Skip to main content
2023 AOCS Annual Meeting & Expo Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Back
Video

Edible Applications Technology

Session:: Fat Crystallization - Part II

Acoustic cavitation in lipids: bubble dynamics and fat crystallization

Tuesday, May 2, 2023
11:20 AM – 11:40 AM MDT
Room: 201
Abstract: Lipid sonocrystallization has been a topic of study for the past 15 years; however, the underlying mechanisms that drive the observed enhanced crystallization kinetics of these lipids is still to be accurately determined. This presentation will summarize recent research by our research group that explores acoustic cavitation events in fats and oils.
Cavitation events in lipids were evaluated by a combination of techniques including high-speed imaging, acoustic emissions, and laser scattering. The high-speed imaging allowed us to characterize cavitation events in an oil, which were further monitored using a hydrophone and laser scattering. The hydrophone was able to detect acoustic activity of the oscillating and collapsing bubbles (or clusters of bubbles); while the laser allowed us to determine and corroborate the periodicity of these events. These experiments allowed us to characterize cavitation events that occur during sonication of lipids and in turn study the crystallization kinetics of the system.
Two main events were observed during sonication (~20 kHz, HIU) of lipids: first, a cluster of bubbles that oscillate very close to the ultrasonic horn and second, a streamer of bubbles that travel away from the horn at velocities of the order of 10 m s-1 . In this presentation we will show how the characteristics of the cavitation events change with acoustic power and with oil viscosity. For example, our research shows that the cluster of bubbles observed close to the tip of the ultrasonic horn, oscillates with specific subharmonics that change as the acoustic power alters. We also detected a bifurcated streamer (BiS) that was particularly effective at enhancing the crystallization in an all-purpose shortening. The duration of this BiS event during source ring-up was proportional to the viscosity of the oil. For example, shorter BiS lifetimes within the ring-up were observed at higher temperatures (lower viscosities).