Effect of homogenization conditions on properties of gelatin–olive oil composite films Original Research Article

Gelatin–olive oil composite films were prepared through emulsification to improve water barrier ability of gelatin-based films. The effects of homogenization conditions of film-forming dispersions (FFD) on lipid droplets distributions in the FFD and films were evaluated and compared. Some selected physical properties, e.g., water vapor permeability (WVP), microstructure of the films were also evaluated. The rotor–stator homogenizer provided a lower energy input and so the largest particles were observed in the related FFD and films. These films exhibited excellent water barrier ability, but poor mechanical resistance, extensibility and transparency. The microfluidizer provided the FFD with lower and narrower particle size distributions, promoting mechanical resistance, extensibility and transparency of the films. The physical properties of the emulsified films were dependent on the special microfluidization pressure or cycle used, e.g., the WVP of the films decreased upon increasing microfluidization pressure or cycle. The present results indicated that the microfluidizer can be used to modulate lipid droplets in the FFD, thus films’ properties.