Consequences of ball-milling treatment on the physicochemical, rheological and emulsifying properties of egg phosvitin

The emulsifying properties of phosvitin were stronger than those of other food proteins. In this study, phosvitin was subjected to ball-milling treatment for 20, 40 and 60 min, and the physicochemical, rheological and emulsifying properties were investigated. After the treatment, phosvitin possessed an unfolded and stretched structure, with a higher surface hydrophobicity and thermal stability. The morphology spectrum showed that the protein micelles tended to collapse into coarse particles with irregular and rigid structures. The rheological data illustrated that the treated phosvitin dispersion possessed an increased apparent viscosity. Correspondingly, the emulsifying ability of phosvitin was enhanced by 3.0, 2.9 and 2.5 folds for 20, 40 and 60 min of treatment, while the emulsifying stability decreased by 40.0%, 34.0% and 34.5%, respectively. These findings explored the relationship between structure and function of proteins in industrial processing, and indicated that ball-milling process could be applied to improve emulsifying properties of food proteins.