Active nano-micelle food packaging films with dual-barrier properties: film structure, essential oil sustained release and fruits preservation.

Active packaging films containing directly incorporated essential oils are often limited by poor dispersion, rapid and uncontrolled release, and deterioration of mechanical properties. To address these limitations, this study developed a sustained-release active packaging film based on nano-micelle-loaded fir essential oil (FEO), aiming to achieve stable loading and continuous release of FEO while simultaneously improving the structural integrity of the film. Film morphology, intermolecular interactions, mechanical and barrier properties, release behavior, antimicrobial activity, and fruit-preservation performance were systematically evaluated. Nano-micelle encapsulation improved FEO dispersion and compatibility with the polymer matrix, while hydrogen bonding and chain entanglement reduced phase separation. The optimized film exhibited a tensile strength of 60.35 MPa, an elongation at break of 38.06%, and a water vapor permeability of 6.81 × 10-11 g m-1 s-1 Pa-1. Moreover, the nano-micelles and polymer matrix formed a dual mass-transfer barrier, enabling sustained FEO release and prolonged antimicrobial activity. The films also delayed quality deterioration of citrus fruits and cherry tomatoes. This nano-micelle strategy simultaneously enhanced essential-oil stability, film performance, and sustained bioactive release, showing strong potential for long-acting bio-based food packaging.