Gelatin films functionalized by lignocellulose nanocrystals-tannic acid stabilized Pickering emulsions: Influence of cinnamon essential oil.

The Pickering emulsions containing cinnamon essential oil (CEO) stabilized by lignocellulose nanocrystals-tannic acid (LCNC-TA) complexes were used to improve properties of gelatin film. The influences of various volume proportion mixed oil (sunflower oil/CEO 1:0, 5:1, 2:1 and 1:1) were investigated. Introducing CEO reduced the droplet size approximately from 57 to 30 μm, facilitating droplet distribution in film matrix. With increasing CEO proportion, the surface structure of emulsion films became uniform without micropores or cavities, showing good compatibility with film matrix during film-forming process. Furthermore, increasing CEO proportion improved tensile strength (TS, 3.75-4.61 MPa) and water vapor permeability (WVP, 9.16 × 10-12-7.61 × 10-12 g·cm-1s-1Pa-1) of emulsion films. Besides, the UV blocking, antioxidant and antibacterial properties of emulsion films improved as CEO proportion increased. Compared with the control gelatin film, the loss of CEO in emulsion films effectively decreased through pre-embedding approach by Pickering emulsion method.