Structurally robust chitosan-based active packaging film by Pickering emulsion containing tree essential oil for pork preservation.

The unstable structure of Pickering emulsion caused the fast release of active substance from active packaging and failure food preservation. Herein, a novel in-situ condensation strategy was proposed to construct sustained released chitosan (CS)-based active packaging film, in which the soybean separation protein (SPI)-carboxymethyl cellulose (CMC) emulsion (SCCE) containing tea tree essential oil (TTO) was physically incorporated into CS matrix. Originating from the strong electrostatic interaction of negatively charged SPI-CMC emulsion and positively charged CS matrix, a robust shell was in-situ formed on the outermost layer and served as armor to boost the structural stability of emulsion. The optimized SCCE has a homogeneous texture even after long-term storage (14 day) and under extreme conditions (high and low temperature, strong acid and alkali environment). The lifespan of packaged pork can be effectively extended at least 6 days. Our findings provided a new perspective for structurally robust and sustained-release food packaging films.