Structural characterization and functional properties of egg white protein treated by electron beam irradiation. (March 2023)

• Record Type: Journal Article
• Authors: Liu, Yun; Huang, Mengling; Liu, Xiazhong; Hu, Mingyang
• Is Part Of: Innovative food science & emerging technologies. Volume 84(2023)
• Publication Date: 2023-03
• Subjects: Egg white protein (EWP) -- electron beam irradiation (EBI) -- Functional properties -- Structural characteristics -- Intermolecular forces; Food -- Biotechnology -- Periodicals; Food industry and trade -- Technological innovations -- Periodicals; Aliments -- Biotechnologie -- Périodiques; Food -- Biotechnology; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.ifset.2022.103262
• Languages: English
• ISSNs: 1466-8564

Abstract

Abstract: This study investigated the functional properties and structural characteristics of egg white protein (EWP) powder treated by electron beam irradiation (EBI) at the doses of 5, 10, 20, 30, 50, 70 and 100 kGy. In comparison with the untreated sample (0 kGy), the EBI-induced EWP showed generally better solubility and higher antioxidant capacity by ABTS + radical scavenging assay. Furthermore, the emulsifying activity index of EBI-induced EWP increased with increased EBI dose, reaching the maximum value of 15.8 ± 0.4 m 2 /g at 100 kGy. The emulsifying stability index and ϛ-potential of EBI-induced EWP showed fluctuating tendencies. These functional property changes of protein were attributed to the conformational changes caused by EBI. SDS-PAGE patterns confirmed that high-dose EBI would result in protein depolymerization to low-mass molecules at 11 kDa, contributing to the increased solubility. Circular dichroism data demonstrated that EBI-induced EWP exhibited partial denaturation and a flexible structure, which was responsible for the improved emulsifying properties. Fluorescence spectra revealed that high EBI doses led to an increase in the polar environment around tryptophan, which could enhance the solubility and antioxidant activity of EWP. In addition, high EBI doses decreased the content of free and total sulphydryl groups, and changed the intermolecular forces of protein, including ionic bonds, hydrogen bonds, hydrophobic interactions, and disulfide bonds. These findings can provide solid support for practical applications of EBI technology in EWP food processing. Highlights: The EBI-induced EWP showed better solubility and higher antioxidant capacity. The emulsifying properties of EWP were changed before and after EBI treatment. The conformation changes of EBI-treated EWP were responsible for the improved functional properties. The relationship between structure and functional properties of EWP was elucidated. The mechanism of EWP conformation changes was demonstrated through intermolecular forces.