Glycosylation of egg white protein with maltodextrin in the dry state: Changes in structural and gel properties

Abstract

The glycosylation of egg white proteins (EWP) with maltodextrin (MD) was investigated by monitoring their gel properties and protein structure. The improved gel properties of glycosylated EWP (GEWP) were confirmed by the increase in gel hardness, gel water holding capacity (WHC), rheological parameters, and finer gel microstructures. The protein structures were characterized by monitoring changes in the content of sulfhydryl (SH) group, circular dichroism (CD) and X-ray diffraction (XRD) spectra, and differential scanning calorimetry (DSC). The GEWP structures were unfolded due to extended glycosylation, as observed by increased content of exposed SH group and β-sheet and decreased crystallinity, thermal denaturation temperature (T_d), and enthalpy (ΔH). A correlation was also found between the gel properties and the protein structural changes. Overall, this study is beneficial for determining the mechanism of glycosylation and provides a convenient approach to improving the gel properties of EWP, which can further broaden the application of EWP in the food industry.

Keywords: Circular dichroism; Differential scanning calorimetry; Maillard reaction; Scanning electron microscopy; X-ray diffraction.