USE OF AGITATION, HOMOGENIZATION AND COLLOID MILLING TO MINIMIZE HEAVY COAGULUM FORMATION IN LACTIC CASEIN MANUFACTURE

Several methods were investigated for minimising heavy coagulum format ion in lactic casein manufacture. Agitation during coagulation could e ither increase or decrease heavy coagulum formation depending on the t iming and geometry of agitation. Agitation during coagulation reduced setting times probably because clumped starter cells were maintained i n suspension where acid production was faster. Homogenising skim milk at 230 bar before starter inoculation had no significant effect on hea vy coagulum formation. However, lower pressure homogenisation or collo id milling during incubation at any pH below 6.6 were both successful in virtually eliminating heavy coagulum formation, presumably because clumps of cells were broken up and thus prevented from settling. Highe r incubation temperatures, e.g. 30 degrees C, increased heavy coagulum formation. Separation of skim milk from whole milk at 5 degrees C did not reduce heavy coagulum formation compared to separation at 55 degr ees C.