Eco-friendly bioactive ?-caryophyllene/halloysite nanotubes loaded nanofibrous sheets for active food packaging

We fabricated Zein/polycaprolactone (PCL) electrospun nanofiber sheets incorporated with different concentrations of beta-caryophyllene loaded into halloysite (HNT) nanotubes as an eco-friendly, bioactive food packaging material. We obtained heterogeneous fibers with flat ribbon-like morphology. The loading of beta-caryophyllene/ HNT increased the fiber diameters from -900 nm to -1100 nm. The nanofiber showed improved thermal and mechanical performance upon incorporating beta-caryophyllene/HNT. The water vapor permeability decreased due to a decrease in the porosity of the nanofiber sheets. The beta-caryophyllene/HNT loaded nanofiber showed good DPPH free radical scavenging and was effective against both gram-positive B.subtilis and gram-negative E.coli bacteria subjected to agar disc diffusion test and time-kill study. The initial release of beta-caryophyllene from the 5%, 10%, and 20% loaded nanofiber sheets was -22%, -25%, and -31% within 12 h, and -63%, -69%, and -77% after 120 h indicating a sustained slow release for long term bioactivity. The WST-1, LDH, and cell adhesion properties of beta-caryophyllene/HNT-loaded nanofiber render them biocompatible and nontoxic. Composting experiment reveals the eco-friendly nature of the fabricated nanofiber sheets as they all lose their fibrous morphology after 21 days of composting and a mass loss of -65% for Zein/PCL nanofibers and -63%, -55%, and -48% for 5%, 10%, and 20% beta-caryophyllene/HNT loaded Zein/PCL nanofiber sheets. During the application test for postharvest quality preservation of strawberries, the strawberries covered in Zein/PCL-20 showed the best-preserved quality after 4 days of storage at 25 degrees C in 40% humidity. The physicochemical, biological, and application tests demonstrated the potential of the prepared nanofiber sheets as a potential bioactive food packaging material.

Automated summary

We fabricated Zein/polycaprolactone (PCL) electrospun nanofiber sheets incorporated with beta-caryophyllene loaded into halloysite (HNT) nanotubes, which can serve as an eco-friendly, bioactive food packaging material. The nanofiber sheets showed improved thermal and mechanical performance, reduced water vapor permeability, and exhibited good antioxidant and antibacterial properties. They also demonstrated sustained slow release of beta-caryophyllene and biocompatibility. The fabricated nanofiber sheets showed environmental degradation and effectively preserved the quality of strawberries during storage.