Characterization of chitosan-based composite films with essential oil microcapsules and application for chilled beef preservation

Properties of ZSEO/CA microcapsules with different BW/SBO ratios were evaluated. • Chitosan-based films incorporated with essential oil microcapsules were fabricated. • Composite films performed the enhanced hydrophobicity and antimicrobial activity. • The composite films remarkably prolonged the shelf life of chilled beef for 12 d. This study developed an active composite film using chitosan (CS) as the matrix loaded with essential oil microcapsules. The physicochemical properties of essential oil microcapsules encapsulated with different beeswax/soybean oil (BW/SBO) ratios, along with the effects of their addition levels on the properties of composite films and effectiveness in preserving chilled beef were evaluated. The Zanthoxylum schinifolium essential oil/cinnamaldehyde (ZSEO/CA) loaded microcapsules formed by bacterial cellulose nanofibrils/whey protein isolate (BCNFs/WPI) complexes were successfully fabricated via spray drying, and their performance was adjusted by the composition of the encapsulated oil phase. Among them, the microcapsules fabricated at a BW/SBO ratio of 1:5 exhibited optimal comprehensive performance, yielding the lowest moisture content (4.85%), smallest powder size (6.7 μm) and good flowability. After incorporating the microcapsules into films, the obtained composite films significantly reduced water vapor permeability (WVP) to 0.77 g mm/m 2 •h•kPa and water solubility (WS) to 41.46%, and enhanced antimicrobial activity (inhibition zone diameter: 0.79-0.82 cm). Preservation experiments demonstrated that the composite films effectively extended the shelf life of chilled beef from 6 days to 12 days under 4 °C refrigeration. This research provided some guidance for the development of active food packaging films and application for chilled beef preservation.