Development of pH-Sensitive Active Chitosan Films Loaded with <i>Terminalia chebula</i> Oil Nanoemulsion and Ixora Flower Anthocyanins with Antimicrobial and Antioxidant Activities

This study aimed to fabricate pH-responsive active chitosan films reinforced with the Ixora flower extract and Terminalia chebula fruit oil-based nanoemulsion and evaluate their physicochemical properties. The effects of the Ixora flower extract and the nanoemulsion on the mechanical, physical, and active properties of the chitosan-based films were explored. The results indicated that the anthocyanin-rich Ixora flower extract imparts distinct color changes in acidic, neutral, and basic media (pH = 2–12) introducing the pH sensing property, while the nanoemulsion endows the film with excellent antioxidant activity and antimicrobial properties against common foodborne pathogens Escherichia coli and Staphylococcus aureus bacteria. Nanoemulsion incorporation enhanced tensile strength, UV barrier properties, and water contact angles while reduced water vapor permeability and solubility. Films containing both the nanoemulsion and the flower extract showed multifunctional properties, including antimicrobial, antioxidant, and pH sensing activities along with enhanced mechanical and barrier properties, making them useful for active food packaging applications.