EFFECT OF SUCROSE AND HIGH PRESSURE PROCESSING ON FUNCTIONAL AND PHYCISOCHEMICAL PROPERTIES OF EGG WHITE PROTEINS

Egg white is widely used in food applications because of its nutritional benefits and versatile functionalities. Traditional treatment like thermal pasteurization utilized for safety concern is disadvantageous to the egg white proteins due to the functionality impairment. High pressure processing (HPP) technology is known as a non-thermal food preserving method that can be operated at ambient temperatures. Sucrose is an essential ingredient that affects the functional behavior of egg white in numerous baking and pastry applications. The current study investigated the effect of sucrose and HPP on the functional and physicochemical properties of egg white proteins and verified the efficacy of HPP on microbial inactivation in egg white. Sucrose addition and HPP treatment were combined to study the foaming and physicochemical properties. Homogenized egg white samples were treated at selected HPP conditions (300-500 MPa) for 5-15 min, with an initial temperature of 4°C. Sucrose was added at 0-48% (w/v) to samples before or after HPP treatment. Foaming properties including foaming capacity and foam stability were measured immediately after whipping process. Turbidity and viscosity analyses were conducted within 24 hr after HPP treatment. The efficacy of HPP (500 MPa for 5 min) on microbial inactivation was verified using a pathogenic strain Salmonella enterica serotype Enteritidis (H7037) isolated from egg yolk implicated in a salmonellosis outbreak and a nonpathogenic Escherichia coli K12 strain (ATCC23716). All trials were completed in triplicate. Both addition of sucrose and HPP treatment decreased the foaming capacity but increased the foam stability of egg white proteins. Adding sucrose before HPP protected protein from turbidity and maintained foaming capacity, while adding sucrose after HPP greatly improved foam stability (p0.05). A 5-log reduction of both strains was achieved after HPP treatment at 500 MPa for 5 min. These results exhibited that HPP can be used as a processing technology for the egg white safety control and that HPP could modify egg white foaming quality in food baking applications.M.S. in Food Safety and Technology, May 201