Fabrication of BODIPY/polyvinyl alcohol/alkaline lignin antibacterial composite films for food packing

Recent advances in research on biomass-based food packaging film materials

Although traditional petroleum-based packaging materials pose environmental problems, biodegradable packaging materials have attracted extensive attention from research and industry for their environmentally friendly properties. Bio-based films, as an alternative to petroleum-based packaging films, demonstrate their significant advantages in terms of environmental friendliness and resource sustainability. This paper provides an insight into the development of biomass food packaging films such as cellulose, starch, chitosan, and gelatine, including their properties, methods of preparation (e.g., solution casting, extrusion blow molding, layer-by-layer assembly, and electrostatic spinning), and applications in food packaging. Through these preparation methods, the paper analyzes how the properties of the films can be effectively tuned and optimized to meet specific packaging needs. It was found that biomass film materials for food packaging not only possess functional properties such as antimicrobial, preservation, and indication, but also that their continued material innovation and technological improvements offer promising prospects for their use in commercial applications. These advances could help advance the global sustainable development goals, while showing great potential for improving food safety and extending shelf life. Future research will further explore new functions and applications of biomass films, providing additional solutions for environmental protection and sustainability.

Silver nanoparticles/carbon dots nanocomposite with potent antibiofilm and long-term antimicrobial activity doped into chitosan/polyvinyl alcohol film for food preservation

Exploration of robust antiseptics with antibiofilm performance and long-term antimicrobial activity is of great significance to effectively destroy foodborne pathogenic bacteria. Herein, a silver nanoparticles (Ag NPs) /carbon dots (CDs) nanocomposite (Ag@CDs) was constructed by the reaction of Ag+ with CDs, which has strong antibacterial ability, and mighty biofilm inhibition and destruction ability toward E. coli and S. aureus. Notably, low concentration of Ag@CDs (40.0 and 80.0 μg/mL) could ablate 86.11 % E. coli and 75.86 % S. aureus biomass of mature biofilm. To our knowledge, this is the first bactericide with powerful biofilm destruction activity. In addition, Ag@CDs exhibited long-term (30 d) antibacterial effect on the substrates of plastic, cotton, gauze, and glass. Ag@CDs was evenly dispersed into the matrix of chitosan (CS)/polyvinyl alcohol (PVA) to fabricate well-blended food packaging films. Among which, the 3 % Ag-CP film exhibited improved mechanical performance, excellent UV-Vis light blocking ability, and intensive antimicrobial activity. Despite seven days of storage, 3 % Ag-CP still could preserve the freshness and safety of the pork and shrimp, certifying it extends the storage life of packaged foods.

Development and Analysis of Silver Nitroprusside Nanoparticle-Incorporated Sodium Alginate Films for Banana Browning Prevention

Banana (Musa acuminate) has been popular among consumers worldwide due to its rich nutrients and minerals. However, bananas are highly susceptible to the physical and biological factors that lead to postharvest loss during transportation and storage. In this work, novel sodium alginate (SA) films incorporated with silver nitroprusside nanoparticles (AgNNPs) were prepared to extend the shelf life of bananas through antibacterial and antioxidant coating. The results exhibited that AgNNPs were cubical and that their size was <500 nm, with metal composition being Ag and Fe. Additionally, the incorporation of AgNNPs in the SA film was seen in FE-SEM and zeta analysis, with an average size of about 365.6 nm. Furthermore, the functional and crystalline properties of AgNNPs were assessed through FTIR and XRD. Transmittance testing of the SA-AgNNPs films confirmed they have good UV barrier properties. SA-AgNNPs films exhibited excellent high antibacterial activity against foodborne pathogens including L. monocytogenes, S. enterica, and E. coli at the concentration of 500 µg/mL. Moreover, during the storage of bananas, SA-AgNNPs nanocomposite coatings act as a barrier to microbial contamination and slow down the ripening of bananas. As a result, compared with SA-coated and uncoated bananas, SA-AgNNPs-coated bananas exhibited the lowest weight loss and lowest total bacterial colonies, thus greatly extending their shelf life. Particularly when coated with SA-AgNNPs films, total bacterial colonies (TBC) in the banana peel and pulp were as low as 1.13 × 103 and 51 CUF/g on the ninth day of storage, respectively. Our work offers an efficient strategy to improve the quality of bananas during the postharvest period, with extensive applications in fruit preservation and food packing.