Active biodegradable food packaging: effects of garlic essential oil incorporation on the degradation of cellulose acetate films in soil

Abstract Cellulose acetate films represent a promising alternative to petroleum‐based plastics for active antimicrobial packaging, with potential to enhance food safety and extend the shelf life of meat products. However, high essential oil concentrations can impair polymer biodegradability, creating a trade‐off between antimicrobial efficacy and environmental sustainability. This study investigated the effect of incorporating 1.5% (w/w) garlic essential oil (GEO) on cellulose acetate film degradation during a 180‐day soil burial experiment. Films were characterized by visual inspection, instrumental color analysis (luminosity, hue angle, chroma, opacity), SEM, mass loss, TGA, mechanical testing and XRD. During burial, films exhibited increased opacity, yellowing, microhole formation and progressive additive leaching, indicating surface and structural degradation. SEM revealed matrix erosion and exposure of internal layers, while TGA indicated early decreases in onset decomposition temperature ( T onset ) in GEO‐containing films, suggesting accelerated molecular weakening. XRD analysis demonstrated increased crystallinity, occurring faster in active films, reflecting structural rearrangements facilitated by the initial plasticizing effect and subsequent GEO leaching. Mechanical testing revealed distinct molecular‐level degradation pathways, although final properties were comparable between control and active films. The optimized GEO concentration preserved antimicrobial functionality while enabling effective environmental biodegradation, reversing the inhibitory effects observed at higher concentrations. These findings provide robust mechanistic insights for the development of active, biodegradable films that balance functional performance with environmental sustainability, offering a model applicable to the packaging industry. © 2025 Society of Chemical Industry.