Effect of radiofrequency processing on the structural and bio-functional properties of egg white proteins

Abstract

Radiofrequency (RF) assisted thermal processing can significantly enhance the gel firmness of egg white powder compared to the traditional hot room (HR) processing. Thus, the present study aims to delineate the impact of RF processing on the proteins' structure and bio-functional properties of egg white protein gels. The secondary protein conformations of egg white proteins exhibited no significant alteration upon RF-assisted thermal processing over traditional HR processing. In-vitro gastrointestinal (GI) digestion of egg white gels demonstrated that the RF processing did not compromise the accessibility of digestive proteases despite a more robust gel network. Peptides from the GI digest of egg white gel showed that Ovalbumin and Ovotransferrin were the parent proteins of most of the unique peptides generated, and minor structural differences accounted for these peptides. The bioavailability of the egg protein-derived peptides remains unaffected after RF processing without compromising the viability and integrity of the GI epithelial cells.

Keywords: Bioaccessibility; Bioavailability; Egg white gel digesta; Secondary protein structure; Simulated gastrointestinal digestion; Structure-function relationship.