Comparison of batch and continuous ultrasonic emulsification processes

Abstract

a b s t r a c tBatch and continuous ultrasonic emulsification processes on both lab and pilot scales were investigated using Tween 80 or milk protein isolate (MPI) as emulsifiers. The process parameters of processing volume, residence time and ultrasonic amplitude, as well as emulsion formulations, emulsifier type and concentration, were studied for the effect on emulsion droplet size. Emulsions prepared with ultrasound yielded submicron droplets, $200 nm, with Tween 80 and MPI, utilising all processing methodologies. Inverse power laws were obtained correlating emulsion droplet size with respect to energy density, highlighting the efficiency of the continuous over batch processing. This efficiency is ascribed to the smaller processing volumes, associated with continuous ultrasonic emulsification. Longer processing times were required for MPI to achieve submicron droplets (<200 nm) in comparison to Tween 80 as greater times are necessary for interfacial adsorption and surface stabilisation, shown by interfacial tension measurements.

Preparation and characterization of rice bran protein‐stabilized emulsion by using ultrasound homogenization

“…However, an alternative method is the use of ultrasound, which allows the preparation of colloidal emulsions with good physical properties as well as low-cost processes (Higuera-Barraza et al, 2017). The ultrasound homogenization is largely based on the use of sound waves of different frequencies of energy, which can readily produce submicron droplets (O'Sullivan, Murray, Flynn, & Norton, 2015). McCarthy et al (2016) prepared emulsion by ultrasound at the amplitude of 266 W and frequency of 20 kHz, and their results indicated ultrasound can produce emulsion with smaller sized droplets.…”

Characterisation of flow behaviour and velocity induced by ultrasound using particle image velocimetry (PIV): Effect of fluid rheology, acoustic intensity and transducer tip size

“…Low frequency (≤100 kHz) high power (>10 W cm -2 ) ultrasound is a technology which has garnered significant interest over the past decade owing to its capacity to perform a multitude of processing applications [1], including dispersion [2], dissolution [3], molecular modifications [4,5], and emulsification [6,7]. Ultrasonic treatment of liquid media operates through the generation of numerous cavitation sites, arising due to pressure differentials during the propagation of an acoustic wave front through the liquid [8].…”

Ultrasonic and Heat Treatment of Crude Oils

“…The authors of similar works give data on the intensity of ultrasonic treatment of oil calculated for water [42,43]. However, as our calculations show, this approach is approximate.…”