The Effect of Ionic Strength on the Formation and Stability of Ovalbumin–Xanthan Gum Complex Emulsions

Abstract

Protein–polysaccharide complexes have been widely used to stabilize emulsions, but the effect of NaCl on ovalbumin–xanthan gum (OVA-XG) complex emulsions is unclear. Therefore, OVA-XG complex emulsions with different XG concentrations at pH 5.5 were prepared, and the effects of NaCl on them were explored. The results indicated that the NaCl significantly affected the interaction force between OVA-XG complexes. The NaCl improved the adsorption of proteins at the oil–water interface and significantly enhanced emulsion stability, and the droplet size and zeta potential of the emulsion gradually decreased with increasing NaCl concentrations (0–0.08 M). In particular, 0.08 M NaCl was added to the OVA-0.2% XG emulsion, which had a minimum droplet size of 18.3 μm. Additionally, XG as a stabilizer could improve the stability of the emulsions, and the OVA-0.3% XG emulsion also exhibited good stability, even without NaCl. This study further revealed the effects of NaCl on emulsions, which has positive implications for the application of egg white proteins in food processing.

Keywords

• ionic strength
• stability of emulsions
• ovalbumin
• Xanthan gum