Effects of ultra-high pressure homogenization on the properties and structure of interfacial protein layer in whey protein-stabilized emulsion

The effect of high pressure homogenization on the properties of whey protein adsorbed on emulsion interface was determined by competitive adsorption with Tween 20, Fourier transform infrared (FT-IR) spectroscopy, and RP-HPLC. The amount of whey proteins desorbed by Tween 20 increased at higher pressure. The results of FT-IR spectroscopy showed that higher homogenization pressures led to decrease of α-helix and increase of β-sheet indicating the formation of fewer interactions with the lipid phase and more interaction between adsorbed whey proteins, respectively. In RP-HPLC profile, the retention time of whey protein desorbed from high pressured emulsion was shorter than that from low-pressured emulsion. From these results, we have shown that higher pressures cause the formation of a more compact interfacial protein layer. Finally, “high pressure” emulsions are more stable than “low-pressure” ones, because of the protein layer formed by protein-protein interactions as well as the decrease of droplet size.