Preparation and characterization of a starch-based active packaging with pH-sensitive release via tea tree essential...

Tea tree oil (TTEO) is a natural active agent, but less stable. In this research, a covalent organic frameworks, CTB, is prepared, and used to load TTEO (CTB@TTEO), and then CTB@TTEO as the filler is used to prepare starch-based active packaging films for storage blueberries. The results show that CTB@TTEO could increase the mechanical strength, gas barrier, antioxidant activity, and bacteriostatic activity of the thermoplastic starch film. The starch-based active packaging film with 2 wt% CTB@TTEO possesses the superior preservation effect on blueberry fruits. It is due to that the starch-based active packaging film with 2 wt% CTB@TTEO has the most compact structure, and displays outstanding bacteriostatic activity for Staphylococcus aureus and Escherichia coli. In addition, CTB@TTEO exhibits a pH-sensitive release characteristics. The release dynamics of TTEO in CTB@TTEO conform Avrami models. Consequently, the starch-based active packaging with 2 wt% CTB@TTEO has a promising application potential for fruit preservation.