Original Research 63

Nutrafoods (2012) 11:63-67DOI 10.1007/s13749-012-0020-4

123Healthcare

Lactose content in typical Italian Gorgonzola cheese: a pilot study

Mario Del Piano, Roberto Tari, Stefania Carmagnola

Received: 24 February / Accepted 21 March 2012 Springer Healthcare CEC Editore 2012

Correspondence to:Mario Del Piano

mario.delpiano@libero.it

Abstract Background Gorgonzola is an Italian blue-veined

cheese in which Penicillium roqueforti develops as a

blue-green mould. Gorgonzola cheese is produced

in the Italian Piedmont and Lombardy regions, ac-

cording to a procedure precisely defined by a Pro-

tected Denomination of Origin (PDO) protocol.

Due to the production technique and the presence

of lactic acid bacteria, Gorgonzola cheese is consid-

ered completely free of lactose by the United States

Department of Agriculture (USDA) classification.

Short-ripened Gorgonzola cheese (dolce variety),

on the other hand, may contain residual lactose.

The aim of this study was to investigate the actual

lactose content in dolce Gorgonzola samples ob-

tained from market.

Methods and results Two different groups of Gor-

gonzola samples were analysed. Groups were com-

posed of 11 (Group A) and 15 (Group B) samples

respectively, produced in 26 different plants, all

members of the Consorzio del Gorgonzola (No-

vara, Italy). The collected samples were sent to two

commercial laboratories in Novara, Italy under re-

frigeration (ca. 6C) and immediately analysed or

frozen. Lactose was detected in only one sample of

the two groups, at a clinically non-significant level

(0.063 g/100 g).

Conclusion Gorgonzola cheese is virtually lactose-

free and may be suitable for lactose-intolerant pa-

tients who want to enjoy a popular Italian cheese.

Introduction Gorgonzola is a member of the blue-cheese family;

it is a ripened, uncooked variety of cheese that is

white in appearance with internal blue-green

mould in which Penicillium roqueforti develops. Its

production is well established in Italy: the first ev-

idence of Gorgonzola cheese preparation dates back

to 879 AD in Gorgonzola, near Milan. In 1996,

Gorgonzola obtained a Protected Designation of

Origin (PDO) from the European Commission

(Commission Regulation No 1107/96). Today, Gor-

gonzola is mainly produced in two northern Italian

regions, Piedmont and Lombardy, according to a

well defined protocol (Fig. 1).

A starter bacteria preparation is added to whole cows

milk, along with spores of the mould Penicillium glau-

cum. Penicillium roqueforti, used in Roquefort cheese,

may also be used. The whey is then removed during

curdling and the obtained product is allowed to age

Keywords: Gorgonzola cheese,fermentation, lactose,lactase

Mario Del Piano (), Roberto Tari, Stefania CarmagnolaDivisione di GastroenterologiaAzienda Ospedaliera-Universitaria Maggiore della Caritvia Mazzini 18, 28100 Novara, Italymario.delpiano@libero.it

64

has a more ivory coloured and softer texture, with

quite a reddish rind and light grey-green veins be-

cause of the growth of P. roqueforti in fissures through-

out the cheese matrix. The taste ranges from mild to

sharp, depending on the age and the cheese type.

The characteristics of several European blue-veined

cheese varieties have been studied by various authors

because the ripening process, owing to the mould

growth, is more complex than in other cheese vari-

eties. An intervarietal study of Gorgonzola and other

blue-veined cheeses (English Stilton, Danish Dan-

ablu and Irish farmhouse varieties Cashel and

Chetwynd) revealed that the profile of Gorgonzola

was quite different from the other cheeses, i.e., Gor-

gonzola is characterised by extensive degradation

of both as1- and b-caseins, and contains consider-

ably higher concentrations of small peptides and

free amino acids [13]. Another study has also com-

pared different varieties of Gorgonzola and another

five blue-veined cheese varieties (Bleu de Bresse,

Cabrales, Danablu, Roquefort and Stilton) and found

that Gorgonzola had pH higher than 6.0, and ca.

30% fat, 20% protein and 45% moisture [4].

Due to the consolidated production technique and

the presence of lactic acid bacteria, Gorgonzola

cheese is considered lactose-free in the USDA classi-

fication (2008). However the USDA did not consider

the possible differences between the dolce (at least

50 days ripened) and piccante (at least 80 days

ripened) types. The presence of a residual amount

of lactose is in fact possible in the dolce type, due

to its short ripening.

Lactose is a natural sugar mostly found in milk and

milk products (Table 1). It needs to be hydrolysed

by lactase in the intestine in order to be absorbed

and used for energy production. Many people have

low actual levels of lactase activity, but most do not

experience signs and symptoms when exposed to

lactose. People are only defined as lactose intoler-

ant if their low lactase levels are associated with

IBS-like symptoms, such as bloating, abdominal

cramps and diarrhoea when they consume lactose-

containing food.

at low temperatures. During the ageing process metal

rods are quickly inserted and removed, creating air

channels that allow the mould spores to grow into

hyphae and cause the cheeses characteristic veining.

Gorgonzola is typically aged for three to four months.

The length of the ageing process determines the con-

sistency of the cheese, which gets firmer as it ripens.

The presence of blue moulds gives Gorgonzola its

typical appearance; the high biochemical activity of

these moulds enzymes produces its characteristic

aroma and taste. The colour of the cheese ranges

from white to straw-yellow, depending on the various

cheese types, so esportazione cheeses are whiter with

darker blue veins, while the dolce variety of the cheese

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123Healthcare

Bovine milk

Pasteurisation (ca. 73 C for 40 sec)

Cooling of milk to 30 C

Inoculum with natural starters (ca. 106 cfu ml1 of cheese milk)Streptococcus thermophilus, Lactobacillus delbrueckii

subsp. bulgaricus and lactococcus

Inoculum of Penicillium roqueforti (ca. 10 ml 100 l1 of milk)

Addition of liquid calf rennet (ca. 50 ml 100 kg1)

Coagulation of milk at 30-34 C after 10-15 min

Cutting of the coagulum(size of the curd after cutting = ca. 2.0-2.5 cm)

Removal of the curd

Held at 18 C for 10 h with 4 turns of the curd

Salting of the cheese at 22 C for 40 h(ca. 200 g of NaCl spread over each cheese)

Ripening at 4-6 C for 83 days(environmental humidity, ca. 85-90%)

Piercings of the curd after 12 and 20 days

Figure 1 Protocol to be followed for the production of Gorgonzola cheese (2006 Consorzio per la tutela del formaggio Gorgonzola;consorzio.gorgonzola@gorgonzola.it)

65

tional benefit from both human and animal milk,

and is thus vital in mammals pups. It shows a

tight control of developmental expression, being

expressed at low levels in foetal life and increasing

around birth; it is only expressed in small-intestinal

enterocytes. Lactase declines after weaning in most

adults but persists into adult life in many others.

The age of onset of the down-regulation of lactase

activity is different in different populations [3, 4].

Lactase persistence, the genetic trait in which in-

testinal lactase activity persists at childhood levels

into adulthood, varies in frequency in different hu-

man populations, being most frequent in northern

European and certain African and Arabian nomadic

tribes, who have a tradition of drinking fresh milk

(Fig. 2) [5]. Selection is likely to have played an im-

portant role in establishing these different frequen-

cies since the development of agricultural pastoral-

ism 9000 years ago [6, 7].

The ability to digest milk as adults is likely to be

adaptive, owing to the increased nutritional bene-

fits from milk (carbohydrates, fat, protein and cal-

cium) and also because milk is an important source

of water in arid regions. Considering the symptoms

of lactose intolerance, which include water loss

from diarrhoea, individuals with the lactase per-

sistence-associated alleles, able to tolerate milk, are

likely to have had a strong selective advantage [8

10].

Gorgonzola cheese should be suitable for lactose-

intolerant individuals, since it is inoculated with

different lactic bacteria that digest the lactose ini-

tially present in the cheese.

Lactic bacteria use lactose as an energy source with

the production of organic acids, especially lactic

acid, and secondary heat release (fermentation).

They belong to 5 genera (Lactococcus, Lactobacillus,

Streptococcus, Leuconostoc and Pediococcus) with dif-

ferent species distributed in all natural environ-

ments. Before the introduction of milk refrigera-

tion, in the Po valley, the thermophilic species,

Streptococcus thermophilus and Lactobacillus bulgari-

cus, were particularly diffused. In time, the ther-

Lactase splits lactose into two simple sugars, glucose

and galactose, which can be absorbed and enter

the bloodstream. If lactase activity is insufficient,

most of the lactose in food reaches the colon un-

processed, where intestinal bacteria digest it, pro-

ducing an excess of gas, and inducing bloating,

pain and diarrhoea.

Three types of lactose intolerance have been de-

scribed:

(1) Primary lactose intolerance is a normal effect of

ageing in some people. Normally, the body pro-

duces large amounts of lactase at birth and during

early childhood, when milk is the primary source

of energy. Lactase production usually decreases as

the diet becomes more varied and less reliant on

milk. This gradual decline may lead to symptoms

of lactose intolerance.

(2) Secondary lactose intolerance is usually due to ill-

nesses or injury that affect lactase production in

the small intestine. This can occur as a result of

coeliac disease, gastroenteritis and inflammatory

bowel diseases like Crohns disease. Treatment of

the underlying disorder may restore lactase levels

and improve signs and symptoms, but the process

of recovery is often slow.

(3) Genetic absence of lactase activity. This is a very

rare condition in which lactose intolerance passes

from generation to generation following a pattern

of autosomal recessive inheritance.

Lactase activity is necessary to obtain full nutri-

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Table 1 Lactose in different cheeses

Cheese Lactose (g/100 g)

Cows mozzarella 1.52Goats cheese 1.52Crescenza 1.52Roman ricotta 3.2Fresh cow cheese 4Edam 1Swiss cheese 0.06Cream cheese 6Gorgonzola 0Parmigiano Reggiano 0

Source: USDA National Nutrient Database for Standard Reference, Release 19,2008

66

Laboratorio, Novara, Italy), where they were imme-

diately analysed or frozen. The samples of the first

group (Group A) were analysed only by the Biolab

Research srl laboratory, while those of the second

group (Group B) were analysed by both laboratories.

Gorgonzola cheese was kindly supplied by the Con-

sorzio del Formaggio Gorgonzola (Novara, Italy).

Each sample was produced by one of 26 different

members of the Consorzio. The bovine milk used

had a pH of 6.65 and contained 4.90% lactose, 3.20%

protein and 3.60% fat. The starter used was a naturally

fermented cheese whey that contained S. ther-

mophilus, Lactobacillus delbrueckii subsp. bulgaricus and

lactococci in a ratio of about 1:0.8:0.6. Lactose content

in the samples was determined, in both laboratories,

using a commercial Boehring Kit. In this method,

lactose is hydrolysed by -galactosidase (lactase) toD-glucose and D-galactose. The galactose is oxidised

by galactose dehydrogenase to galactonic acid with

the conversion of NAD+ to NADH. The NADH

formed during this reaction is stoichiometrically

equivalent to the amount of lactose and is measured

spectrophotometrically at 334, 340 or 365 nm. Glu-

cose is phosphorylated to glucose-6-phosphate (by

hexokinase and ATP), which is then oxidised by

mophilic species were the dominant population of

natural lacto-grafts prepared to drive the dairy lactic

fermentation in Gorgonzola cheese. A good culture

medium for Gorgonzola production contains a pop-

ulation of over a billion live and vital cells per mil-

lilitre, with a ratio of S. thermophilus to L. bulgaricus

of approximately 60/40. It is able to transform lac-

tose completely into lactic acid and ATP.

Gorgonzola cheese could thus be consumed by lac-

tose-intolerant individuals. But it should not be

overlooked that although the lactose content is neg-

ligible in ripened varieties, residual lactose could

be present in the short-ripened Gorgonzola, the

dolce variety, which now accounts for 90% of to-

tal Gorgonzola use. This justifies this pilot study,

aiming to investigate the lactose content in short-

ripened Gorgonzola samples of the dolce variety.

Methods Two different groups of Gorgonzola samples, bought

directly from a market, were analysed. The groups

were composed of 11 (Group A) and 15 (Group B)

samples, respectively. The collected samples were sent

in anonymous refrigerated packs (ca. 6C) to two dif-

ferent laboratories (Biolab Research srl and EQS

Nutrafoods (2012) 11:63-67

123Healthcare

Swed

ishDanes

IrishBri

tish

Finland S

wedis

h spkers

Germans-N

WCzec

hsSw

iss

Finland F

innish

spkers

Austr

ians

Germans-S

W

Frenc

h-nort

h

Span

ish

Eston

ians

Sloven

ians

Hungarians

Polish

Lapps

Frenc

h-sou

th

Kildin

Saam

i

Komi

Perm

iak

Italians-n

orth

Gree

ks

Russians

Roma

/Sinti

Italians-s

outh

Sicilians

Turks

1

0.6

0.2

North West South East

0.1

0.9

0.8

0.7

0.5

0.3

0.4

0

Figure 2 Lactase persistence decreases according to northsouth gradient in the European population (Source: Swallow DM.Genetics of lactase persistence and lactose intolerance. Annu Rev Genet 2003, 37:197219)

67

Even if additional data regarding all the centres of

the Consorzio are needed to confirm these conclu-

sions, we think it is reasonable to assume that Gor-

gonzola cheese, in all its varieties (including the short-

ripened dolce), is suitable for lactose-intolerant

people who want to enjoy a popular Italian cheese.

Acknowledgement

The authors are grateful to Consorzio per la tutela del formaggio

Gorgonzola and its president, Dr. Renato Invernizzi, for supplying

the Gorgonzola cheese.

Conflict of interest

The authors declare that they have no conflict of interest relating

to the publication of this manuscript.

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NADP+ in the presence of glucose-6-phosphate de-

hydrogenase. The NADPH formed during this reac-

tion is quantified spectrophotometrically and stoi-

chiometrically related to lactose concentration

(Boehringer Mannheim, 1986). The detection limit

of the kit is 0.035 g/100 g.

Results In the first group of samples (Group A) lactose was

detected only in one sample (#6, 0.063 g/100 g).

In the second group of samples no lactose was

found (Table 2).

DiscussionThe study shows that Gorgonzola cheese is virtually

completely free of lactose. Lactose was in fact de-

tected only in one sample, at a level (0.063 g/100

g) of no clinical significance and attributable to the

high sensitivity of the laboratory technique used.

Considering the dimension of the problem of lac-

tose intolerance and the increasing attention clini-

cians pay to food allergies and intolerances, this pi-

lot study is important in determining the virtually

total absence of lactose even in the dolce (short-

ripened) variety of Gorgonzola cheese produced in

26 different plants by members of the Consorzio.

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123Healthcare

Table 2 Lactose content in the Gorgonzola samples of the two groups

Sample Result

Group A1 n.d2 n.d3 n.d4 n.d5 n.d6 0.063 g/100 g7 n.d8 n.d9 n.d10 n.d11 n.d

Sample Result

Group B1 n.d2 n.d3 n.d4 n.d5 n.d6 n.d7 n.d8 n.d9 n.d10 n.d11 n.d12 n.d13 n.d14 n.d15 n.d