Liposomal vesicles-protein interaction: Influences of iron liposomes on emulsifying properties of whey protein

Abstract In this study, whey protein (WP) was used as a model protein to interact with ferrous sulfate liposomes (FL). The interaction between FL and WP was researched using circular dichroism, intrinsic fluorescence, surface hydrophobicity, free sulphydryl groups, Fourier transform infrared spectroscopy, zeta potential, particle size, and interfacial tension. These observations indicated that FL interacted with WP via electrostatic force, hydrophobic force, and hydrogen bonds. WP secondary structure and tertiary structure could be changed by the interaction between FL and WP. The emulsifying properties of WP were improved by the interaction between FL and WP. Emulsifying activity index and emulsifying stability index of WP in the presence of FL increased from 39.69 to 65.63 m 2 /g, from 28.63 to 101.55 min, respectively. And the WP-stabilized emulsion droplet size decreased from 1.64 μm to 0.78 μm in the presence of FL. However, the emulsifying properties of WP were also influenced by liposomal composition, pH, and temperature. The changes of WP emulsifying properties could be attributed to the effects of liposomes on WP secondary structure and tertiary structure, zeta potentials, and particle size. This work provides new insights into the application of liposomes in food.