Effect of oxidation induced by hydroxyl radical‐mediated model on molecular structural and physical character of egg white powder

Abstract

Summary The objective of this study was to determine structure and functional properties changes of oxidised egg white protein derived from hydrogen peroxide (H 2 O 2 )/ferric chloride (FeCl 3 ) /ascorbic acid hydroxyl radical‐generating systems at room temperature, including carbonyls, sulfhydryl and total sulfhydryl groups, dityrosine, free amino, surface hydrophobicity, particle size distribution, intermolecular forces, and foamability and emulsibility. Protein carbonyl and dityrosine content of egg white protein were increased ( P < 0.05) with increasing the concentrations of H 2 O 2 . Oxidation decreased free sulfhydryl, total sulfhydryl groups and surface of hydrophobicity comparing with nonoxidised egg white protein. Oxidation also reduced its free amino content ( P < 0.05). The low concentration of H 2 O 2 contributing the average particle size of egg white protein was smaller than the control group. However, the high concentrations of H 2 O 2 caused that egg white protein aggregated and the average particle size became larger. To sum up, oxidation made EWP denaturation and aggregation.