Multifunctional fermented cassava starch–chitosan films and coatings loaded with Hyssopus officinalis essential oil: Development, properties, postharvest preservation of cherry tomatoes

Hyssopus officinalis essential oil (HOEO) is a bioactive natural compound with well-documented antimicrobial properties; however, its functionalization within a fermented cassa v a starch (FCS)–chitosan composite matrix has not been explored. In this study, FCS–chitosan films containing HOEO at 0.2% and 0.4% ( v /v) were developed and systematically evaluated for their physicochemical, optical, morphological, and biological performance, as well as their efficacy in extending the shelf life of cherry tomatoes. HOEO incorporation significantly enhanced the structural integrity, moisture barrier properties, thermal stability, and ultraviolet light shielding of the films. Notably, the 0.2% HOEO formulation improved moisture barrier properties, reducing water vapor permeability (WVP) by 33% compared to the control. These improvements were attributed to synergistic interactions between HOEO droplets and the polymer matrix, which increased water vapor diffusion tortuosity, mitigated water-induced plasticization, and filled microstructural defects within the film network. During 20 days of storage at 25 °C and 60 ± 5% relative humidity, the 0.2% HOEO coating reduced cherry tomato weight loss by 42% and inhibited Botrytis cinerea decay by 74.5% compared to the uncoated control. Among all, the 0.2% HOEO formulation provided the optimal balance between quality preservation and antifungal efficacy. These findings demonstrate the potential of HOEO-incorporated FCS–chitosan coatings as a sustainable alternative to conventional packaging for reducing postharvest losses in fresh produce.