LAUSR

Introducing lysozyme (Lys) to dopamine-modified poly (γ-glutamic acid) (PGA-DA), the self-assembled colloidal nanoparticles (Lys/PGA-DA) were obtained through the electrostatic, hydrogen bonding and hydrophobic interactions. After mixing vigorously colloidal nanoparticles and white oil, o/w gel-like emulsion formed. The influences of ionic strength on the properties and emulsifying performances of colloidal nanoparticles and the activity of Lys in emulsions were investigated in detail. Scanning electron microscopy (SEM) characterization and rheological measurements demonstrated that emulsifying properties of colloidal nanoparticles were significantly improved with increasing salt concentration. Moreover, fluorescence and circular dichroism (CD) measurements showed that the addition of salt might induce conformational changes of Lys in colloidal nanoparticles resulting in a more ordered secondary structure, thereby leading to an increase in enzyme activity. In vitro cytotoxicity of emulsions revealed that emulsions showed a low cytotoxicity and a high bioactivity. All results verified that the obtained emulsion could have potential application in food, pharmaceutical, and cosmetic fields. Graphical abstract Graphical abstract