Starch-based controlled release packaging films for fruit preservation via clove oil loaded in modified MOF(Zr)

The controlled release of volatile antimicrobials from biodegradable food contact materials is an effective strategy for active fruit packaging. In this study, glycidyl methacrylate (GMA)-modified NH2-UiO-66 was developed as a porous carrier for clove oil (CEO), achieving a high loading capacity of 780.3 ± 6.5 mg/g. CEO@GMA-NH2-UiO-66 was incorporated into starch/gellan gum films at varying concentrations (0.5–4 wt% based on the combined mass of starch and gellan gum). Structural characterization confirmed successful GMA functionalization, CEO encapsulation, GMA-NH2-UiO-66 stability, and good integration of the active filler within the starch matrix. The composite film containing 2 wt% CEO@GMA-NH2-UiO-66 exhibited optimal performance, with tensile strength of 23.8 ± 0.9 MPa, elastic modulus of 315.3 ± 15.9 MPa, and oxygen transmission rate of 30.7 ± 1.36 g·d⁻1·m⁻2. CEO release followed the Avrami model (R2 = 0.9992), confirming controlled-release behavior. Fruit preservation tests demonstrated reduced mass loss (from 38.5% to 18.3% for blueberries) and maintained visual quality of blueberries and green grapes over 9 days. These results demonstrate that CEO@GMA-NH2-UiO-66 is a promising additive in starch-based active packaging films for fruit preservation. CEO@GMA-NH2-UiO-66 is developed as a porous carrier for clove essential oil. GMA-NH2-UiO-66 exhibits a high CEO loading capacity of 780.3 ± 6.5 mg/g. The 2 wt% CEO@GMA-NH2-UiO-66 film achieves 23.8 MPa tensile strength. The active starch film enables controlled CEO release and improves fruit preservation.