Characterization and antibacterial activity of gelatin-based film incorporated with Arbutus unedo L. fruit extract on Sardina pilchardus

Gelatin-based films incorporated with Arbutus unedo fruit extract (AFE) were prepared and characterized. LC-DAD analysis demonstrated that the most abundant phenolic compounds in AFE were procyanidin B2 and gallic acid. The incorporation of AFE in gelatin tested film (TF) caused a remarkable decrease in water vapor permeability (5.01 × 10–9 g.mm/h.cm2.Pa) compared to control films (CF). FTIR analyses presented a broadening of amide A and I bands in the spectrum corresponding to the tested film. Films were used to coat samples on fresh fillets of Sardina pilchardus intentionally inoculated with Staphylococcus aureus, Listeria monocytogenes, and Pseudomonas aeruginosa. Fish samples were stored refrigerated for 12 days; TF exhibited important antimicrobial activity against the tested bacteria, especially against S. aureus. The obtained results will encourage the use of gelatin-based film containing AFE extract in active food packaging systems to control surface contamination by foodborne pathogenic microorganisms. Novelty impact statement: A. unedo extract (AFE) decreased gelatin water vapor permeability and contributed to the formation of hydrogen bonds between the phenolic compounds and the protein matrix. Active gelatin films were able to exert a remarkable antibacterial effect against S. aureus, L. monocytogenes, and P. aeruginosa, intentionally inoculated into sardine fillets. This study demonstrated that the application of gelatin-based film containing AFE on fresh sardine fillets could have the potential in controlling the growth of pathogenic and spoilage bacteria.