Influence of sodium chloride and glucose on the aggregation behavior of heat-denatured ovalbumin investigated with a multiangle laser light scattering technique

Abstract

The molecular characteristics of ovalbumin aggregates formed by heating with NaCl and glucose were investigated with a multi-angle laser light scattering system. The presence of NaCl and glucose affected the formation and molecular structure of the aggregates. Specifically, glucose increased the denaturation temperature of ovalbumin due to thermal stabilization of the native state of ovalbumin, regardless of the content of added NaCl. The surface hydrophobicity of the aggregates was increased by the addition of NaCl, which induced the denaturation of ovalbumin at a lower temperature. Aggregates with a larger weight-average molar mass (M(w)) and root mean square radius (R(g)) formed from heat-denatured ovalbumin with NaCl and glucose. The presence of NaCl during heat denaturation caused the formation of aggregates with a larger M(w) (1.9 x 10(5) and 3.5 x 10(6) g/mol for 0 and 10 mM NaCl, respectively) and R(g) (14.8 and 80.4 nm for 0 and 10 mM NaCl, respectively). Over a certain amount of NaCl, the addition of more glucose resulted in the formation of more aggregates with greater M(w) and R(g) values. In sum, the thermostability of ovalbumin was affected primarily by glucose, but the molecular characteristics of the soluble aggregates formed by heat denaturation varied primarily with NaCl content.