Food Products. London: Elsevier Applied Science.

Scott R (1981) Cheesemaking Practice. London: Applied

Science.

tbl0003 Table 3 Estimates of cheese consumption in a selection of

countries, 1998

Cheese consumption

(kg perperson per year) in1998

Australia 8.9

Canada 10.8

Argentina 10.9

Hungary 7.1

Germany 20.5

Denmark 16.4

Finland 17.0

France 23.6

Ireland 8.3 (1997 figure)

Israel 16.5

Iceland 18.8

Italy 19.0

Japan 1.6 (1997 figure)

The Netherlands 16.6

Norway 14.2

South Africa 0.9

Spain 8.4

Sweden 16.8

UK 9.7

USA 13.1

Source: International Dairy Federation (1999) The World Dairy Situation

19 9 8. Bulletin of the IDF 339, 52, with permission.

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

cheese, kg/head/y

fig0001 Figure 1 Trends in consumption of cheese in the UK. Source: National Dairy Council (1999) Diary Facts and Figures. London: NDC.

1118 CHEESES/Dietary Importance

Mold-ripened Cheeses:

Stilton and Related Varieties

P A Atkinson, Formerly of Long Clauson Dairy Ltd,

Melton Mowbray, UK

This article is reproduced from Encyclopaedia of Food Science,

Stilton and Related Varieties

0001 Varieties of internally mold-ripened, hard-pressed

cheeses include Stilton, Blue Shropshire, Blue Chesh-

ire, Blue Wensleydale, Buxton Blue, Blue Vinney,

Danish Blue, Roquefort, and Gorgonzola. All these

varieties of blue cheese are considered to be hard

cheeses, although only the Blue Cheshire and Blue

Wensleydale are actually pressed during manufacture.

The other varieties are turned regularly during

manufacture, the only pressure being the weight of

the curd.

Specifications and Standards

0002 The 1970 Cheese Regulations in the UK require that

all full-fat hard cheese shall contain not less than 48%

milk fat in dry matter, and not more than 48% mois-

ture. In addition, the standards for Stilton are stated

in Schedule 2 of these regulations as follows:

Fat in dry matter Moisture

Blue Stilton 48% 42%

White Stilton 48% 46%

0003 The Stilton Cheese Makers Association (SCMA)

has registered the name of Stilton and defined Blue

Stilton as follows:

A fully matured, blue-veined Blue Stilton Cheese is an

English made cheese produced within the Counties of

Leicestershire, Derbyshire and Nottinghamshire with no

applied pressure, forming its own crust or coat and made

in cylindrical form from full cream milk produced in

English and Welsh Dairyherds.

0004 The SCMA also describes flavor, internal and

external body, and shape. These will be discussed in

more detail below when grading is described.

Method of Manufacture – Stilton Cheese

0005 Stilton cheese is made at nine factories within the

three counties stipulated in the SCMA schedule, and

the overall process is shown in Table 1.

0006 It is made from cows’ milk produced locally, except

in times of peak production when cows’ milk may be

used from anywhere within England and Wales. The

milk is collected in bulk and it is now all pasteurized

(71.6



C/15 s); the last factory stopped using raw milk

in 1989. After pasteurization the milk is cooled to

between 26 and 32



C according to season and indi-

vidual factory variations, and put into cheese vats.

(See Milk: Processing of Liquid Milk.)

0007The temperature of milk in the vat at this stage has

a very strong influence on the texture of the curd

formed and, as a result, will have a marked effect on

the openness of the curd when the cheese is made.

Seasonal and geographical variations in milk compos-

ition require variations in the cheese-making tech-

nique to give consistent cheese quality; one of these

is variation in milk temperature.

0008Starter cultures are added to the milk in the vats

at varying rates from 50 ml to 2 l per 4500 l (1000

gallons), or as recommended by the supplier if con-

centrated (direct vat inoculation, DVI) cultures are

used. Considerable variations in starter culture are

used by the different manufacturers of Stilton, but

one consistent factor is slow, but persistent, acid de-

velopment throughout the early stages of the cheese-

making process. The presence of Lactococcus lactis

biovar. diacetylactis and Leuconostoc spp. in low

numbers in the culture can help to achieve this. (See

Cheeses: Starter Cultures Employed in Cheese-

making.)

0009Spore suspensions of Penicillium roqueforti are

added to the vat at the same time as the starter cul-

ture. The strains used vary with different manufactur-

ers and can have an effect on the final flavor of the

mature cheese. The cheese-makers’ judgment in the

selection of mold strains is very important in ensuring

consistent product quality and market acceptance.

0010Rennet is added to the milk after a period of

ripening, usually of 1–2 h. As the starter addition

rate is very low, there is a negligible rise in acidity.

This necessitates an increase in the quantity of rennet

tbl0001Table 1 Flowchart of the manufacture of Stilton

Time/age Temperature

Milk pasteurization 0

Starter addition 0 26–32



Rennet addition 1–2 h 26–32



Cutting 1–2 h 26–32



Whey separation 1–2 h 26–32



Milling and salting 24 h 26–32



Mold filling and turning

Maturation 5–7 days 26–30



Coating 26–30



Maturation: white store 5–10 days 13–15



Maturation: blue store 6–12 weeks 13–16



Piercing 6–7 weeks 13–16



Grading 9–10 weeks

Extended maturation As directed by flavor 5



Packing and distribution 8



CHEESES/Mold-ripened Cheeses: Stilton and Related Varieties 1119

used to give a satisfactory coagulation. The rate of

rennet addition is between 1.18 and 1.48 l per 4500 l

of milk (0.025–0.03%). This compares with 0.88–

1.03 l per 4500 l for normal cheddar cheese manufac-

ture, where a very much higher starter inoculation is

used, and higher acidities are achieved. Animal rennet

is generally used, although a ‘vegetarian Stilton’ is

now being produced in which microbial rennet is

used. Some manufacturers have suggested that cheese

of satisfactory quality can be made with microbially

derived coagulants, but that the texture of the cheese

is not the same as that made from calf rennet. (See

Cheeses: Chemistry of Gel Formation.)

0011 The curd is cut using American knives or nylon

grids which give cubes with 1.25 cm sides. The cut-

ting time is determined by the experience and skill of

the cheese-maker and is influenced by the firmness of

the curd. After cutting, the curds and whey separate

and the curd sinks to the bottom of the vat. Over a

further period of usually 1–2 h, syneresis continues

and, when the curd occupies about half the volume

of the original milk, the curd may be stirred to aid

subsequent whey drainage. A further period is then

allowed for whey separation. At this stage the whey is

removed progressively, taking 12–18 h before the last

of the whey is drained away. As the whey is drained,

the curd is cut into blocks to aid drainage. At the end

of the draining period the titratable acidity will have

risen to between 1.1 and 1.3% lactic acid, and the

curd texture should be firm but crumbly (easily

broken).

0012 The curd is then passed through a peg mill which

breaks it into pieces 1.25–2.5 cm in diameter. Salt is

added to the curd and mixed evenly at the rate of

2½% w/w. After salting, the curd is put into cylin-

drical, open-ended molds (22.8–25 cm diameter),

with 9–11 kg of curd per mold, depending on the final

weight of each cheese. At this stage the curd is put into

the molds with no pressure. The presence of the salt

increases syneresis and curd drainage. (See Cheeses:

Chemistry and Microbiology of Maturation.)

0013 After 1–2 h drainage the molds are turned over.

This first turn is quite critical and failure to turn at

this stage can result in uneven drainage of the cheese

at later stages in the maturing process. The cheeses

are then turned daily for a further 5–7 days, allowing

migration of the salt through the curd and further

whey drainage. During this period the curd becomes

much firmer and, at the end of this period, the cheese

will slide easily within the mold when it is turned.

0014 The mold is then removed and the cheeses are

rubbed with the flat side of a knife to give a smooth

coat over the whole surface. This is thought to

prevent ingress of oxygen at too early a stage in the

ripening process.

0015The temperature and humidity from filling the vat

with milk until the cheeses have been rubbed or

coated are maintained at 26–30



C and 90% relative

humidity (RH). This insures that the curd does not get

cold and does not dry out and become discolored. It

also influences the microflora of the finished cheese

by encouraging the growth of starter organisms,

particularly the slower-growing Lactococcus lactis

biovar. diacetylactis.

0016After coating, the cheeses are transferred to the first

maturing room or ‘white room’, so called because the

cheeses remain in this room for 5–10 days, and at the

end of this time those produced for White Stilton

(without the blue mold being added) may be sold.

Cheeses are turned daily at this stage.

0017The humidity in the white room is maintained at

85–90% RH, but the temperature is reduced to 13–



C. This allows the cheese to cool and the coat to

dry. Humidity control at this stage is important as too

low an RH would cause excessive drying and the

coats would crack. Too high an RH would result in

wet coats which would encourage the wrong micro-

flora and could result in off-flavors developing; for

example, Brevibacterium linens frequently occurs on

wet-coated cheese and can cause very uncharacteris-

tic flavors to develop. Also, as the natural coat flora

begins to develop and get thicker, a condition known

as ‘slip coat’ can occur. In this case, proteolysis occurs

just beneath the coat and causes the whole coat to slip

down the cheese and fall off, so making the cheese

unsaleable.

0018After 5–10 days in the white room, the cheeses are

transferred to a blue maturing room where turning

continues daily, but may become less frequent as

the coat develops and the cheeses start to dry out.

The temperature and humidity levels are controlled at

13–16



C and 90% RH in these stores.

0019At approximately 6–7 weeks after production

(from the day of rennetting), the cheeses are pricked,

spiked, or skewered. This operation involves piercing

the cheese with stainless-steel needles to allow air

into the cheese, thus encouraging growth of the Peni-

cillium spores put into the milk.

0020Up to this stage the pH within the cheese has ini-

tially dropped to 4.8–5.0, but, as the mold grows, the

pH rises. In addition, the temperature rises as a result

of the metabolic activity within the cheese. Lipolysis

and proteolysis occur, releasing carbon dioxide and

ammonia. The ammonia can frequently be detected in

the atmosphere in the maturing rooms at levels up to

30–40 p.p.m. When this occurs it is necessary to in-

crease the ventilation in order to reduce it to an

acceptable level.

0021As the maturing process continues, the piercing is

usually carried out twice more with between 100 and

1120 CHEESES/Mold-ripened Cheeses: Stilton and Related Varieties

300 needle insertions at each skewering. In order to

insure a good blue mold development, it is essential to

have created an open-textured curd which will allow

easy penetration of the mold hyphae between the curd

particles. This will give the characteristic blue veining

effect which radiates out from the center of the cheese

where the spike holes are most dense.

0022 After a period of 2–3 weeks from the onset of mold

growth, the blue veining should have radiated out to

the edge of the cheese. At this stage the cheeses are

transferred to a cool store at 2–5



C where mold

growth will be somewhat retarded. Flavor and tex-

ture continue to develop and the byproducts of fat

and protein degradation accumulate in the cheese.

0023 With the advent of the Food Hygiene Amendment

Regulations (1989) and the need to store mold-

ripened cheese at temperatures below 8



C(5



from 1993), the flavor development in cold storage

is slowed down, but still continues and can give

a strong mature flavor (and texture) after a further

2–6 weeks of storage.

Grading

0024 Grading usually takes place at 8–9 weeks and in-

volves examination of every cheese for the following

characteristics.

External

.0025 Shape – should be regular and uniform.

0026 Coat – should be dry, firm, slightly wrinkled,

intact, drab in color, and free from surface mold

blemishes.

Internal

.0027 Flavor should be clean and mild.

0028 Body should be uniform creamy white except for

blue-green mold radiating from the center.

0029 Texture should be velvety or flaky and open with

an absence of discoloration, gas holes, or chalki-

ness.

0030 The variability within Stilton makes it necessary to

examine each cheese individually. It is not possible to

take a random sample out of a larger batch, as is

normally done with the other UK hard cheeses.

Modern Approaches to Manufacture

0031 The current trend in the marketplace is towards a

more mature-flavored Stilton, which has been de-

scribed as ‘vintage’ or ‘extra mature.’ This is Stilton

which has been allowed to develop a stronger flavor

either in the maturing stores or in cold stores.

0032In recent years, some manufacturers have moved

away from the manual handling of the curd at the

stage where it is being made in the vat. Fully enclosed

vats have been used which allow mechanical cutting

of the curd followed by very gentle transfer of the

curds and whey into drainers where the curd is separ-

ated. Another alternative involves vats that open

completely at one end, allowing the curd to move on

to draining tables. However, the most successful in-

novation in this area has been the transfer of curds

and whey from vats to drainers through pipes.

0033Mold-turning systems have been tried in vari-

ous forms ranging from very sophisticated pallet-

handling systems to more simple pallet inverters.

They all work on the principle that it is quicker and

cheaper to turn pallets containing 64 cheeses than to

turn each individual cheese by hand.

Packing

0034Traditionally, Stilton was always sold as a whole

cheese wrapped in vegetable parchment. However,

in recent years, the proportion of prepacked cheese

for supermarket sales has increased to the point at

which prepacked Stilton accounts for more than 50%

of sales.

0035After cutting into triangular portions from the

round cheese, prepacked Stilton is almost always

wrapped in polyvinylidene chloride (PVDC) film; it

is always sold with the crust on. In recent years, there

has been some interest shown in alternative packing,

and modified-atmosphere packing (MAP) has been

tried. Alternative films with greater oxygen permea-

bility have also been tried. (See Chill Foods: Effect of

Modified-atmosphere Packaging on Food Quality;

Chilled Storage: Use of Modified-atmosphere Pack-

aging.)

0036The problem with Stilton cheese is that the absence

of oxygen eventually causes the loss of the blue color,

which progressively changes through green to yellow

and then disappears. This means that vacuum

packing in barrier bags has a very limited application.

The other alternative is an oxygen-permeable barrier

or a loose wrap which allows oxygen in and thus

maintains the blue mold. This will also support the

growth of any other aerobic organisms which may be

present; this includes Penicillium roqueforti, which is

quite acceptable as blue veining but is unacceptable as

adventitious growth on the cut surface of the cheese.

This latter growth is usually seen after 4–5 weeks

under refrigeration.

0037The reduction in product temperature during stor-

age has had the effect of extending the shelf-life

slightly, but it only slows the adventitious growth of

the mold, it does not stop it.

CHEESES/Mold-ripened Cheeses: Stilton and Related Varieties 1121

0038 Another method of packing Stilton that has gained

considerably in popularity in recent years is putting it

into ceramic jars with a wax or plastic seal. This

involves breaking the cheese into small pieces and

pushing them into the jars. Alternatively, some

companies are using an extrusion technique to fill

the jars. It has always been found necessary to put a

note on the pot/jar advising the customer that the blue

veining will have disappeared in storage, and that

removal of the wax seal will result in it returning

after about 1 h.

Hygiene

0039 Increased awareness of the need for high standards of

hygiene in food production and distribution has

resulted in a great deal of legislation being intro-

duced. The food industry has also introduced a

number of Codes of Practice to guide manufacturers

through the pitfalls of Listeria and Salmonella.(See

Listeria: Properties and Occurrence.)

0040 Stilton cheese is covered by the Code of Practice for

the Production of Soft and Mould-Ripened Cheese

which has been produced by the UK Dairy Trade

Federation.

0041 The result of manufacturers’ increasing awareness

of the problems of bacterial contamination has had

the effect of making dramatic changes in the construc-

tion of buildings and the training and control of staff.

Some aspects of the manufacturing procedures have

come under very close scrutiny; for example, the last

factory producing cheese from raw milk has now

decided to pasteurize its milk. It is argued that, in

some cases, higher hygiene standards are being

achieved at the expense of a loss of ‘character’ and

‘individuality’ in some of the speciality cheeses, such

as Stilton.

Related Varieties

0042 Although a number of other internally mold-ripened

cheeses can be found worldwide, the most famous are

Roquefort and Gorgonzola. The origins of Roquefort

can be traced back with some degree of certainty to

the fifteenth century, and the name is now inter-

nationally recognized for a cheese made from sheeps’

milk and matured in huge limestone caves in the

region of Aveyron, France. The method of manufac-

ture is broadly similar to that of Stilton, except that

the milk is not pasteurized. The strain of P. roqueforti

may also be unique to the region, but the differences

in flavor between Roquefort and Stilton arise mainly

from the higher content of short-chain fatty acids

associated with sheeps’ milk. (See Sheep: Milk.)

0043Gorgonzola derives its name from a village in Italy

where it is supposed to have originated around 1000

years ago. It is made from cows’ milk, and again

derives its veining from a strain of Penicillium.

0044More recent in origin is Danublu or Danish Blue

cheese, which is extensively manufactured in Den-

mark, North America, and Australia. The process is,

in essence, a more industrial version of Stilton manu-

facture, in that mechanization is heavily involved,

and a more limited ripening period insures a rapid

throughput of the product; as a result, connoisseurs

claim that it lacks the unique character of the more

traditional blue cheeses. (See Cheeses: Dietary Im-

portance.)

See also: Cheeses: Starter Cultures Employed in Cheese-

making; Chemistry of Gel Formation; Chemistry and

Microbiology of Maturation; Dietary Importance; Chill

Foods: Effect of Modified-atmosphere Packaging on Food

Quality; Chilled Storage: Use of Modified-atmosphere

Packaging; Listeria: Properties and Occurrence; Milk:

Processing of Liquid Milk; Sheep: Milk

Further Reading

Davis JG (1976) Cheese, vols 1–4. London: Churchill

Livingstone.

Robinson RK (ed.) (1990) Dairy Microbiology, 2nd edn.

London: Elsevier.

Scott R (1981) Cheesemaking Practice. London: Applied

Science.

Seth RJ and Robinson RK (1988) Factors contributing to

the flavour characteristics of mould-ripened cheese. In:

Robinson RK (ed.) Developments in Food Microbiology.

London: Elsevier.

Surface Mold-ripened Cheese

Varieties

M J Sousa, University College, Cork, Ireland

Surface Mold-ripened Varieties

0001Surface mold-ripened cheeses represent a relatively

small proportion of world cheese production, but

they are becoming increasingly popular with con-

sumers. In surface mold-ripened cheese varieties (e.g.,

Brie and Camembert), mold grows as a mat on the

surface, whereas blue-veined varieties (See Cheeses:

Mold-Ripened Cheeses: Stilton and Related Varieties)

are characterized by the growth of Penicillium

roqueforti in fissures throughout the cheese. Hybrid

1122 CHEESES/Surface Mold-ripened Cheese Varieties

mold-ripened cheeses are also produced (e.g., Cam-

bazola); these have a growth of white mold on the

surface and blue mold in the interior.

000 2 Surface mold-ripened cheeses are soft varieties

characterized by the growth of white mould (Peni-

cillium camemberti) on the surface of the cheese

(Figure 1). The first microorganisms that become

established on the surface are yeasts, including

Debaromyces spp., and Kluyveromyces spp. Geotri-

chum candidum also becomes established at this time,

although its growth may be limited if the level of salt

is high. Growth of P. camemberti is observed after

6–7 days of ripening, and this mold forms the charac-

teristic mat on the surface of the cheese. After the

surface of the cheese has been neutralized by yeast

and moulds ( *15–20 days), aerobic bacteria (par-

ticularly micrococci and coryneforms), which are in-

hibited by the low initial pH, begin to grow.

000 3 Surface mold-ripened varieties originated in France

a few hundred years ago; Camembert and Brie, which

originated in the eighteenth century, are prime

examples of this type of cheese. Camembert is a

small flat cylindrical ( *10 cm diameter, 5 cm thick

and *250 g) surface mold-ripened cheese that

originated in Normandy, France; it has a moisture

content of 46–47% and fat-in-dry-matter (FDM) of

at least 40%. Traditionally, Camembert has been

manufactured from raw milk (e.g., Camembert de

Normandie), but nowadays, industrial Camembert

is manufactured from pasteurized cows’ milk in

large, automated factories. Camembert has a close,

smooth texture that usually becomes soft and

spreadable, depending on the degree of maturation.

Young Camembert has a mild, slightly aromatic

taste, but as ripening progresses, it develops a dis-

tinctive, piquant flavor. Brie is a flat cylindrical

surface mold-ripened cheese with a larger diameter

than Camembert, which it resembles closely in flavor,

texture and manufacturing protocol. Carre

de l’Est

is a square (10cm side and 2.5cm thick) surface

mold-ripened cheese that originated in eastern

France; it has a moisture content of 50–53% and an

FDM of 45–50%. It resembles Camembert and Brie,

although its flavor is normally milder. Neufcha

tel

cheese is manufactured near Rouen, France, at the

farm level, in a wide variety of shapes and dimen-

sions; the ripened cheese has a moisture content of

51–53% and an FDM of 45–51%. Tomme de St.

Marcellin is a flat, cylindrical (8–10 cm diameter

and 2–3cm thick) cheese that was manufactured

traditionally from goats’ milk but is now made from

cows’ or sheep’s milk or a mixture of these milks.

There are many minor goats’ milk cheese varieties

that develop a surface mold growth during ripening,

but the microflora of these minor varieties is often

uncontrolled. The flavor of such cheeses is usually

strong (mainly due to the presence of short-chain

fatty acids), giving the products a characteristic

flavor, and their rinds are often colored as a result of

the growth of bacteria.

Production of Surface-mold Cheeses

0004There are several basic steps in the manufacture of

cheese. See Cheeses: Chemistry and Microbiology of

Maturation. Acidification, dehydration, shaping, and

salting, in the usual order of occurrence, are common

to most varieties; the reason for the individuality of

each variety is due mainly to differences in detail

(Figure 2).

0005These five operations, along with the chemical

composition of the milk, determine the degree of

dehydration. The flavor, aroma, and texture of the

finished product are determined by the moisture con-

tent, salt level, pH, and microflora, and by regulating

and controlling the biochemical changes that occur

during the ripening process.

0006The manufacture of surface-mold cheese begins by

selecting milk of high quality, both chemically and

microbiologically. Raw milk is still sometimes used

for both commercial and farmhouse cheesemaking;

however, cheese milk is now usually pasteurized or

heat-treated immediately before use. In addition to

killing pathogens, pasteurization eliminates certain

other indigenous microorganisms, and hence cheese

of a more uniform quality can be produced. The

surface microflora is often more complex than that

of the core, particularly in cheeses made from raw

milk by traditional technology.

fig0001 Figure 1 Examples of surface mold-ripened cheeses (Maison

du Lait, Les pate

s molles a

croute fleurie, Centre Interprofis-

sionaldeDocumentationetd’InformationLaitie

res,www.cidil.fr).

CHEESES/Surface Mold-ripened Cheese Varieties 1123

0007 Once the milk has been selected and pretreated

(if desired), the acidification process is started and

continues for up to 24 h. It is now almost universal

practice to use a starter culture of known lactic acid-

producing bacteria, the predominant function of

which is to produce acid at the appropriate rate

during cheesemaking. The lactic starters used for

Camembert and other surface-ripened cheeses are

generally homofermentative mesophiles (e.g., Lacto-

coccus lactis ssp. lactis and Lc. lactis ssp. cremoris)

that produce lactic acid by the hexose diphosphate

pathway. The rate of acidification for Camembert

cheese is slower than for hard varieties (e.g., Cheddar;

See Cheeses: Manufacture of Hard and Semi Hard

varieties of Cheese) owing to the quantity of starter

added to cheese milk, usually *0.1% and 1–2%

starter for Camembert and Cheddar, respectively.

0008 At the same time, the milk can be inoculated with

microorganisms that will later make up the surface

flora (i.e., a suspension of spores of P. camemberti).

Usually, CaCl

(0.02%) is added to the milk to

promote coagulation.

0009 Coagulation of the casein component of the milk

protein system involves forming a gel, which entraps

the fat, water, salts, and lactose. Chymosin is the

principal proteinase in traditional rennet used for

cheesemaking, and its main role is to specifically

hydrolyze the Phe

105

–Met

106

bond of the micelle-

stabilizing protein, k-casein, leading to coagulation

in the presence of Ca

2þ

at a temperature > 20



0010 A rennet-induced gel or coagulum is quite stable

until it is cut or broken, which causes syneresis. Brie

and Camembert are high-moisture cheeses (45–55%

moisture), and to prevent excessive syneresis, the co-

agulum is cut or broken into very large pieces, and the

curds are not cooked and only very slightly stirred in

the whey, thus discouraging dehydration. Tradition-

ally, an alternative means of whey and curd separ-

ation, called ‘dipping,’ is practiced, in which the

uncut coagulum is scooped from the vat into perfor-

ated molds, where drainage occurs. To facilitate

industrial-scale manufacture, the coagulum for Brie

or Camembert is first cut into large cubes and then

transferred to molds without cooking.

0011After molding, the body of curds in the molds is

turned at intervals over a period of 3 h and allowed to

cool overnight; Brie and Camembert are pressed

under their own weight only. Shortly after manufac-

ture, the pH of the cheese is low (4.6–4.9).

0012Surface mold-ripened cheeses are generally salted

by immersion in brine for long enough to give an

overall salt content of 1.5–2.5%. Generally, salting

stops the production of acid in the curd, preventing a

further decrease in pH. Along with having a direct

effect on cheese flavor, the salt encourages curd syn-

eresis and therefore has an effect on the moisture

content; it reduces the water activity in the curd and

influences the activity of rennet, indigenous milk

enzymes, and other enzymes. The Na

of the salt

exchanges with the calcium in the curd matrix, caus-

ing dissociation of proteins, and thus enhances the

emulsification of fat by the protein matrix.

0013In surface mold-ripened varieties, mold spores

are introduced as a secondary starter during the

Mesophilic

starter

(0.1−0.25%)

Acidified milk

CaCl

(0.02%)

Mold spores

Rennet

(0.015%)

Coagulum

Cutting

Molding

Whey

Mature cheese

Ripening (4 8C)

Packing

Ripening

(10−12 8C, 85−95% RH for 10−12 days)

Drying

(18 8C, 70−80% RH)

Brine salting at 16−18 8C

for a period of time depending on size

(e.g., for 150 g, ~100 min)

Resting and turning

(12 h at 18−20 8C)

Milk

Pasteurization (72 8C

15 s)or

Thermization (63 8C 30 min)

fig0002 Figure 2 Manufacturing protocol for Camembert or Brie cheese.

1124 CHEESES/Surface Mold-ripened Cheese Varieties

cheesemaking process. Generally, P. camemberti

spores are sprayed on to the surface of each newly

shaped cheese, although it is now industrial practice

to inoculate the cheese milk with spores before co-

agulation. Under suitable conditions [10–12



C and

85–95% relative humidity (RH) for 10–12 days],

these spores result in a white mold developing on

the outside of each cheese. This mold gives the cheese

its characteristic appearance and produces enzymes

that play a major role in the hydrolysis of the lipids

and proteins during ripening. After mold develop-

ment, cheeses are packaged in waxed paper and

placed in wooden or cardboard boxes prior to final

ripening at 4



C for a further 7–10 days. In traditional

Camembert, in which ripening continues for up to 12

weeks, the mold is subsequently overgrown by Brevi-

bacterium linens and other coryneform bacteria to

form the yellow crust, a distinct sulfur flavor, and

the very soft texture of extra-mature Camembert.

Biochemical Pathways during Ripening

0014 Three main biochemical events occur during cheese

ripening: metabolism of lactose and lactic acid

(generally called glycolysis), lipolysis, and proteolysis

(Figure 3). (See Cheeses: Chemistry and Microbiology

of Maturation.)

0015Cheese ripening can be a relatively slow process,

but in the case of Camembert and other soft cheeses,

ripening occurs very rapidly, owing to their moisture

content and the rapid growth of surface mold.

Metabolism of Lactose and Lactate

0016During the manufacture of cheese curd, the lactose in

the milk is converted mainly to l-lactate by starter

bacteria. In surface mold-ripened cheeses, the lactic

acid produced by the starter culture is utilized by

the secondary microflora, first by G. candidum and

yeast, principally D. hansenii, followed by P. camem-

berti, all of which catabolize lactate to CO

and H

and hence have a major role in the deacidification

of the cheese. There is clear evidence of this event in

the dramatic increase of the surface pH during the

sixth and seventh days, as the mold grows. Deacidifi-

cation occurs initially at the surface, resulting in a pH

gradient from the surface to the core, which causes

lactate to diffuse outwards. Neutralization of the sur-

face causes precipitation of Ca

2þ

at the surface as

(PO

)

, causing minerals in the cheese curd to

migrate to the surface, developing a gradient within

the cheese, which has a major effect on cheese texture.

This loss of calcium, as a consequence of neutraliza-

tion, leads to considerable softening of the body of

Camembert, as calcium is necessary for the integrity

Increase in pH

+ H

Volatile flavor compounds

Free amino acids

Enzymatic and chemical

modifications

Volatile flavor compounds

Chymosin

and plasmin

Intermediate-

sized peptides

Proteinases from

Lactococcus

Short peptides

Peptidases of

Lactococcus

and NSLAB

Caseins

(a) (b)

Triglyceride

Lipase

(c)

Lactose

Fermentation by Lactococcus

COOH

Lactate

Free fatty acid

Volatile flavor compounds

fig0003 Figure 3 Summary of the biochemical pathways involved in the ripening of surface mold cheeses; (a) proteolysis, (b) lipolysis and

(c) glycolysis and their role in flavor biogenesis. Adapted from McSweeney PLH and Sousa MJ (2000) Biochemical pathways for the

production of flavour compounds in cheeses during ripening. A review. Lait 80: 293–324.

CHEESES/Surface Mold-ripened Cheese Varieties 1125