The physicochemical, mechanical, and antifungal properties of sodium alginate film containing Japanese rice vinegar and peppermint (Mentha piperita) oil as bio-composite packaging

Sodium Alginate has a high demand and is favored for food packaging; however, this film typically exhibits poor antimicrobial activity. In this study, sodium alginate film containing peppermint essential oil, Japanese rice vinegar, or a combination of both, is used to analyze antimicrobial, mechanical, structural, and optical properties. The scanning electron microscopy (SEM) technique is utilized to observe the film's surface and cross-section homogeneity. The addition of peppermint essential oil and Japanese rice vinegar to the alginate film solution improves fungal growth and spore germination prevention. Unlike the film containing vinegar, the film with peppermint essential oil shows the lowest transparency. It also has the lowest tensile strength and exhibits the highest elongation at break and water vapor permeability. Conclusively, the film containing a combination of vinegar and essential oil indicates moderate values. According to AFM topography, the film with a mix of essential oil and vinegar has a smoother, more homogeneous surface than other films. Our results prove that combining vinegar and oil with sodium alginate film is an ideal choice. This combination significantly improves the performance of food packaging.