Effects of High Intensity Ultrasound Frequency and High‐Speed Agitation on Fat Crystallization

Abstract

The objective of this research was to examine the effect of ultrasound frequency and high‐speed agitation on lipid crystallization. Interesterified soybean oil was crystallized at 44 °C without and with the application of high intensity ultrasound (HIU—20 and 40 kHz) or with high‐speed agitation (6000 and 24,000 rpm). Two tip amplitudes (24 and 108 µm) and three pulse durations were evaluated (5, 10, and 15 s) for the acoustic frequencies tested. Sonication at 20 kHz of frequency significantly reduced crystal size, increased (p < 0.05) elasticity (435.9 ± 173.3–80,218 ± 15,384 Pa) and SFC (0.2 ± 0.0–4.5 ± 0.4%). No significant difference was observed in the crystallization behavior of these samples when sonicated at different amplitudes for 5 and 10 s. The crystallization behavior was significantly delayed (p < 0.05) in samples sonicated using 108 µm amplitude for 15 s. Larger crystals were formed in samples sonicated at 40 kHz compared to those obtained with 20 kHz and lower SFC (3.7 ± 0.0%) and elasticity (3943 ± 1459 Pa) values were obtained. High‐speed agitation at 24,000 rpm increased SFC (5.5 ± 0.1%) and crystallized area and decreased the elasticity (42,602 ± 11,775 Pa) compared to the samples sonicated at 20 kHz.

Use of High‐Intensity Ultrasound to Change the Physical Properties of Oleogels and Emulsion Gels

“…These studies showed that higher power levels have a greater effect on the induction of crystallization and on the reduction of crystal size. However, similar results to the ones reported in our study where a lack of effect of power level was reported by Silva et al (). It is possible that the lack of effect of the power level is due to the high melting point of the sonicated material, which is a common property of Silva's and our work.…”

Tailoring Crystalline Structure Using High‐Intensity Ultrasound to Reduce Oil Migration in a Low Saturated Fat

“…). Similar results on the effect of sonication on crystals sizes were observed in IESBO (Lee et al, ; Silva et al, ; Ye et al, ) and palm oil (Chen et al, ; Ye and Martini ).…”

Exploitation of high‐intensity ultrasound to modify the structure of olive oil organogel containing propolis wax

“…Crystallization can be modulated by external forces such as shear and cooling rate since they affect nucleation and crystallization kinetics (Blake & Marangoni, 2015). Recently, high-intensity ultrasound (HIU) with frequencies between 20 and 100 kHz has been introduced as a promising technique to modify microstructure of fat crystals (Silva et al, 2017). This technique could affect both primary and secondary nucleation of crystallization due to a phenomenon, called cavitation.…”