Influence of calcium and sodium chloride on caseinomacropeptide self-assembly and flow behaviour at neutral pH.

Abstract The effect of adding NaCl or CaCl 2 on particle size distribution and flow behaviour of caseinomacropeptide (CMP) aqueous solutions was investigated over a wide range of concentrations (0–200 mmol L−1), temperatures (5–60 °C) and during 14 days of storage. In the absence of salts, CMP mainly presented a monomeric form at pH 7.0. If sodium or calcium chloride is added, hydrophobic associations of CMP is promoted due to screening of electric charges. Calcium chloride had a bigger impact than NaCl. Indeed, small variations in CaCl 2 concentration induced major changes in size distributions and increased the viscosity and the cloudiness of CMP solutions upon storage. The largest aggregates and highest viscosities were obtained at concentrated regime (CMP concentration > 8 g/100 g), high CaCl 2 concentration (>1.2 mmol g−1 CMP) and upon storage. Highlights • Sodium and calcium chloride caused attractive interactions between CMP monomers at pH 7.0. • CMP self-assembly had a cation specific effect; calcium ions had a biggest influence. • CMP solutions allowed the incorporation of large amounts of CaCl 2. • Viscosity of CMP-salt solutions decreased with increasing temperature. • Viscosity of CMP-CaCl 2 solutions can be enhanced by storage. [ABSTRACT FROM AUTHOR]