<![CDATA[The environmental impact of conventional plastic food packaging has driven the development of biodegradable and edible materials from renewable resources. Chitosan, a biopolymer derived from chitin, is a promising candidate due to its biodegradability, film-forming ability, and antimicrobial activity. However, pure chitosan-based edible films are limited by low mechanical strength, high water vapor permeability, and variable antimicrobial performance. This study evaluated the combined effects of solvent type, fatty acid incorporation, and sodium benzoate addition on the physical, mechanical, barrier, microstructural, and antimicrobial properties of chitosan-based edible films. Chitosan edible films were prepared by solution casting using acetic acid and lactic acid as solvents. Stearic acid and oleic acid were incorporated at 2% and 5% (w/w of chitosan), with sodium benzoate added at 0 and 0.03%. Film properties were analyzed in terms of pH, water activity, optical properties, thickness, tensile strength, elongation at break, WVTR, microstructure (SEM), and antimicrobial activity against Staphylococcus aureus and Escherichia coli. Acetic acid–based films showed higher tensile strength and lower WVTR, whereas lactic acid–based films exhibited greater elasticity. Stearic acid improved moisture-barrier performance and microstructural homogeneity, while sodium benzoate enhanced antimicrobial activity, particularly against S. aureus. It can be concluded that Chitosan dissolved in 1% acetic acid with 5% stearic acid and sodium benzoate provided the most balanced mechanical, barrier, and antimicrobial performance, supporting its potential as sustainable food packaging.]]>
