Dynamic visualization and microstructure of syneresis of cheese curd during mechanical treatment

A setup for dynamic visualization of syneresis of cheese curd during mechanical treatment was developed that enabled the shrinkage of a single grain of curd to be monitored. Under quiescent conditions, increasing the temperature from 32 °C to 40 °C greatly increased the degree of curd shrinkage. Applying a controlled deformation at constant force resulted in a more rapid and extensive syneresis. Changing the interval between compressions and examining curd grain microstructure by transmission electron microscopy demonstrated a relationship between compression frequency, resultant morphology of para-casein clusters and curd shrinkage. A compression interval of 10 min provided the least rearrangements and resulted in formation of loose clusters and a low rate of shrinkage. A 5 min compression interval favoured straightening of network strands and facilitated moisture expulsion, whereas a 2.5 min interval seemed to break network strands, leading to dense and branched protein clusters with an accompanying decrease in syneresis.