Fabrication of green light activated ethyl cellulose/erythrosine B photobactericidal film and its application in salmon fillets preservation

In this study, photobactericidal films exhibiting excellent antibacterial activity upon irradiation under green light (530–545 nm) were prepared by incorporating erythrosine B (EB) into ethyl cellulose (EC) film. The results of Fourier-transform infrared spectra illustrated that the EB was successfully encapsulated in the films. Additionally, the EC/EB films exhibited a semi-transparent magenta hue with some UV blocking properties. As the amount of EB added to the EC films increased the tensile strength decreased from 22.79 MPa to 9.09 MPa, and the elongation at break increased from 8.20 % to 30.80 %. Under green light irradiation, the EC/EB films showed strong antibacterial activity (> 99 % bacteriostasis rate for Staphylococcus aureus and Escherichia coli ). Research on antibacterial mechanisms implied that the reactive oxygen species generated via photochemical pathways, caused damage to the bacterial cell membrane, leading to the leakage of substances within the bacterial cells and ultimately resulting in the death of the bacteria. Finally, the EC/EB films were applied to the preservation of salmon fillets, and the results showed the EC/EB films could significantly inhibit the growth of spoilage bacteria, thereby extending the shelf life by 2–3 days. Therefore, the prepared photobactericidal films have more potential for application in aquatic products preservation.