Cinnamon Essential Oil-Loaded Fish Gelatin-Cellulose Nanocrystals Active Films Prepared Under Acidic Conditions

Films obtained from a main biopolymer phase of 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 were characterized. CEO-GelA/BCNCs films were prepared by casting and analyzed in terms of thickness, light transmittance (TT) and haze (H), surface hydrophobicity, tensile properties, chemical composition, and water solubility (WS). All tested films displayed outstanding optical properties (TT > 89.4%), with haze slightly exceeding a 3% value only when the highest CEO loading was used during nanoemulsion preparation. The CEO plasticizing effect yielded an increase in the elongation at break (EAB, from 0.84% up to 3.79%), which corresponded to a decrease in tensile strength (TS, from 8.98 MPa down to 1.93 MPa). The FT-IR spectra of films revealed a good degree of interaction among single nanoemulsion components via hydrogen bonding. The intrinsic hydrophobic nature of the CEO negatively impacted the WS (from 52.08% down to 8.48%) of the films. Results obtained in this work confirmed the possibility to produce packaging systems from renewable sources to be potentially used in the form of edible films/coatings for preserving water-sensitive food products, both vegan-based (fruits/vegetables), and animal-based (meat/seafood).