Dairy Chemistry And Biochemistry

CHEMISTRY AND BIOCHEMISTRY OF CHEESE AND FERMENTED MILKS^419

The lack of definitive information on the key flavour-generating reactions

in cheese is hampering efforts to accelerate ripening, which are, at present,

empirical. Considerable in-depth information on the biochemistry of cheese

ripening is now becoming available which will facilitate the genetic engin-

eering of starter cultures with improved cheesemaking properties. Acceler-

ation of cheese ripening has been reviewed by Fox et al. (1996b).

10.3 Acid-coagulated cheeses

On acidification to pH 4.6, the caseins coagulate, which is the principle used

to manufacture of a family of cheeses which represent about 25% of total

cheese consumption and are the principal cheeses in some countries (Appen-

dix 10B). Acidification is traditionally and usually achieved by in situ

fermentation of lactose by a Lactococcus starter but direct acidification by

acid or acidogen (gluconic acid-b-lactone) is also practised. The principal

Quarg-type

-Skim milk Quarg

-Full lit Quarg

Fromage t'tais

Ldhneh

Lahanch

Fresh cliccse preparaiiiins

Crcam cheese-type

-douhle/singlc Crcnm cliccsc

-Petit Suisse

-Neufchatcl

Cottage cheese-type

-Bakers cliccsc

-TVWO~

-Low/lht Cotiagc chccse

Qucso Blanco

Ricotta

Mascarponc

Ricottonc

Brown 'cheese'

-Mysost

-Gudhrandsalosi

-Ek\r: Gcisoat

-Floieo~t

Figure 10.26 Examples of acid-coagulated or heat-acid coagulated or whey-based cheese
varieties (from Fox et d., 1996a).