IN-SITU OBSERVATION OF RENNETTING BY ELECTROACOUSTICS

The new technique of electroacoustics has been used to observe the ren netting of skim milk without the necessity of dilution. The observed d ecrease in the zeta potential of the casein micelles is in very good a greement with literature reports and confirms that the primary stage o f rennetting is being observed. There is a large initial decrease in t he apparent size of the micelles which does not agree with other obser vations. This suggests that electroacoustics probes a different change in the micelle properties, perhaps an increase in porosity. In the se condary stage the zeta potential does not change much and the apparent particle size increases.