If adequate power levels and exposure
times were applied, complete homogenisation could be
obtained. Therefore, it can be concluded that ultrasound
treatment at high power levels may be used to reduce fat
globule size. Schmidt (34) observed that ultrasonic
homogenisation of milk at 60 °C could reduce the
average fat globule size to 1 µm. Similar results were also
obtained in other studies (7,30,36).
Furthermore, the value of homogenisation efficiency
must be below 10% for a very efficient homogenisation
process (32). A value of homogenisation efficiency below
10% indicates that homogenisation was very efficient.
While the lowest homogenisation efficiency was obtained
at a power level of 20 for 5 min (13.51), the highest
homogenisation efficiency was obtained at a power level
of 100 for 10 min (3.22). These results support the
results obtained from microscopic analyses.