Effect of high intensity ultrasound on structure and foaming properties of pea protein isolate

The effects of high intensity ultrasound (HIUS, 20 kHz, at varying amplitude 30%, 60%, 90% for 30 min) on structure and foaming properties of pea protein isolate (PPI) were investigated. No significant change was observed from the electrophoresis profiles and circular dichroism (CD) spectrum. Analyses of fluorescence spectroscopy and the amount of free sulfhydryl groups showed that HIUS induced protein molecular partial unfolding. Furthermore, HIUS decreased particle size of PPI and increased exposed hydrophobicity, resulting in a reduction of the surface tension at the air-water interface. Therefore, the foaming ability of PPI increased from 145.6% to 200.0%. The foaming stability increased from 58.0% to 73.3% with the increasing amplitude after 10 min though all reduced to 50.0% with the extension of time. That suggested that HIUS treatment has a potential to be implemented to modify foaming properties of PPI.