Fabrication and characterization of active gelatin-based films integrated with nanocellulose-stabilized Pickering emulsion containing Oliveria Decumbens Vent. essential oil

Abstract

Stabilizing essential oils (EOs) within biodegradable matrices to create homogeneous and stable films with desirable properties is challenging due to the hydrophobic nature of EOs, which hinders their uniform infusion into the matrix. In this study, we investigated the feasibility of creating active films made of gelatin, infused with nanocellulose-stabilized Pickering emulsion (PE) containing Oliveria Decumbens Vent. essential oil (OEO). The Pickering emulsion effectively stabilized the 50% v/v of OEO, which was subsequently incorporated into a gelatin film at 0, 3, 5, 7, and 9% v/v, to produce active films. FTIR data showed that the OEO-PE was physically trapped in the film matrix through hydrogen bonds, which was also verified by SEM micrographs. The addition of OEO-PE notably changed the films' mechanical properties, leading to reduced tensile strength and enhanced elongation (P < 0.05) with no significant impact on their water vapor permeability. The incorporation of OEO endowed the film matrix with high antioxidant and antibacterial activity against E. coli and S. aureus. Thermal analysis using differential scanning calorimetry showed a 36–171 °C endothermic peak in all films, due to water evaporation and melting. The gelatin film containing 9% OEO-PE exhibited superior physical properties, enhanced water resistance, and excellent antibacterial and antioxidant activity.