BACTERICIDAL PROPERTIES OF ALGINATE POLYMER FILMS INCORPORATED WITH NANOEMULSION OF SCHINUS TEREBINTHIFOLIUS ESSENTIAL OIL

Objective: This study aimed to develop alginate polymeric films incorporated with nanoemulsion of Schinus terebinthifolius essential oil and evaluate their bactericidal properties against foodborne pathogenic bacteria. Methods: The essential oil was extracted by hydrodistillation and characterized by GC-MS. Nanoemulsions were prepared by phase inversion method and incorporated into alginate films by casting. Antimicrobial activity was assessed by determining Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against eight bacterial strains (E. coli, S. aureus, S. enterica, P. aeruginosa, K. pneumoniae, S. pneumoniae, L. monocytogenes, E. faecalis) using the broth microdilution method. Results: GC-MS analysis revealed β-pinene (46.85%), α-pinene (18.55%), and germacrene D (17.06%) as the major constituents. The biofilm-nanoemulsion system exhibited broad-spectrum antimicrobial activity, with MIC values ranging from 51.7 to 93.3 mg/L and MBC values from 90.4 to 179.5 mg/L. Enhanced activity against Gram-negative bacteria was observed, particularly against E. coli (MIC = 51.7 mg/L) and P. aeruginosa (MIC = 54.6 mg/L). The low MBC/MIC ratios (1.1–2.1) confirmed the bactericidal nature of the system. Conclusion: The alginate films incorporated with nanoemulsion of S. terebinthifolius essential oil demonstrated promising bactericidal properties against a broad spectrum of foodborne pathogens. The enhanced antimicrobial efficacy was attributed to nanoemulsification and controlled release from the alginate matrix, indicating that this system represents a natural and sustainable alternative for active food packaging applications.