treatment time of 70 min and ultrasound treatment temperature of
25 C, the yield of rice bran oil was close to the yield of oil extracted
by hexane Soxhlet extraction. This result implied that compression
and rarefaction of the elastic mechanical vibration wave of
ultrasonic can drive the medium, so that the liquid pressure changes
and results from the large number of vacuum bubble. When the
bubbles burst and generate strong instantaneous pressure, named
as ‘‘cavitation effect”. Rice bran particles and cells were sheared
and crushed. This action was helpful for rice bran oil extraction, thus
to improve the rate of oil.