Chitosan/PVA active packaging films incorporated with tea tree oil: Enhancing postharvest quality of cherry tomatoes by regulating cell wall metabolism and antioxidant capacity.

To address the challenges of poor stability and uncontrolled release of volatile active compounds in food packaging, this study developed a chitosan (CS)-stabilized tea tree oil (TTO) nanoemulsion (NEs), which was incorporated into a polyvinyl alcohol (PVA) matrix to prepare composite nanofiber films (CTNF) by emulsion electrospinning. Its preservation performance was evaluated through a cherry tomato storage test. The NEs exhibited good stability when formulated with 1.5% (w/v) chitosan , 0.60% (w/v) Tween 80, and 1.72% (w/v) oil phase. When the NEs loading was 20%, the resulting nanofiber film exhibited radical scavenging activities of 59.44 ± 0.35% against ABTS+ radicals and 33.72 ± 0.43% against superoxide anion radicals, and inhibition rates against Escherichia coli and Staphylococcus aureus of 87.79 ± 0.89% and 82.19 ± 0.28%, respectively. CTNF showed a biphasic TTO release behavior, consisting of an initial rapid release followed by a slower sustained-release phase, thereby enhancing the antibacterial durability of the active packaging. Among the tested formulations, the CTNF/20% NEs film effectively maintained the quality of cherry tomatoes and extended the storage period to 12 d under ambient conditions.