Influence of high intensity ultrasound and calcium chelating agent on structural and physicochemical properties of casein micelles

Increasing both UST and DSP significantly increased non-micellar calcium concentration (from 238.4 to 327.2 mg/kg) and PSI (from 29.0 % to 44.1 %), while surface hydrophobicity decreased significantly (p < 0.0001). Dh decreased from 206.1 to 186.5 nm with increasing UST up to 10 min but increased with increasing DSP at all USTs (p < 0.0001). Increasing DSP led to a more negative ζ-potential, decreasing from -16.1 mV at 0 mM DSP to -20.4 mV at 10 mM DSP in the absence of sonication (p < 0.0001). DSP and UST showed no significant effect on viscosity. FTIR analysis indicated limited effects of the treatments on the secondary structure of caseins. Overall, the combination of ultrasound treatment and calcium chelation altered key physicochemical properties of micellar caseins, which may be explored in future studies to assess their impact on functional properties.