Milk-and-Dairy-Products-in-Human-Nutrition-FAO

Chapter 3 – Milk and dairy product composition 79
respecting the principle that cheese-making results in a concentration of milk
protein (in particular, the casein portion), and that consequently, the protein
content of the cheese will be distinctly higher than the protein level of the blend
of the above milk materials from which the cheese was made; and/or
(b) processing techniques involving coagulation of the protein of milk and/or
products obtained from milk which give an end-product with similar physical,
chemical and organoleptic characteristics as the product defined under (a).”
The main step in cheese-making, the coagulation of the casein component, is
achieved using one of the following methods, or a combination of these methods:
a) limited proteolysis using enzymes; b) acidification by adding acids or a
starter culture; and c) acidification combined with heating to about 90 °C (Fox and
McSweeney, 2004; Henning et al., 2006). The majority of cheeses are produced by
enzymatic (rennet) coagulation; rennet from the stomachs of young calves, kids,
lambs and buffalo was traditionally used (Fox and McSweeney, 2004).
The coagulated milk, the curd, can be separated from the whey in several ways.
For Camembert (defined in CODEX as a “soft surface ripened, primarily mould
ripened cheese”), the curd is ladled into moulds and kept overnight while the whey
is slowly drained off; the moulds are turned regularly to allow the whey to drain.
In some other cheeses, the curd is cut into cubes while being heated, causing it to
float in the whey. The whey is drained off, while the curd is subjected to syneresis
(dehydration); this involves cutting the coagulum, cooking, stirring, pressing, salting
and other operations that promote gel syneresis (Fox and McSweeney, 2004).
The final stages are shaping (moulding and pressing) and salting, which contributes
to the dehydration process (about 2 kg of water is lost per kg of NaCl taken up)
(Fox and McSweeney, 2004).
Cheeses are also classified according to the post-coagulation operations they
have undergone (Table 3.9). The majority of rennet-coagulated cheeses are subjected
to ripening. According to the CODEX general standard for cheese (FAO and
WHO, 2010g):
“Ripened cheese is cheese which is not ready for consumption shortly after
manufacture but which must be held for such time, at such temperature, and
Table 3.9
CODEX designation of cheese according to firmness and ripening characteristics
According to firmness
MFFB%* Designation According to principal ripening
67 Soft In brine
* MFFB equals percentage moisture on a fat-free basis, i.e.
[Weight of moisture in the cheese/(Total weight of cheese – Weight of fat in the cheese)] × 100