The objective of this work is to explore a new pathway to develop active packaging materials. Currently, controlled release materials have attracted considerable attention in food packaging applications. In this study, the thyme essential oil (TEO) was loaded in electrospinning porous poly(lactic acid) (PLA) nanofibers and coated with poly(vinyl alcohol)/poly(ethylene glycol) (PVA/PEG) blends for humidity-controlled TEO release. The images of scanning electron microscope displayed uniform pores distributed on the surface of PLA nanofibers. Water contact angle measurement indicated that PVA/PEG coating provided the packaging film with excellent hydrophilicity. ATR-FTIR spectral analysis supported the chemical composition of the films. The antibacterial activities of PLA/TEO/PVA/PEG films against Escherichia coli and Staphylococcus aureus reached ＞99%. Furthermore, the weight loss and firmness of strawberries packaged with this novel film were evaluated. Finally, the in vitro release behaviors of TEO were evaluated and the results demonstrated that the release rate could be controlled by adjusting the humidity (20% RH to 80% RH).
The development of safe, environmentally friendly, edible antimicrobial packaging films represents a promising alternative to conventional plastic packaging for reducing spoilage and extending the shelf life of fresh food. Here, we propose a novel strategy to construct edible β-CD-MOF/carvacrol@zein (BCCZ) composite films by intertwining β-CD-MOF loaded with the antimicrobial essential oil carvacrol, and zein. The resulting BCCZ films exhibit high humidity-triggered, long-lasting bactericidal efficacy, effective fruit preservation, and excellent biosafety. Characterization revealed that BCCZ films possess a compact texture, hydrophilic surface, low water vapor permeability, and high humidity sensitivity. Additionally, this film act as a “storehouse” for carvacrol, enabling humidity-controlled release (96.3% release at 100% RH and only 12.0% at 43% RH on day 7). BCCZ film effectively inhibited Gram-positive Staphylococcus aureus , Gram-negative Escherichia coli , and fungi ( Botrytis cinerea ) through the release of liquid-phase and vapor-phase carvacrols under both direct contact and indirect contact conditions in high humidity. Owing to the film's humidity-triggered, long-term release of carvacrol, strawberries packed in BCCZ films maintained their freshness and appearance significantly better after seven days of storage at 21 °C. This work provides valuable insights and holds promise for the design and commercial application of safe, environmentally friendly freshness-preserving packaging films.
危险品化学品经营许可证（带存储）