A transparent p-coumaric acid-grafted-chitosan coating with antimicrobial, antioxidant and antifogging properties for fruit packaging applications.

The study aimed to develop a novel, transparent and non-toxic coating with antimicrobial, antioxidant, and antifogging properties. The p-coumaric acid-grafted chitosan (CS-PCA) was synthesized via a carbodiimide coupling reaction and then characterized. The CS-PCA coatings were further prepared using the casting method. The CS-PCA coatings obtained exhibited excellent transparency, UV-light barrier ability, and antifogging properties, as confirmed by spectroscopy and antifogging tests. The CS-PCA coatings showed stronger antioxidant capacity and antimicrobial properties against Escherichia coli, Staphylococcus aureus and Botrytis cinerea compared to CS. The multifunctional coatings were further coated on the polyethylene cling film and their effectiveness was confirmed through a strawberry preservation test. The decay of the strawberries was reduced by CS-PCA coated film at room temperature.

Enzyme-responsive food packaging system based on pectin-coated poly (lactic acid) nanofiber films for controlled release of thymol.

Foodborne diseases caused by foodborne pathogens lead to serious harm to food safety and human health. This work fabricated an enzyme-responsive packaging film based on porous poly (lactic acid) (PLA) nanofibers modified by positively charged polyethyleneimine (PEI) and further to adsorb negatively charged pectin coating, which loaded with thymol (THY) for protecting fruits from microbial infection. The porous PLA nanofibers were fabricated by combining "Breath Figure" principle and electrospinning technique. The XPS and FTIR characterizations showed that PLA nanofiber membrane was successfully modified by PEI. The prepared nanofiber membrane significantly inhibited the growth of E. coli, S. aureus and Bacillus subtilis (＞95%), especially showed excellent antifungal activity against Aspergillus niger. The release of THY from pectin-coated porous nanofiber membrane (THY@PLA-PEI-Pectin) was triggered by pectinase, which was secreted by microorganisms from food contamination. Besides, the biocompatible THY@PLA-PEI-Pectin nanofiber membrane prolonged the shelf life of citrus. Therefore, this pectinase-responsive nanofiber membrane has desirable application prospects in the development of active or smart packaging systems.

Electrospun functional polymeric nanofibers for active food packaging: A review.

With the increasing demand for food quality and food safety, it is urgent to develop efficient packaging strategies for prolonging the shelf life of food. Functional polymeric nanofibers have emerged as promising packaging materials and made tremendous breakthrough in food packaging field. Electrospinning technique is recognized as a versatile and high-efficiency method to produce nanofibers with multifunctional properties and adjustable structures. This review focus on electrospinning types and structural construction of nanofibers (uniaxial, core-shell and porous structures) as well as highlighted the advanced functionality of polymeric nanofibers in active packaging. Moreover, the emerging stimuli-responsive nanofibers for controlled release of active compounds were introduced in this review. Ultimately, the existing challenges, future prospects and development directions of nanofiber-based packaging materials were also discussed, which will facilitate the utilization of electrospinning nanotechnology in food industry.

Electrospun pullulan/PVA nanofibers integrated with thymol-loaded porphyrin metal-organic framework for antibacterial food packaging.

Pathogenic microorganisms posed perniciousness for postharvest fruits and vegetables, as well as brought potential risks for human health. In this work, pullulan/polyvinyl alcohol (PUL/PVA) nanofibers incorporated with thymol-loaded porphyrin metal-organic framework nanoparticles (THY@PCN-224 NPs) were developed for antibacterial food packaging. PCN-224 MOFs not only act as thymol loading carriers but also highly produce singlet oxygen (1O2) with bactericidal activity. PUL/PVA nanofiber was a promising sustainable substrate because of its good flexibility, biocompatibility and biodegradability. The loading capacity of PCN-224 for thymol was about 20%. The THY@PCN/PUL/PVA nanofibers exhibited synergistic antibacterial activities against E. coli (~99%) and S. aureus (~98%) under light irradiation. The cell viability assays and fruit preservation study demonstrated good biosafety of the polymeric film. The results suggested that this novel nanofiber has potential application prospects for food packaging.