Dairy Ingredients for Food Processing

Figure 11.7. Changes in the microstructure of process cheese during manufacture. Adapted from Metzger
(2004).

Emulsifying Salts

(disodium phosphate)

Calcium-phosphate cross-linked Caseins present in natural cheese and other dairy ingredients: The cross-linking prevent

the mobility of the casein molecules and hence they cannot interact with water or fat

Calcium phosphate

Fat Phase

Caseins

The sodium ions furnished by

the emulsifying salts displace

the calcium ions from the

calcium-phosphate cross-links

thereby breaking the cross-links

and increasing the mobility of

casein, the caseins are now

flexible and can interact with

water and fat phases

Heat and Mixing induce

interactions between the

hydrated caseins and fat,

consequently the caseins

emulsify the fat to form a

molten process cheese

emulsion.

Gel formation during cooling:

Re-formed gel network of

hydrated and emulsified caseins

Phosphate Group

Sodium ions

303