Thermal aggregation of duck egg white solution (1 mg protein/ml, pH 7) was monitored in the presence
of different NaCl concentrations (0–6%, w/w) across the temperature range of 20–90 C. Duck egg white
solution exhibited higher turbidity with coincidental increases in surface hydrophobicity and decreases
in sulfhydryl group content as temperatures increased from 70 to 90 C (p < 0.05). As NaCl concentration
increased, the negative charge decreased, with coincidental increases in particle size of aggregate after
heating to 90 C. As visualised by confocal laser scanning microscopy, larger clusters of protein aggregates
were observed with increasing NaCl concentrations. Major duck egg white protein with molecular mass
of 45 kDa disappeared in the presence of 2–6% NaCl after heating above 80 C, regardless of concentrations.
Therefore, NaCl, especially at high concentrations, could induce thermal aggregation of duck egg
white protein, which could determine the characteristics of salted egg white after heating