Mechanism of effect of heating temperature on functional characteristics of thick egg white

Abstract

Egg white is often used in various food products because of its good functional properties such as gelling, foaming and emulsifying. In this article, heat treatment（30, 40, 50, 60 °C, 10 min）was employed to investigate the effects on the functional, physicochemical and molecular properties of thick egg white (KEW) comprehensively. The heat treatment caused the hardness, springiness, viscosity, and particle size of KEW to decrease and then increase. According to the results of surface hydrophobicity, sulfhydryl content and fluorescence spectroscopy, the protein structure expanded and then further aggregated after heat treatment with the exposure of the reactive group. The solubility, foaming capacity and emulsifying capacity of KEW were improved by heat treatment. The result of Fourier transformed infrared spectroscopy (FT-IR) showed that the heat treatment changed the structure of KEW from ordered to disordered. The heat treatment did not change the protein composition of KEW based on SDS-PAGE.