Cinnamon Essential-Oil-Loaded Fish Gelatin–Cellulose Nanocrystal Films Prepared under Acidic Conditions

The aim of this study was to characterize films obtained from fish gelatin (GelA, 3% w/w), encapsulated with cinnamon essential oil (CEO, 0.03–0.48% v/w), and loaded with bacterial cellulose nanocrystals (BCNCs, 0.06% w/w) at pH = 3.5. CEO-GelA/BCNC films were prepared by casting, and thickness, light transmittance (TT) and haze (H), surface hydrophobicity, tensile properties, chemical composition, and water solubility (WS) thereof were assessed. All films displayed outstanding optical properties (TT > 89.4%), with haze slightly exceeding a 3% value only at the highest CEO loading within the nanoemulsion formulation. The CEO plasticizing effect increased the elongation at break (EAB, from 0.84% up to 3.79%) and decreased the tensile strength (TS, from 8.98 MPa down to 1.93 MPa). The FT-IR spectra of films revealed good interaction among nanoemulsion components via hydrogen bonding. The CEO hydrophobic nature negatively impacted the WS (from 52.08% down to 8.48%) of the films. The results of this work confirmed the possibility of producing packaging systems from renewable sources to be potentially used in the form of edible films/coatings for the preservation of water-sensitive food products, both vegan-based (fruits/vegetables) and animal-based (meat/seafood).