Handbook of Food Science and Technology 3

Figure 1.21.
 Drainage and acidification kinetics
and processing types (according to [MIE 91]) 
The following Figures (1.22, 1.23, 1.24 and 1.25) give examples of 
processes associated with the production of acid curd (fresh cheese;
Figure 1.22), mixed curd with a predominantly acid nature (industrial 
Camembert; Figure 1.23), mixed curd with a predominantly rennet nature 
(Saint-Paulin; Figure 1.24) and rennet curd (Beaufort; Figure 1.25).
Decoupling of drainage and acidification kinetics 
It is possible to completely decouple drainage and acidification kinetics by 
concentrating milk proteins and fat by means of cross-flow filtration. 
Ultrafiltration (see Chapter 6, Volume 2) can concentrate all the milk proteins,

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From Milk to Dairy Products 49 
whereas 0.1 µm microfiltration results in the total retention of caseins and
the transmission of whey proteins to the permeate (transmission rate
between 60 and 80%); as a result, 0.1 µm microfiltration is mainly carried out 
when the cheese manufacturer also looks for a high-quality permeate, which in 
this case is a “true whey” (absence of phospholipids, casein fines and any 
particles).
Figure 1.22.
 Manufacturing process of fresh cheese 

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50 Handbook of Food Science and Technology 3 
Figure 1.23.
 Manufacturing process
of industrial Camembert

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From Milk to Dairy Products 51 
Figure 1.24.
 Manufacturing process of Saint Paulin 

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52 Handbook of Food Science and Technology 3 
Figure 1.25.
 Manufacturing process of Beaufort 
The ultrafiltration of milk results in a liquid pre-cheese, which has the 
composition of drained cheese [MAU 69]. This process eliminates drainage 
after coagulation and therefore allows, in some cases, molding directly into
the containers for retail; it reduces the weight difference due to molding of the 
curd, increases yield (by 10 – 20% through whey protein retention in the 
cheese) and decreases rennet consumption (added after filtration). It has, 
however, the disadvantage of yielding cheeses with high lactate and lactic acid 

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From Milk to Dairy Products 53 
contents, due to the high buffering capacity of pre-cheeses resulting from the 
concentration of calcium phosphate associated with casein. To overcome these 
problems, it is possible to pre-acidify and salt the milk to solubilize some of 
the colloidal calcium phosphates, which are then removed during 
ultrafiltration. This method is limited, however, since pre-acidified milk is 
thermally less stable and it is more difficult to add value to the permeate.
1.3.4.4.
 Ripening 
Ripening involves the enzymatic digestion of the protein and lipid 
components in the curd. It is a complex biochemical process for several 
reasons: 
– the cheese matrix resulting from the coagulation and drainage of milk has 
a very high level of physicochemical heterogeneity; 
– enzymes involved in ripening have several origins: they could be 
endogenous milk enzymes (plasmin, lipase, etc.), added to milk during 
manufacturing (coagulating enzymes, microorganisms) or produced during 
ripening by microbial synthesis (bacteria, yeasts, moulds).
The curd and biological agents constitute a complex ecosystem and a 
heterogeneous bioreactor, the parameters of which are not always well 
defined. Ripening is dominated by three major biochemical phenomena: 
– the fermentation of residual lactose and the degradation of lactate; 
– the hydrolysis of fat and proteins; 
– the production of aroma from fatty acids and amino acids.
These transformations give the cheese its characteristics; they modify its 
appearance, composition and consistency, while at the same time flavor, 
aroma and texture develop.