A high-performance chlorogenic acid-allicin-porphyrin-carboxymethyl chitosan/sodium alginate composite film: Synergizing potent antibacterial protection with innate biocompatibility for sustainable fruit preservation

This study reports on the development of an innovative Chlorogenic acid-allicin-porphyrin-CMCS/SA composite film designed for fruit preservation through coating applications. Chlorogenic acid (CA) and allicin were polymerized via precipitation to synthesize CAA nanoparticles, which then adsorbed cationic porphyrin through charge interaction mechanisms to form chlorogenic acid-allicin-porphyrin (CAAT) composite nanoparticles. This antimicrobial component exhibits significant photosensitivity. These nanoparticles were incorporated into a film matrix composed of carboxymethyl chitosan and sodium alginate (CMCS/SA). The CAAT-CMCS/SA composite film was fabricated using a solution-blending technique, integrating the photosensitive antibacterial agent uniformly within the polymeric network. A comprehensive investigation was conducted to characterize the structural properties of the CAAT nanoparticles and their capacity to generate reactive oxygen species (ROS) under visible light irradiation. The functional attributes of the composite film—including ultraviolet (UV) shielding efficiency, water solubility, antimicrobial performance, biocompatibility, and efficacy in fruit preservation—were systematically evaluated. Experimental findings confirmed that the CAAT-CMCS/SA composite film possesses strong UV-blocking capability (>80%), high transparency (>85%), facile washability (4 min), significant antibacterial activity (100%), and effective fruit preservation performance. These results underscore the potential of this composite film as a promising material for advanced food preservation packaging.