Casein hydration and fat emulsification during manufacture of imitation cheese, and effects of emulsifying salts reduction

The manufacture of imitation cheese in a Farinograph was interrupted at various times, and the casein matrix formed and the free liquid were collected and analysed. During manufacture, a torque profile was generated, which showed three distinctive stages; an initial torque peak “peak-1”, followed by a trough and finally a second “peak-2”. Analyses provided quantitative and qualitative evidence that the initial manufacturing stage (peak-1) was concerned with water uptake and the formation of a hydrated casein matrix, as ∼75% of the added water was absorbed. This was followed by a fat emulsification phase (trough) and, once sufficiently emulsified, by the incorporation of the fat to form a homogeneous cheese mass, at peak-2. A similar approach showed that the effect of emulsifying salts reduction was to retard casein hydration, reflected in an increase in peak-1 torque, and led to a prolonged mixing time to sufficiently emulsify fat and allow its incorporation.