(E,E)-2,4-decadienal improved the stability of gelatin emulsion manufactured by low-energy stirring emulsification

The study investigated the impact of varying concentrations of ( E,E )-2,4-decadienal (DDE; 0, 9, 27, 54, and 81 μg/mL) on the stability of gelatin emulsions prepared via a low-energy stirring emulsification method, which relies solely on simple mechanical stirring. As the concentration of DDE increased, the emulsifying activity index, emulsion stability index, and viscosity of emulsions first increased significantly ( P  < 0.05) and then decreased significantly ( P  < 0.05), indicating that the emulsion stability first improved and then decreased. The highest emulsion stability was observed at a DDE concentration of 27 μg/mL, as evidenced by the highest adsorbed protein content (84.78 %) and the maximum absolute zeta potential value (14.46 mV). These findings suggested that DDE, in combination with low-energy stirring emulsification, improved the stability of gelatin emulsions. The results of protein structure indicated that DDE enhanced the depolymerization of gelatin by disrupting hydrophobic interactions within gelatin aggregates, leading to the exposure of hydrophobic groups on the protein surface. This exposure enhanced the adsorption of gelatin at the oil-water interface, thereby improving the emulsion stability through increased steric hindrance at the interface. Furthermore, DDE reduced the surface tension of soybean oil, contributing to further stabilization of the interface.