Preparation of PAN@TiO2 Nanofibers for Fruit Packaging Materials with Efficient Photocatalytic Degradation of Ethylene.

Ethylene causes faster deterioration of perishable crops during postharvest transportation and storage. The present study aimed to develop TiO2-coated nanofibers with efficient photocatalytic activities to enhance the degradation of fruit-emitted ethylene. The consecutive electrospinning of polyacrylonitrile (PAN) and TiO2 deposition was successfully performed to produce PAN@TiO2 nanofibers. The scanning electron microscopy results indicate the uniform distribution of TiO2 nanoparticles on the surface of the PAN nanofiber. The PAN@TiO2 composite nanofibers exhibited enhanced photocatalytic activity for ethylene degradation under low-intensity UV light irradiation. Furthermore, a tomato fruit-ripening test confirmed the effectiveness of the PAN@TiO2 nanofibers. The PAN@TiO2 nanofibers exhibited effective ethylene degradation and slowed the color shift and softening of the tomatoes during storage. The results suggest great potential for use of the PAN@TiO2 composite nanofibers as ethylene scavenging packaging material for fresh fruits and vegetables.

Encapsulation of Thymol in Biodegradable Nanofiber via Coaxial Eletrospinning and Applications in Fruit Preservation.

The application of the nanofiber film in the field of food preservation was an emerging research direction in recent years. With the functionalization of nanofibers, the quality and safety of food can be better guaranteed. In the present work, thymol as an antibacterial agent was encapsulated into poly(lactide- co-glycolide) to form core-shell nanofibers by coaxial electrospinning. With such a core-shell nanofiber film, thymol can be slowly released to headspace between food and the nanofiber film, inhibiting the growth of bacteria on the surface of food. The morphology and core-shell structure of nanofibers were confirmed by scanning electron microscopy and transmission electron microscopy. The antibacterial and fruit preservation abilities of the nanofiber film were tested on strawberries. Studies have shown that it can effectively inhibit the growth of bacteria, fungi, and yeast and extend the shelf life of fruit. This novel antibacterial packaging material with excellent biocompatibility, biodegradability, and good sustained release performance would have a broad application prospect in the field of food preservation.

DNAzyme tunable lead(II) gating based on ion-track etched conical nanochannels.

A simple biomimetic ionic gate has been developed by modifying lead(II) ion responsive DNAzymes onto the inner surface of ion-etched polymer nanochannels.