The Effect of Hydration on the Thermal Stability of Ovalbumin as Measured by Means of Differential Scanning Calorimetry

Abstract

The thermal denaturation of ovalbumin (egg albumin) was investigated by means of differential scanning calorimetry in the water-content range from 0.11 to 1.15 g of water per g of protein. At water contents above 0.76 g/g, the temperature, Td, and the enthalpy, ΔHd, of denaturation were scarcely dependent at all on the water content. At lower water contents, however, both Td and ΔHd showed a marked dependence on the water content. The degree of the hydration dependence of the Td and ΔHd suggested that the amount of water required to hydrate ovalbumin was 0.76 g/g and that at least two types of the hydration phase contributed to the thermal stability of the protein.