Blue cheese is a general classification of cheeses that have had
cultures of the mold
Penicillium added so that the final product is
spotted or veined throughout with blue, or blue-grey mold and carries
a distinct smell, either from that or various specially cultivated
bacteria. Some blue cheeses are injected with spores before the curds
form, and others have spores mixed in with the curds after they form.
Blue cheeses are typically aged in a temperature-controlled
environment such as a cave.
Blue cheese can be eaten by itself or can
be spread, crumbled or melted into or over foods.
The characteristic flavor of blue cheeses tends to be sharp and salty.
The smell of this food is due both to the mold and to types of
bacteria encouraged to grow on the cheese: for example, the bacterium
Brevibacterium linens is responsible for the smell of many blue
cheeses, as well as foot odor and other human body odors.
2 Nutritional information
3.2 European Union
4 Physical-chemical Properties
5 See also
7 External links
Blue cheese is believed to have been discovered by accident when
cheeses were stored in natural temperatures and moisture-controlled
caves, which happen to be favorable environments for many varieties of
harmless mold. It was moist in the cave so the mold would form.
According to legend,
Roquefort was discovered when a youth, eating a
lunch of bread and ewes' milk cheese, abandoned his meal in a nearby
cave after seeing a beautiful girl in the distance. When he returned
months later, the mold (
Penicillium roqueforti) had transformed his
cheese into Roquefort.
Gorgonzola is one of the oldest known blue cheeses, having been
created around 879 AD, though it is said that it did not actually
contain blue veins until around the 11th century. Stilton is a
relatively new addition becoming popular sometime in the early
1700s. Many varieties of blue cheese that originated subsequently,
such as the 20th century
Danablu and Cambozola, were an attempt to
fill the demand for Roquefort-style cheeses that were prohibitive due
to either cost or politics.
In the United States of America, 100 g of generic[further
explanation needed] blue cheese contains the following nutritional
values according to the United States Department of
Fat: 28.74 grams
Carbohydrates: 2.34 grams
Fiber: 0 grams
Protein: 21.40 grams
Vitamin B12: 1.15 mg (50% of recommended daily intake)
Cambozola, a German variety of blue cheese
Similarly to other varieties of cheese, the process of making blue
cheese consists of six standard steps, as well as further additions
that give this blue-veined cheese its unique properties. The first
step is acidification where a starter culture is added to milk in
order to change lactose to lactic acid, thus changing the acidity of
the milk and turning it from liquid to solid. The next step is
coagulation, where rennet, a mixture of rennin and other material
found in the stomach lining of a calf is added to solidify the milk
further. Following this, thick curds are cut typically with a knife to
encourage the release of liquid or whey. The smaller the curds are
cut, the thicker and harder the resulting cheese will become. Salt is
then added to provide flavor as well as to act as a preservative so
the cheese does not spoil. Next, the cheese is given its form and
further pressed with weights if necessary to expel any excess liquid.
The final step is ripening the cheese by aging it. The temperature and
the level of humidity in the room where the cheese is aging is
monitored to ensure the cheese does not spoil or lose its optimal
flavor and texture.
Blue cheese undergoes the aforementioned steps with an added twist
that gives it its unique look of blue streaks found all throughout.
The blue veins are a result of adding the molds
Penicillium glaucum to the cheesemaking process, often introduced
after the curds have been ladled into containers in order to be
drained and formed into a full wheel of cheese. Although Penicillium
Penicillium glaucum are found naturally, cheese
producers nowadays use commercially manufactured Penicillium
roqueforti culture that have been freeze-dried, a form of dehydration
where water is evaporated from the frozen state without the transition
through the liquid state, to retain their value and are activated with
the addition of water. After the addition of the molds to the cheese,
the next significant step is needling, which is when the wheels of
blue cheese are pierced to create small openings to allow the air to
enter and feed the mold cultures, thus encouraging the formation of
The distinctive flavor and aroma of blue cheese arises from methyl
ketones (including 2-pentanone, 2-heptanone, and 2-nonanone) which are
a metabolic product of
Penicillium roqueforti. These compounds are
not formed in other types of cheese fermented by bacterial
In the European Union, many blue cheeses, such as Cabrales, Danablu,
Blue Stilton, carry a protected designation
of origin, meaning they can bear the name only if they have been made
in a particular region. Similarly, individual countries have
protections of their own such as France's Appellation d'Origine
Contrôlée and Italy's Denominazione di Origine Protetta. Blue
cheeses with no protected origin name are designated simply "blue
The main structure of the blue cheese comes from the aggregation of
the casein. In milk, casein does not aggregate because of the outer
layer of the particle, called the “hairy layer.” The hairy layer
consists of κ-casein, which are strings of polypeptides that extend
outward from the center of the casein micelle. The entanglement of
the hairy layer between casein micelles decreases the entropy of the
system because it constrains the micelles, preventing them from
Curds form, however, due to the function that the
enzyme, rennet, plays in removing the hairy layer in the casein
Rennet is an enzyme that cleaves the κ-casein off the casein
micelle, thus removing the strain that occurs when the hairy layer
entangles. The casein micelles are then able to aggregate together
when they collide with each other, forming the curds that can then be
made into blue cheese.
Penicillium roqueforti and
Penicillium glaucum are both molds that
require the presence of oxygen to grow. Therefore, initial
fermentation of the cheese is done by lactic acid bacteria. The lactic
acid bacteria, however, are killed by the low pH and the secondary
Penicillium roqueforti, take over and break the lactic
acid down, maintaining a pH in the aged cheese above 6.0. As the
pH rises again from the loss of lactic acid, the enzymes in the molds
responsible for lipolysis and proteolysis are more active and can
continue to ferment the cheese because they are optimal at a pH of
Penicillium roqueforti creates the characteristic blue veins in blue
cheese after the aged curds have been pierced, forming air tunnels in
the cheese. When given oxygen, the mold is able to grow along the
surface of the curd-air interface. In pressing the cheese, the
curds are not tightly packed in order to allow for air gaps between
them. After piercing, the mold can also grow in between the curds.
List of blue cheeses
^ Deetae P; Bonnarme P; Spinnler HE; Helinck S (October 2007).
"Production of volatile aroma compounds by bacterial strains isolated
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^ Fabricant, Florence (June 23, 1982). "Blue-veined Cheeses : The
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^ "Something is rotten in Roquefort". Business Week. December 31,
^ "Gorgonzola, the cheese that lives". Italian Food Excellence.
Retrieved 7 August 2016.
^ "Castello® Gorgonzola". Castello. Retrieved 7 August 2016.
^ "History of Stilton". StiltonCheese.co.uk. Retrieved 7 August
^ "Food Composition Databases Show Foods -- Cheese, blue".
^ a b "What Makes
Cheese Blue?". The Spruce. Retrieved
^ "Methyl ketones : Butter". webexhibits.org.
^ Shukla, Anuj; Narayanan, Theyencheri; Zanchi, Drazen (2009).
"Structure of casein micelles and their complexation with tannins".
Soft Matter. 5: 2884. doi:10.1039/b903103k. Retrieved 17 December
^ Diezhandino; Fernandez; Gonzalez; McSweeney; Fresno (2015).
"Microbiological, physio-chemical and proteolytic changes in a Spanish
blue cheese during ripening (Valdeon cheese)". Food Chemistry. 168
(1): 134–141. doi:10.1016/j.foodchem.2014.07.039.
^ Gilliot; Jany; Poirier; Maillard; Debaets; Thierry; Coton; Coton
(2017). "Functional diversity within the
species". International Journal of Food Microbiology. 241 (1).
^ Fernandez-salguero (2004). "INTERNAL MOULD - RIPENED CHEESES:
CHARACTERISTICS, COMPOSITION AND PROTEOLYSIS OF THE MAIN EUROPEAN BLUE
VEIN VARIETIES". Italian Journal of Food Science. 16 (4).
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