Modified silica immobilized cinnamaldehyde-AgNPs/chitosan/polyethylene oxide spun packaging film for cherry preservation

During the preservation process, it is crucial to minimize the invasion of microorganisms, regulate the respiratory and metabolic activities of fruits, and how to coordinate the two to maintain the quality of fruits. Herein, modified hollow mesoporous silica nanospheres ( NH 2 -HMSN) was used to graft cinnamaldehyde (CA) and immobilize silver nanoparticles (AgNPs), synthesizing NH 2 -HMSN@CA/Ag preservative. Subsequently, the NH 2 -HMSN@CA/Ag was combined with chitosan and polyethylene oxide to obtain nanofiber film (CPNS@CA/Ag) by electrospinning, and utilized for the cherry preservation. The intricate physical entanglement and robust hydrogen bonding interactions between chitosan and polyethylene oxide, coupled with synergistic interfacial engagement with NH 2 -HMSN@CA/Ag, collectively confer the CPNS@CA/Ag nanofibers with three-dimensional network structure. The unique nanofiber structure endows CPNS@CA/Ag film with controllable oxygen (4.11 g/m 2 ·h·kpa) and moisture (357.9 g·mm/m 2 ·d·kpa) permeability and a long-lasting release effect (88.81% of CA and 7.76% of AgNPs released in 7 days). Crucially, the CPNS@CA/Ag film demonstrates potent antioxidant activity, hydrophobic performance (water contact angle is 105.6°), antimicrobial activity (99.99% inhibition rate), and favorable safety profile (silver residual amount < 0.03 mg/kg). These performances confer strong freshness-preserving efficacy to the CPNS@CA/Ag nanofiber film packaging for cherries, thereby extending the storage duration at 25 °C to 12 days. This study presents the development of a modified silica-reinforced chitosan-based electrospun film, which enables the controlled release of both cinnamaldehyde and AgNPs, exhibiting enhanced biosafety and preservation efficacy for postharvest fruit application.