BACTERICIDAL PROPERTIES OF ALGINATE POLYMER FILMS INCORPORATED WITH NANOEMULSION OF PIMENTA DIOICA ESSENTIAL OIL

Objective: This study aimed to develop alginate polymeric films incorporated with nanoemulsion of Pimenta dioica 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 eugenol (78.96%), chavicol (8.78%), myrcene (3.52%), and limonene (2.16%) as the major constituents. The biofilm-nanoemulsion system exhibited broad-spectrum antimicrobial activity, with MIC values ranging from 41.4 to 74.6 mg/L and MBC values from 72.3 to 143.6 mg/L. Enhanced activity against Gram-negative bacteria was observed, particularly against E. coli (MIC = 41.4 mg/L) and P. aeruginosa (MIC = 43.7 mg/L). The low MBC/MIC ratios (1.1–2.1) confirmed the bactericidal nature of the system, with the nanoemulsion demonstrating comparable or superior activity to conventional antibiotics vancomycin, gentamicin, and ampicillin against several strains. Conclusion: The alginate films incorporated with nanoemulsion of Pimenta dioica essential oil demonstrated promising bactericidal properties against a broad spectrum of foodborne pathogens.