Construction of Pickering Emulsion of Amomum tsaoko Essential Oil Based on Cellulose Nanocrystals to Enhance Pullulan Film: Structure, Antibacterial Property, and Preservation Effect of Mango

Mango is prone to postharvest microbial infection, which leads to deterioration. Although essential oils show great potential for antibacterial and antioxidant applications, their effectiveness is limited by poor stability. In this study, cellulose nanocrystal (CNC)-stabilized Amomum tsaoko essential oil emulsion (AEO–CNC) was incorporated into a pullulan (Pul) matrix through hydrogen bonding to prepare antibacterial films. A stable AEO–CNC emulsion was obtained by precisely adjusting the AEO concentration. The effects of emulsion incorporation on microstructure evolution, molecular interactions, physiochemical properties, and biological functionalities of Pul-based composite films were systematically investigated, and their preservation effect on mango was evaluated. With the increasing incorporation of AEO Pickering emulsion, the ultraviolet-blocking property (transmittance <30%), antioxidant capacity (46.83%), and antibacterial activity of PP-CNC-AEO films were significantly improved. In addition, these films exhibited excellent mechanical properties (tensile strength of 30.62 MPa) and thermal stability. The PP-CNC-AEO films had a more uniform and compact surface structure, with no bubbles and fewer internal pores, which indicates the formation of an effective cross-linked network. When PP-CNC-50%AEO-F was used to preserve mango, it reduced weight loss, delayed the increase in soluble solids, and postponed the post-ripening process, exhibiting strong potential for extending the shelf life of fruit.