Size distribution of casein micelles during milk coagulation

Electron microscopy was employed to study the size distribution and the surface to volume ratios of casein micelles in coagulum from raw milk, heated milk and milk enriched with calcium chloride before the heating process. The particles size distribution of milk protein was changed by heating resulting in an increase in the free subunits of smaller size and the surface to volume ratios. On the other hand the clotting time was prolonged. Depression in the clotting time and surface to volume ratios was occurred by adding calcium chloride to the milk before the heating process to retard the formation of complex between the whey protein and milk casein.